Cruisers Forum
Main Forum => General Discussion => Topic started by: 2 Lucky on December 13, 2020, 06:29:38 pm
-
Does anyone know of a way to safely supply whole house power from the 4000 Onan in case of power outage? I know I could run extension cords to alternately run the fridge, freezer, and a floor fan to circulate air from the NG fireplace. I'd like to be able to supply power to the house thermostats and circulator pumps for the NG baseboard heat.
It looks like most backup systems are 220v, and the Onan is 110v. tymote
Dougn
-
Doug,
I'm not an electrician, but I have an electronics background, do all my own electrical work, and have a pretty good handle on it. With those caveats, I'm afraid the short answer when you're talking "whole house power" is no. You pretty well already identified the usability of the Onan to support household emergency needs. The Onan is rated to provide a total 33.3 amps at 120 volts. The realistic use would be to run a couple of extension cords plugged in to two separate 20 amp circuits on the RV. That should allow you to tap up to 20 amps on either circuit, or theoretically 15-16 amps on both at one time, everything at 120 volts. There is no outlet on the RV that will let you pull the full 33 amps on one extension cord; a person could conceivably wire in an outlet at the transfer switch to tap the full generator output of 33 amps on one power cord, but that is still going to be at 120 volts, would be a pretty major project, and I doubt it would be worth the effort.
As you say, home backup systems are normally 240 volts, since that's the line power coming into your home. It consists of two separate 120 volt feeds or phases that each feed about half of the 120 volt circuits in your main panel, with the 240 volt circuits tapping across both phases. For backup power, that can only be supplied by a generator with a 240 volt output. Lower price 5000 watt units can be had for about $500 today, with higher wattage output units going up in price. Proper installation also would use a transfer switch to switch the input to your house main panel from the line in to the generator. You can get around that with a more simple hookup (I do), but you must know what you are doing or you will compromise safety.
You mention one objective is to supply power to "house thermostats and circulator pumps". I'm not familiar with that system (my home uses natural gas central heating), but if that circuit is 120 volt and 20 amps or less, it's possible you could tie in to the wiring for that particular circuit at your main panel and power it with an Onan extension cord. If it is a 240 volt circuit, it will require the 240 volt generator.
Mike
-
I agree with Mike, you are not going to have 'Whole House' generator backup off the RV.
However... if you are looking to run only the systems you named first-
""run the fridge, freezer, and a floor fan to circulate air from the NG fireplace. ""
You have a possible way to do that, and can do so to code.
Using this 30A generator transfer switch - https://www.lowes.com/pd/Reliance-306LRK-6-Circuit-Transfer-Switch-Kit-P2/50436688
(https://mobileimages.lowes.com/product/converted/815181/815181010683.jpg?size=pdhi)
You can safely supply up to (6) 110V circuits in your house. (The picture shows it configured for 1 220V and 4 110V, but it can be configured 110V only)
-Compatible with most generators that have a 20-amp or 30-amp 120/240 volt 4-wire receptacle
-Can be connected to 1-pole or 2-pole household circuits, up to 30 amps
The breaker panel would be wired into your house panel.
The 'supply receptacle' would mount outside, and be the connection point for your RV.
*******************************************************************************************
On the RV itself, as Mike said, you would need a 30A supply outlet. On my 2350, the transfer switch is located in the drivers B pillar, behind the seat. I would go into that junction box, and directly wire the RV outlet to the transfer switch input. (The generator breakers will be the safety) With a short connecting run to something like this:
https://www.hubbell.com/wiringdevice-kellems/en/Products/Electrical-Electronic/Wiring-Devices/Watertight-Devices/Watertight-Safety-Shroud-Twist-Lock/HBL2720SW/p/1638242
(https://hubbellcdn.com/prodimage515/WBP_HBL2720SW_PRODIMAGE_515.jpg)
The location of the transfer switch in your rig will determine the outlet location and wiring needs. When using the 'house powering outlet' I would turn off breakers in the coach as to eliminate any draw in there.
********************************************************************************
Now We have a safe 30A connection to the RV generator. We have a proper generator transfer panel inside the house. Just have to link them.
https://www.homedepot.com/p/Conntek-50-ft-10-4-STW-30-Amp-125-Volt-250-Volt-4-Prong-L14-30-Transfer-Switch-Cord-Generator-Extension-Cord-20602/309291375
(https://images.homedepot-static.com/productImages/21fa81cd-f8d5-4c37-81ba-c57a684217cc/svn/conntek-generator-cords-20602-64_145.jpg)
And now you have a 30A backup power circuit in your house that works off your RV. (cheer) Cost will depend on your abilities and other parameters the existing building and RV wiring may present.
*****************************************
And for the house heating system... ""I'd like to be able to supply power to the house thermostats and circulator pumps for the NG baseboard heat.""
It looks like you and Mike both have natural gas heat, I am guessing Mike has a forced air and you have a baseboard water system. (WH) Mike's I am guessing is 220V guaranteed. You need to do some research... check the circulator pumps and see if they are 220V or 110V. You didnt mention the boiler, where the NG is burned to heat the water. That usually supplies the power to the thermostats also. IF it is 110V, you are still in luck.
If the pumps and boiler both together pull less than 30A, you can wire them in with the transfer panel above and you are up and running! There are meters on the transfer panel that will help you monitor your power usage. If the boiler and pumps are 220V, or require more than 30A 110V to run, another generator will be required for house heat.
I WAS a registered chimney sweep and heating specialist, but 20 years ago in Vermont. Things may have changed in that world that I am unaware of. In Florida since 1994, so very little time spent ADDING heat to a house. roflol Excuse any ignorance I may show there.
So it is possible to use the RV safely as a backup generator, cost is up to you and your abilities. 2o2
-
Dougn
You absolutely must have some form of transfer switch that is "break before make"... That is, utility power and generator power are NEVER connected at the same time, even for an instant. 100% isolation 100% of the time.
The easiest and cheapest way to do that is via extension cords. Unplug from the wall, plug into the generator.
For your baseboard heat, as mentioned above, it cannot be a 220v system. If it's a single 120v line on your breaker box, then you can have an electrician wire a break before make transfer switch and wire that to an electric input box near where you store your PC.
To be honest, I am not sure the Onan can output enough power to handle the circulator pump, refrigerator and freezer all at once.
Thanks to uncle Sam, I took my stimulus check and bought a Honda 2200 generator and propane conversion kit for it (can use either gasoline or propane as fuel) along with a 30# propane tank and extension cords.
I may put a transfer switch on my gas fireplace so I can alternate between it and the freezer when needed.
Don
-
Thanks for the thorough replies. It looks like most of the parts will be needed whether you use a dedicated backup generator or the RV.
Volkeman, The problem I still see is that the Transfer switch box you show has a four wire input for a 120/240 generator supply, that's where I found myself stumped.
I have roof-top solar, and understand the need to not back-feed power without protection to the service lines.
Donc, my gas fireplace does put out a fair amount of heat, and works without electricity, except for the blower fan. I have some usb computer fans like these:
https://www.aga.org/natural-gas/delivery/how-does-the-natural-gas-delivery-system-work-/
that I could plug into my jump-starter to help move the air. I got them because my blower fan is really noisy, the computer fans are really quiet.
I already have plenty of extension cords, so I'll go the easy route. I worry most about long-term heat loss and freezing pipes, so I 'm going to try to figure out if I can supply temporary power to the boiler and circ pump, plus, I have a side-arm water heater, be nice to have hot water also.
-
Not sure what a side-arm water heater is, but none of the water heaters I have ever had (over the last 20 years or so, ever required electricity to run. I lost power for 3 1/2 days in Denver in the mid 90's and at least had hot water. I can't remember what we did, if anything, for heat.
-
Not sure what a side-arm water heater is, but none of the water heaters I have ever had (over the last 20 years or so, ever required electricity to run. I lost power for 3 1/2 days in Denver in the mid 90's and at least had hot water. I can't remember what we did, if anything, for heat.
A side-arm water heater has a heat exchanger connected to the boiler, requires a circ pump.
-
This is a very interesting subject.
I have wondered if there was an easy way to jury-rig something. In my head, I have wondered if this would "safely" work.
1) Flip "OFF" the main house breaker(s) to isolate the house from community power.
2) Turn off every small breaker that distributes power throughout the house.
3) Plug the PC generator into my 30amp outlet in the garage, but I wonder how to output 110V-30amps direct from the PC generator.
4) Turn on only one house-distribution breaker at any given time.
- Run our gas fired forced-air furnace until the house warms up. The 110V power required would be only for the furnace blower.
- Flip breakers to run the kitchen fridge until it shuts off.
- Flip breakers for other purposes as needed.
Being on a private well that requires 220V, that seems to be a "bust" just like a/c, but everything else just might work. Having our house 100% converted to LED light bulbs throughout should also make a difference. Where we live near Chicago, the focus is more on keeping the house warm in the winter rather than cool in the summer.
Does anyone know how to output 110V-30amp from their PC generator?
-
Volkeman, The problem I still see is that the Transfer switch box you show has a four wire input for a 120/240 generator supply, that's where I found myself stumped.
You just leave one disconnected, and bridge the transfer switch inside. The transfer switch is made to do that. The outlet on the RV will have one unconnected terminal. Easy peasey.
It looks like most of the parts will be needed whether you use a dedicated backup generator or the RV.
Well, yeah! You are using the RV as a backup generator. (exactly) With this setup you can easily put another generator on it.
And i never knew what a side arm water heater was, thanks for the enlightenment. :)(:
-
This is a very interesting subject.
I have wondered if there was an easy way to jury-rig something. In my head, I have wondered if this would "safely" work.
1) Flip "OFF" the main house breaker(s) to isolate the house from community power.
2) Turn off every small breaker that distributes power throughout the house.
3) Plug the PC generator into my 30amp outlet in the garage, but I wonder how to output 110V-30amps direct from the PC generator.
4) Turn on only one house-distribution breaker at any given time.
- Run our gas fired forced-air furnace until the house warms up. The 110V power required would be only for the furnace blower.
- Flip breakers to run the kitchen fridge until it shuts off.
- Flip breakers for other purposes as needed.
Being on a private well that requires 220V, that seems to be a "bust" just like a/c, but everything else just might work. Having our house 100% converted to LED light bulbs throughout should also make a difference. Where we live near Chicago, the focus is more on keeping the house warm in the winter rather than cool in the summer.
Does anyone know how to output 110V-30amp from their PC generator?
""Turn off every small breaker that distributes power throughout the house.""
:help TURN OFF THE BIG ONES TOO!!! THEY WILL BACKFEED ONE LEG!!! :help
I outlined how to put a 30A outlet on the RV above. It will use the generator breaker, and output 30A. I used the 4 prong outlet just to make the cord easy for 2Lucky's particular setup, you can use a 3 prong for 110v if you are backfeeding the 30A outlet. Just need a custom cord. (Male 3 prong twistlock to 30A RV male)
Common 'redneck' backfeed for the house is the dryer outlet. Handles 220V 50A input. We have one that reaches the dryer from the breaker box, and it is coiled inside the box. Down in the basement is the other end of a 50' cord that connects to the generator OUTSIDE. All breakers off, Remove box cover, unplug dryer, plug in generator cord. Turn on dryer breaker for the supply, and load breakers as needed.
Is it safe? NO. Do people do it? YES. (nod) Check laws in your area.
https://coopergeneratorservices.com/generator-illegal-backfeeding-dangerous/
Backfeeding is a dangerous and possibly illegal way to power your home by connecting your generator to an appliance outlet (like a dryer outlet) and allowing electrical power to flow in reverse. Power moves backward to your electrical panel and is redistributed throughout the house.
Powering your home this way is dangerous and possibly illegal. If the main breaker is not shut off, power backfeeds to the utility lines outside your home, potentially shocking a maintenance worker. In these situations, you are responsible for injury or death, and could be criminally prosecuted.
Using backfeeding to restore power to your home is dangerous because electrical loads are not balanced. Also, unbalanced loads are inefficient and put extra strain on your generator.
The setup in our house was done before I was there, I have NEVER used it. I know many people that do use them, however.
-
This is a very interesting subject.
I have wondered if there was an easy way to jury-rig something. In my head, I have wondered if this would "safely" work.
1) Flip "OFF" the main house breaker(s) to isolate the house from community power.
2) Turn off every small breaker that distributes power throughout the house.
3) Plug the PC generator into my 30amp outlet in the garage, but I wonder how to output 110V-30amps direct from the PC generator.
4) Turn on only one house-distribution breaker at any given time.
- Run our gas fired forced-air furnace until the house warms up. The 110V power required would be only for the furnace blower.
- Flip breakers to run the kitchen fridge until it shuts off.
- Flip breakers for other purposes as needed.
Being on a private well that requires 220V, that seems to be a "bust" just like a/c, but everything else just might work. Having our house 100% converted to LED light bulbs throughout should also make a difference. Where we live near Chicago, the focus is more on keeping the house warm in the winter rather than cool in the summer.
Does anyone know how to output 110V-30amp from their PC generator?
Ron,
The short answer to your basic question of "can this safely work" is yes. But it must be done with caution and complete understanding to meet the "safely" criteria. To begin with--it is truly "jury-rigging" as you say; and it is certainly not to code. And any electrical modifications that fall into the category of "jury-rigging" are inherently unsafe and dangerous unless you absolutely know what you are doing. Supplying auxiliary power to your home should absolutely be done through a transfer switch which, if properly installed, will protect your home, your auxiliary power source, and the community power line feeding your home. However I do provide emergency power to my home safely from an auxiliary generator through a back-feed type connection, which is essentially what you describe. In my case, it is a full 240 volts, and I energize my entire main panel. My generator is only about a 6KW unit, so it can't carry my central air conditioning, and I do monitor loads, but everything else is operable.
Your last question of how to output the PC generator is answered in my and especially Volkeman's comments above. You would need to tie in to the transfer switch on your PC to access the full generator output, and wire in a receptacle that will let you connect a 120 volt, 30 amp cord set to your garage outlet. With your house main breakers switched "OFF" to isolate you from community power (absolutely critical, and the first thing to do), you would then back-feed to your main panel through the circuit breaker that feeds your garage 30 amp circuit (that breaker must be "ON"). One limitation that you may not have considered is that since you are only feeding in 120 volts, you will only energize the one side of your main panel that carries the circuit breaker for your garage circuit. Other breakers on that side of the panel will have power, but none of the breakers on the other side of the panel will have it. It will come down to "luck of the draw" as to which other house circuits are on that panel side. That's the advantage of a 240 volt capable auxiliary generator--in that case, with the same back-feed process, you feed the main panel through a 240 volt breaker, which energizes both sides of the panel. In my case, I installed a 240 volt 60 amp sub-panel in my garage for outside power and lights, and that's where I tie in the generator. With the main breakers to my main panel switched OFF, and the 60 amp breaker to my sub-panel switched ON, my main panel has 240 volts back-fed from the sub-panel to all circuits. My generator breaker protects that feed, but in practice, I still keep my high amperage 240 volt breakers (A/C unit, electric dryer, etc) switched OFF to prevent accidental overloads. Even the small 6KW generator carries everything else easily (including my NG central heat blowers), so can remain pretty normal during outages. Last usage was only about a week ago, when we had a 24-hour outage on our rural electric cooperative system, and it was nice to have normal heat and power. In 2002 we had a severe ice storm and our outage stretched to 13 days in our rural area, that's when I first acquired the generator and established the hook-up.
Mike
-
Since my biggest concern over long term power outage is keeping the house warm, I think I may have a simple solution using the extension cord route.
In the attached picture you'll see the 120 wiring from the wall into a surface mount switch, which supplies power to the boiler, zone valve controller (which also controls the side-arm water heater) and the transformer for the thermostats.
Does anyone see any issue with moving the switch box over and replacing it with a wall outlet, then wiring a grounded plug and wire to supply power to the switch? I could then just unplug it from the wall and connect it to my PC. Is the power from the PC inverter or generator clean enough for the circuit board in the controller?
It looks like the two circulator pumps are .75 amp. and the controller 1.5 amp, 3 zone valves at .3 each...I could run it for hours off of the coach batteries or PC solar?
-
Since my biggest concern over long term power outage is keeping the house warm, I think I may have a simple solution using the extension cord route.
In the attached picture you'll see the 120 wiring from the wall into a surface mount switch, which supplies power to the boiler, zone valve controller (which also controls the side-arm water heater) and the transformer for the thermostats.
Does anyone see any issue with moving the switch box over and replacing it with a wall outlet, then wiring a grounded plug and wire to supply power to the switch? I could then just unplug it from the wall and connect it to my PC. Is the power from the PC inverter or generator clean enough for the circuit board in the controller?
It looks like the two circulator pumps are .75 amp. and the controller 1.5 amp, 3 zone valves at .3 each...I could run it for hours off of the coach batteries or PC solar?
Well, amp-wise you are looking great! No power needed for the boiler itself? (or is that part of the controller output?)
Your idea is VERY valid!
I would add a junction box with a 3-way switch, and a 110V male receptacle.
Put the three way switch in the hot wire before the existing switch. Wire it so when the 3-way is one way, house power supplies the switch. The 3-way in the other position would supply the extension cord power to the existing switch. That way there would be no combination that would have you accidently connecting the generator to the house power. The attached diagram may make this a little clearer, I only show the 'hot' wires.
-
Dougn,
Based on what I can garner from your photo and your description, looks like your plan will work. Total load you identify is 4 amps, or 480 watts--very nominal by any standards; an extension cord supply should handle that easily. I don't know what rating your main panel circuit breaker feeding that circuit carries; you may be protecting it with a higher rated breaker from the coach (20 amps), but I wouldn't think that a particular risk for a temporary service. For permanent circuits such as this a hard-wired connection is normally preferred to a plug-in, but in this case I think the convenience of being able to quickly switch supplied power is worth any small disadvantage. I actually did the same thing to my central gas heating blower supply for the same reason, before setting up my permanent auxiliary generator hook-up. At my first power outage, I disconnected my furnace feed from the original hard-wired box, moved the supply to a receptacle, and installed a plug on the furnace. Used an extension cord from my generator to give us heat until I got the permanent hook-up made. It's worked fine for 20 years.
I don't think you need to worry about the quality of the generator/inverter power. I think they'll be fine. My central system uses a circuit board to control all the functions and I've never had an issue on generator.
Mike
-
Adding a plug in line as Mike said is a good idea also, and does make sure you cannot backfeed through the supply. 2o2 I was aiming for a little more inspector-friendly setup.
**********************************************
Curious... I never did any NG burner work, they did not have NG service in our area. The boiler/heat exchanger uses no or negligible power? Even in forced air apps? Being used to oil fired, there was ALWAYS current draw just to make the heat.
The 5 ton AC in our house has a blower rated 3/4 HP or 4.6 amps @ 220V. So the blower alone is close to 1000w at full draw. 480 watts for a whole house heating system is FANTASTIC. (cheer) I cant even blow the air around our house for twice that power, much less run the heat pump or heat strips.
-
Volkeman, yes there is some power needed for the boiler. The gas valve is about .5 amp, not sure what the piezo igniter uses to light it, and the flue vent damper takes another .6 amps, all in all not a lot of juice. Interesting to think I can run it off of my PC solar system and inverter!
My fireplace has a pilot light, so no power needed there.
-
Adding a plug in line as Mike said is a good idea also, and does make sure you cannot backfeed through the supply. 2o2 I was aiming for a little more inspector-friendly setup.
**********************************************
Curious... I never did any NG burner work, they did not have NG service in our area. The boiler/heat exchanger uses no or negligible power? Even in forced air apps? Being used to oil fired, there was ALWAYS current draw just to make the heat.
The 5 ton AC in our house has a blower rated 3/4 HP or 4.6 amps @ 220V. So the blower alone is close to 1000w at full draw. 480 watts for a whole house heating system is FANTASTIC. (cheer) I cant even blow the air around our house for twice that power, much less run the heat pump or heat strips.
Volk,
That's why, in areas where it's available, natural gas is heating is typically significantly cheaper than electric. Certainly here in Oklahoma, and even at the higher prices for NG of today. In small systems (hot water heaters, 30K BTU open flame free-standing heaters, even the 50K BTU dual wall furnace in my grandson's house), there is no electricity used at all. Heat flow is by convection, and in standing pilot systems, a 750 millivolt thermopile heated by the pilot provides all the energy needed to hold in the pilot safety valve and activate the solenoid in the main gas valve as called for by the thermostat. In larger, more sophisticated units, such as my central furnace and 2 Lucky's unit, 120 volts supplies the control systems with the gas valve/thermostat circuit powered by 24 volt transformers, but power draw is still almost negligible. In his case there is no blower, but there are circulating pumps; my unit being forced air and 5 ton A/C uses the same 3/4 HP squirrel cage setup as yours.
Mike
-
.... you will only energize the one side of your main panel that carries the circuit breaker for your garage circuit. Other breakers on that side of the panel will have power, but none of the breakers on the other side of the panel will have it. ..
Mike
Mike,
One correction.... Not ONE side or other of the breaker box but every other breaker on either side. Each side carries both phases.
That way to get 220v for say an A/C, electric range, dryer, etc. you stack 2 breakers latched at the toggle switch on the same side of the box.
Or at least, every residential breaker box I have worked on (maybe 8 to 10
distribution boxes) was set up that way.
Don
-
You're exactly right Don--thinking about the two phases tying in to each side, but the connector busses do alternate side to side as they go down the panel. As you say, that is the way a dual breaker (240 volt unit) accesses both phases.
So to correct the comment to Ron, if you hook in a 120 volt back-feed to the panel, it is true that only one-half of your 120 volt breakers will be energized--but instead of them being only on one side of the panel it will be alternating breakers, top to bottom, on each side.
Thanks for the clarification, Don. Every box I've worked on is set up that way also. Getting old...........
-
This is a very interesting subject.
I have wondered if there was an easy way to jury-rig something. In my head, I have wondered if this would "safely" work.
1) Flip "OFF" the main house breaker(s) to isolate the house from community power.
2) Turn off every small breaker that distributes power throughout the house.
3) Plug the PC generator into my 30amp outlet in the garage, but I wonder how to output 110V-30amps direct from the PC generator.
4) Turn on only one house-distribution breaker at any given time.
- Run our gas fired forced-air furnace until the house warms up. The 110V power required would be only for the furnace blower.
- Flip breakers to run the kitchen fridge until it shuts off.
- Flip breakers for other purposes as needed.
Being on a private well that requires 220V, that seems to be a "bust" just like a/c, but everything else just might work. Having our house 100% converted to LED light bulbs throughout should also make a difference. Where we live near Chicago, the focus is more on keeping the house warm in the winter rather than cool in the summer.
Does anyone know how to output 110V-30amp from their PC generator?
Ron,
The short answer to your basic question of "can this safely work" is yes. But it must be done with caution and complete understanding to meet the "safely" criteria. To begin with--it is truly "jury-rigging" as you say; and it is certainly not to code. And any electrical modifications that fall into the category of "jury-rigging" are inherently unsafe and dangerous unless you absolutely know what you are doing. Supplying auxiliary power to your home should absolutely be done through a transfer switch which, if properly installed, will protect your home, your auxiliary power source, and the community power line feeding your home. However I do provide emergency power to my home safely from an auxiliary generator through a back-feed type connection, which is essentially what you describe. In my case, it is a full 240 volts, and I energize my entire main panel. My generator is only about a 6KW unit, so it can't carry my central air conditioning, and I do monitor loads, but everything else is operable.
Your last question of how to output the PC generator is answered in my and especially Volkeman's comments above. You would need to tie in to the transfer switch on your PC to access the full generator output, and wire in a receptacle that will let you connect a 120 volt, 30 amp cord set to your garage outlet. With your house main breakers switched "OFF" to isolate you from community power (absolutely critical, and the first thing to do), you would then back-feed to your main panel through the circuit breaker that feeds your garage 30 amp circuit (that breaker must be "ON"). One limitation that you may not have considered is that since you are only feeding in 120 volts, you will only energize the one side of your main panel that carries the circuit breaker for your garage circuit. Other breakers on that side of the panel will have power, but none of the breakers on the other side of the panel will have it. It will come down to "luck of the draw" as to which other house circuits are on that panel side. That's the advantage of a 240 volt capable auxiliary generator--in that case, with the same back-feed process, you feed the main panel through a 240 volt breaker, which energizes both sides of the panel. In my case, I installed a 240 volt 60 amp sub-panel in my garage for outside power and lights, and that's where I tie in the generator. With the main breakers to my main panel switched OFF, and the 60 amp breaker to my sub-panel switched ON, my main panel has 240 volts back-fed from the sub-panel to all circuits. My generator breaker protects that feed, but in practice, I still keep my high amperage 240 volt breakers (A/C unit, electric dryer, etc) switched OFF to prevent accidental overloads. Even the small 6KW generator carries everything else easily (including my NG central heat blowers), so can remain pretty normal during outages. Last usage was only about a week ago, when we had a 24-hour outage on our rural electric cooperative system, and it was nice to have normal heat and power. In 2002 we had a severe ice storm and our outage stretched to 13 days in our rural area, that's when I first acquired the generator and established the hook-up.
Mike
I found Volkemon's Transfer switch receptacle post. I will look into that. I thank both of you.
About my particular situation. I have a wall outlet like this right by the RV over-head garage door. Now I am thinking I have a 240V receptacle there.
(https://www.askmediy.com/wp-content/uploads/2013/03/50amp_4_wire_906129669.jpg)
Typically when I plug my PC into it, I use an adaptor similar to this.
(https://lh3.googleusercontent.com/proxy/m-090djbzS3RpSLGfvr8u-L8r7_CTI_h78Axza-Wfwes9rNedJwDFMea473BsHzM4WVwpXkZWvLxbTTF0qgA6NlPeg)
If I back-feed 120V-30A from the Onan 4000 into that outlet through such an adaptor, I think I am supplying power to only one of the two hot wires back to the house. Oh well.
Project #1 is to get a 120V-30A receptacle wired off the power transfer switch inside our PC.
It is too bad Onan did not include direct power outlets on the generator like a normal generator has.
-
In the new house I insisted they install a "priority circuit panel". This is a sub panel of the main that has in it all of the circuits that would be run by a generator. Lighting (all LED), freezer, refrigerator and a few plugs here and there.
The panel has a transfer switch so it is either fed from the main panel or a generator input receptacle located outside. The plan is to run that panel from the generator in the cruiser or from a separate generator that can left to run outside and plugged into the outside receptacle. Everything wired to code, inspected and approved.
The problem with using the PC generator is it is 120 only so it will power only one side of the priority circuit panel where a real backup generator would power both. Still it will work and that is what I have in place for now. I may eventually buy a separate generator but its OK for now.
-
1) Flip "OFF" the main house breaker(s) to isolate the house from community power.
""Turn off every small breaker that distributes power throughout the house.""
TURN OFF THE BIG ONES TOO!!! THEY WILL BACKFEED ONE LEG!!!
Did I not cover that one? Or am I missing something I need to think about?
-
If I back-feed 120V-30A from the Onan 4000 into that outlet through such an adapter, I think I am supplying power to only one of the two hot wires back to the house. Oh well.
Ron, back feeding into a house receptacle like that is against code and potentially dangerous. You are feeding into the house wiring and on out into the power company lines. It is 'safe' if you first turn off the main breaker, but consider what happens if you forget to do that? Having a proper transfer switch is really the only way to go. Or just extension cords to key appliances from the generator.
-
If I back-feed 120V-30A from the Onan 4000 into that outlet through such an adapter, I think I am supplying power to only one of the two hot wires back to the house. Oh well.
Ron, back feeding into a house receptacle like that is against code and potentially dangerous. You are feeding into the house wiring and on out into the power company lines. It is 'safe' if you first turn off the main breaker, but consider what happens if you forget to do that? Having a proper transfer switch is really the only way to go. Or just extension cords to key appliances from the generator.
I do realize the importance of killing the main house breakers (200amp service) to isolate the house from the power company power lines. That does require serious discipline.
A power transfer switch associated with the main house is more than I can handle as well as not wanting to compromise my main house by adding an electrical doohickey in there. I was primarily trying to come up with a method to run the house furnace and the only place to easily provide power to it, is through the main panel, gaining other benefits for the fridge and such from that setup.
I suppose I could wire an outlet for the furnace and use an extension cord for it. But I was trying to benefit a bit more.
-
In the new house I insisted they install a "priority circuit panel". This is a sub panel of the main that has in it all of the circuits that would be run by a generator. Lighting (all LED), freezer, refrigerator and a few plugs here and there.
The panel has a transfer switch so it is either fed from the main panel or a generator input receptacle located outside. The plan is to run that panel from the generator in the cruiser or from a separate generator that can left to run outside and plugged into the outside receptacle. Everything wired to code, inspected and approved.
The problem with using the PC generator is it is 120 only so it will power only one side of the priority circuit panel where a real backup generator would power both. Still it will work and that is what I have in place for now. I may eventually buy a separate generator but its OK for now.
John, that is an excellent approach, and a new construction gives you the perfect opportunity to set that up. With my past experience, if I were building new, I would absolutely use a similar approach. Don't know what you can expect in your area regarding power outages, but like any other emergency they normally occur with little warning. Ever since ours was out for thirteen days with that unprecedented ice storm in 2002, I've understood that being prepared ahead of time was the right answer. I was successful in grabbing a generator locally fairly early in that incident, but within a couple of days there were none available in a large radius. Fuel even became a problem because many gas stations didn't have auxiliary power. It's interesting that an adequate generator for occasional emergencies can actually be one of the less expensive items of a quality installation like the one you have. As I mentioned earlier, a 5 or 6 KW 240 volt unit is only about $500, and you can get a larger one to carry everything you possibly need for not too much more. For that outlay, I wouldn't bother to try to harness the Onan in the PC. I keep my emergency generator drained of fuel and under cover, and when I needed it for a 24 hour outage only about a week ago, I pulled it out, checked oil and spark, fueled it up, and it busted off on the first crank after sitting for multiple years. Our electrical service here may be more susceptible to issues than yours, but my vote is to go ahead and set up for it before you need it (just my two cents).
All the best, Mike
-
This is a very interesting subject.
I have wondered if there was an easy way to jury-rig something. In my head, I have wondered if this would "safely" work.
1) Flip "OFF" the main house breaker(s) to isolate the house from community power.
2) Turn off every small breaker that distributes power throughout the house.
3) Plug the PC generator into my 30amp outlet in the garage, but I wonder how to output 110V-30amps direct from the PC generator.
4) Turn on only one house-distribution breaker at any given time.
- Run our gas fired forced-air furnace until the house warms up. The 110V power required would be only for the furnace blower.
- Flip breakers to run the kitchen fridge until it shuts off.
- Flip breakers for other purposes as needed.
Being on a private well that requires 220V, that seems to be a "bust" just like a/c, but everything else just might work. Having our house 100% converted to LED light bulbs throughout should also make a difference. Where we live near Chicago, the focus is more on keeping the house warm in the winter rather than cool in the summer.
Does anyone know how to output 110V-30amp from their PC generator?
Ron,
The short answer to your basic question of "can this safely work" is yes. But it must be done with caution and complete understanding to meet the "safely" criteria. To begin with--it is truly "jury-rigging" as you say; and it is certainly not to code. And any electrical modifications that fall into the category of "jury-rigging" are inherently unsafe and dangerous unless you absolutely know what you are doing. Supplying auxiliary power to your home should absolutely be done through a transfer switch which, if properly installed, will protect your home, your auxiliary power source, and the community power line feeding your home. However I do provide emergency power to my home safely from an auxiliary generator through a back-feed type connection, which is essentially what you describe. In my case, it is a full 240 volts, and I energize my entire main panel. My generator is only about a 6KW unit, so it can't carry my central air conditioning, and I do monitor loads, but everything else is operable.
Your last question of how to output the PC generator is answered in my and especially Volkeman's comments above. You would need to tie in to the transfer switch on your PC to access the full generator output, and wire in a receptacle that will let you connect a 120 volt, 30 amp cord set to your garage outlet. With your house main breakers switched "OFF" to isolate you from community power (absolutely critical, and the first thing to do), you would then back-feed to your main panel through the circuit breaker that feeds your garage 30 amp circuit (that breaker must be "ON"). One limitation that you may not have considered is that since you are only feeding in 120 volts, you will only energize the one side of your main panel that carries the circuit breaker for your garage circuit. Other breakers on that side of the panel will have power, but none of the breakers on the other side of the panel will have it. It will come down to "luck of the draw" as to which other house circuits are on that panel side. That's the advantage of a 240 volt capable auxiliary generator--in that case, with the same back-feed process, you feed the main panel through a 240 volt breaker, which energizes both sides of the panel. In my case, I installed a 240 volt 60 amp sub-panel in my garage for outside power and lights, and that's where I tie in the generator. With the main breakers to my main panel switched OFF, and the 60 amp breaker to my sub-panel switched ON, my main panel has 240 volts back-fed from the sub-panel to all circuits. My generator breaker protects that feed, but in practice, I still keep my high amperage 240 volt breakers (A/C unit, electric dryer, etc) switched OFF to prevent accidental overloads. Even the small 6KW generator carries everything else easily (including my NG central heat blowers), so can remain pretty normal during outages. Last usage was only about a week ago, when we had a 24-hour outage on our rural electric cooperative system, and it was nice to have normal heat and power. In 2002 we had a severe ice storm and our outage stretched to 13 days in our rural area, that's when I first acquired the generator and established the hook-up.
Mike
I found Volkemon's Transfer switch receptacle post. I will look into that. I thank both of you.
About my particular situation. I have a wall outlet like this right by the RV over-head garage door. Now I am thinking I have a 240V receptacle there.
(https://www.askmediy.com/wp-content/uploads/2013/03/50amp_4_wire_906129669.jpg)
Typically when I plug my PC into it, I use an adaptor similar to this.
(https://lh3.googleusercontent.com/proxy/m-090djbzS3RpSLGfvr8u-L8r7_CTI_h78Axza-Wfwes9rNedJwDFMea473BsHzM4WVwpXkZWvLxbTTF0qgA6NlPeg)
If I back-feed 120V-30A from the Onan 4000 into that outlet through such an adaptor, I think I am supplying power to only one of the two hot wires back to the house. Oh well.
Project #1 is to get a 120V-30A receptacle wired off the power transfer switch inside our PC.
It is too bad Onan did not include direct power outlets on the generator like a normal generator has.
Ron, you are correct. Based on your illustration, what you have is a 50 amp, 240/120 volt receptacle in your garage wall. It should be fed from a 240 volt, 50 amp breaker in your main panel. The adapter you are using for your RV is allowing you to pull 120 volt, 30 amp power from that receptacle.
If you were to back-feed your main panel through that receptacle, as you say you would have the option of back-feeding 120 volts from your PC Onan (or other 120 volt source) using that same adapter, or feeding 240 volt power from an auxiliary 240 volt generator directly to the wall receptacle. In either case you would have to have your 200 amp panel mains OFF, and the breaker to that garage receptacle ON. No way can I argue against JATRAX's comments that the back feed approach "is against code and potentially dangerous", or that having a proper transfer switch is the correct way to go. Both statements are certainly true. Doing it the "jury rig" way will definitely work, but there is no margin for error. It depends entirely on the person making the hook-up to not make a mistake that can create a big problem.
If you are seriously considering this, I would definitely consider buying an auxiliary generator capable of 6KW or so minimum output at 240 volts. The $500 or so that you will spend will offset the need to try to modify the PC (not a simple project), and you gain the advantage of having your entire main panel energized instead of only half the circuits (which may not include the ones you most want). I would still keep the 240 volt breakers off, unless you buy a 10-12KW generator set. If your existing receptacle is properly wired (I bet it is), it would support 12KW input (which would be a 50 amp service).
Mike
-
I suppose I could wire an outlet for the furnace and use an extension cord for it.
Ron, honestly the best solution is to do exactly that. If your furnace is hard wired change that to a receptacle and plug it in. When needed unplug from the receptacle and plug into the extension cord. List out the things you need to power: furnace, freezer, refrigerator, etc. Then buy cords that reach from where the generator is set up to the appliances. Put those in a plastic tote with flashlights extra batteries, etc. Now you have an emergency plan.
Ever since ours was out for thirteen days with that unprecedented ice storm in 2002, I've understood that being prepared ahead of time was the right answer.
In 2011 a storm raised the river level and cut the road just down from our house. Our neighbor's house went in the river along with the road. We had no power for 15 days, and no road access for 30 days. Fortunately we did have a generator which was wired up to a simple transfer switch and sub-panel. But carrying 5 gallon cans of diesel in every day for two weeks was an experience I do not want to experience again. We had to rent a car and put it on the other side of the cut and hike out almost a mile every day to get to work, then buy 5 gallons of diesel and hike back in every night.
Being prepared for 2 weeks cut off with no support is now a key priority for us. And a lot of things we did in the new house are focused on that.
-
1) Flip "OFF" the main house breaker(s) to isolate the house from community power.
""Turn off every small breaker that distributes power throughout the house.""
TURN OFF THE BIG ONES TOO!!! THEY WILL BACKFEED ONE LEG!!!
Did I not cover that one? Or am I missing something I need to think about?
You did say flip off the main breaker, but then you specify 'every small breaker...'
(https://i5.walmartimages.com/asr/d8eef512-ec3f-4ab4-be38-87c4cb95b2ce_1.50ba6645611ca65d9018b5612bc10e0d.jpeg)
in the image above, you can see the main breaker at the top, some houses have it separately outside. This indeed should be shut off as you stated.
Then there are the ones that distribute the power through the house. There are five 220V or 'Big Ones' , and fourteen 110V or 'Small ones' on this panel.
If you only turn off the small ones, the big ones will still be making connections from the one leg you have powered. So thats why I was adamant about turning off the big ones as well as the small ones. Hope that makes it a little clearer. As it has been well said now, we are dealing with a rather dangerous way to power a house in emergency situations. I do NOT want anyone following this thread to be mislead and believe they are safe. Abundance of caution, if you will. I would rather have that than have unclear directions that can kill.
*************************************************
Volk,
That's why, in areas where it's available, natural gas is heating is typically significantly cheaper than electric. Certainly here in Oklahoma, and even at the higher prices for NG of today. In small systems (hot water heaters, 30K BTU open flame free-standing heaters, even the 50K BTU dual wall furnace in my grandson's house), there is no electricity used at all. Heat flow is by convection, and in standing pilot systems, a 750 millivolt thermopile heated by the pilot provides all the energy needed to hold in the pilot safety valve and activate the solenoid in the main gas valve as called for by the thermostat. In larger, more sophisticated units, such as my central furnace and 2 Lucky's unit, 120 volts supplies the control systems with the gas valve/thermostat circuit powered by 24 volt transformers, but power draw is still almost negligible. In his case there is no blower, but there are circulating pumps; my unit being forced air and 5 ton A/C uses the same 3/4 HP squirrel cage setup as yours.
Mike
AWESOME! NG is truly a boon to those who can use it. Thank you So much for the explanation Mike.
-
Mike,
You are correct in that it would be ideal if I had a 240V 6K generator, but that deceives the purpose utilizing the PC's 4K generator with a supporting 40 gallon mobile fuel tank.
This may sound even more "Out There", but given my situation, I wonder if making a special cable to provide 120V power to both hot terminals on the 240V garage receptacle, would distribute adequate power through my entire breaker panel, both sides of it.
Mike, Jatrax, Volkemon......
I know, I know, I know....about making sure the main 200amp breaker if "OFF" before doing anything else. I am trying to utilize everything I already have on-hand for a "once-in-15-years" situation.
-
Mike,
You are correct in that it would be ideal if I had a 240V 6K generator, but that deceives the purpose utilizing the PC's 4K generator with a supporting 40 gallon mobile fuel tank.
This may sound even more "Out There", but given my situation, I wonder if making a special cable to provide 120V power to both hot terminals on the 240V garage receptacle, would distribute adequate power through my entire breaker panel, both sides of it.
Mike, Jatrax, Volkemon......
I know, I know, I know....about making sure the main 200amp breaker if "OFF" before doing anything else.
A custom cable will certainly power up both legs of the box.
And I would not normally beat a 'dead horse' but your last statement makes me wonder if I communicated correctly.
I did acknowledge that you are powering off the 'main breaker', 200A in your case. (exactly) In our house, those breakers (2 @ 150A) are located outside near the meters. Our inside panels are NOT like the panel I pictured before. So in our inside boxes, and maybe for others also, there are small and big breakers. And none are the main breaker.
The issue was not specifying to turn off ALL the individual breakers that distributes power throughout the house. Not just '"every small breaker that distributes power throughout the house"" like you said, which would imply that leaving the big 220V breakers right next to them on is OK. I am now guessing that your main house breaker is inside, like the picture I posted before. So for you, there is one BIG breaker, and everything below is 'small' be it 220V or 110V.
Just like in our campers, different people may have different setups in their house. If I am told 'just connect the hose to the camper, turn the valve to the correct position, and your water tank will fill"..... that wont work for me in a 2006, but work fine for another person with a 2013 who is giving the advice. I am merely stuck with no water. No harm done.
With the breakers, should someone have a different setup in their house, NOT turning off the 220V breakers (Only turn off the small ones..) it could lead to damage or possibly injury. I would rather have people think I am 'mansplaining' ( Overexplaining? or insert your preferred term... :) ) than mislead someone with a different setup than others.
I am 99.999999999999999999999999999999999999999999% sure you get it Ron. 2o2 :)(: I think also of the casual reader that is getting information here that may just take words at face value.
This thread has been GREAT for exploring the subject. What fun. Thanks to all.
-
No! No! wiring the onan output to both "hot" terminals will NOT be a good thing! The two lines will be in-phase, not 180 degrees out of phase. So all your 220 "appliances" will be fed 110 (120) and will blow the system!
Volkemon is absolutely correct, all the 220v breakers must be Off!
The main breakers from utility power must also be OFF.
Unless you can feed 2 out of phase lines to your distribution panel (and that is not possible from the RV generator) you must have those 220v breakers off! Before you plug in the generator to the distribution panel.
Then, and only then will it be safe and supply all other breakers with appropriate power.
The generator must be disconnected before any breakers are reset, distribution panel first, then main breakers last.
-
Mike,
You are correct in that it would be ideal if I had a 240V 6K generator, but that deceives the purpose utilizing the PC's 4K generator with a supporting 40 gallon mobile fuel tank.
This may sound even more "Out There", but given my situation, I wonder if making a special cable to provide 120V power to both hot terminals on the 240V garage receptacle, would distribute adequate power through my entire breaker panel, both sides of it.
Mike, Jatrax, Volkemon......
I know, I know, I know....about making sure the main 200amp breaker if "OFF" before doing anything else. I am trying to utilize everything I already have on-hand for a "once-in-15-years" situation.
Ron, I understand the "once-in-15 years" criteria. You've made your point about careful and judicious use of your resources several times before on this forum--nothing wrong with that. Also, various risks are not the same everywhere. It may be that your environment has a relatively stable electrical grid. Sure outages can occur anywhere, but you're not on a rural cooperative in Oklahoma with miles and miles of rural open lines that are annually subject to lightning strikes, tornadoes, and ice storms or snow overloads that can knock power out fairly routinely. What makes perfect sense for me might very well be overkill for you.
In any case, you are thinking "outside the box" with your idea of modifying a cable to power both hot terminals of your 240 volt wall receptacle with a single 120 volt source. I see no reason why it wouldn't work with one critical requirement. All of your 240 volt breakers would have to be switched OFF, and remain OFF (except for the one feeding your garage receptacle, of course). In addition, please confirm that nothing else except that receptacle is fed from that breaker (there should be nothing else--but you never know). The two "hot phases" of the panel are segregated from each other (although they share the common neutral), so for the 120 volt circuits, energizing each one should be like powering each side individually. But every 240 volt breaker combines both of those phases into one feed to whatever uses it, and you can't have that common 120 volts on each side of the 240 volt circuit without potential problems. So, in addition to having the main breaker OFF, you would absolutely have to maintain all of your 240 volt breakers OFF as well (except for the one feeding your garage receptacle). Of course you'll still be limited to 30 amps total of 120 volt power, but it should be available on all of your 120 volt circuits. It would be up to you to carefully manage the total load.
I'm going to repeat my disclaimer that I'm not an electrician, and while my earlier comments detailed things I've personally done and that I know work, I've never tried this particular avenue. In theory I see no reason why it won't function as described.
Mike
-
I wonder if making a special cable to provide 120V power to both hot terminals on the 240V garage receptacle, would distribute adequate power through my entire breaker panel, both sides of it.
Ron, technically what you are describing could be done. But I have to emphasize it would be against code and potentially dangerous. AND, it is not going to power everything in your panel, that load is 200 amps and the generator is providing 20 or maybe 30. Please do not do this.
It would be far cheaper and much less dangerous to simply run extension cords from the generator to the appliances that must be kept going in a once in 15 year event. Redo your furnace connection as described earlier and run cords to the furnace, refrigerator and freezer. Run another to the kitchen and you might be able to run the microwave as well. You can hook all of that up to the external plug on your PC and be safe and within code.
-
I Love you guys!
I greatly appreciate everything shared by all here. What fears me the most is on a very cold night in January, the power will go out and we are watching the temperature drop inside the house and out of desperation, I do something stupid. Jatrax makes an excellent point, just do it the "safe" way and run a standard 120V extension cord from our PC to the furnace system in our house. I would need to setup something in advance at the furnace to accept an external 120V input for that "just-in-case" scenario.
As far my house power panel is concerned, this is it. The top main breaker has "200" molded into the handle.
(https://live.staticflickr.com/65535/50724839811_667e013a93_w.jpg)
The 240V-50 amp breaker pictured here in the garage, is the one unlabeled in position 30/32.
(https://live.staticflickr.com/65535/50724839906_a78e8d0210_m.jpg)
(https://live.staticflickr.com/65535/50724937897_2697020bc9_b.jpg)
From what you are saying, if I try the back-voltage approach at the garage utilizing a single hot wire (not both on the 240V receptacle) only the breakers on the right side will function. If this is true, than the process would be as follows. BUT prior to all this, my PC needs to have a 30A output off the power transfer switch (per Volkemon), and also on hand, a specially made 30A male/male power cord.
0) Back the PC out of the garage per 2 Lucky below. roflol
1) Start the PC generator allowing it to warm up to operating temperature, and turn off all 120V breakers in the PC.
2) At the house breaker panel, turn off every breaker including the main 200A
3) Plug the 30A male/male power cord "FIRST" into the garage 240/50A receptacle through a standard 120V-30A/240V-50A adapter.
4) Plug the male/male power cord "SECOND" into the PC 30A Power-Out located by the power transfer switch.
5) At the house breaker panel, turn on only the 50A breaker that supports the garage.
6) See what happens, listen for voltage humming, electronic smell, etc.
7) Turn on the furnace breaker and see if the furnace kicks on....hopefully it does.
8) Once the house is warmed up and the furnace shuts down, turn off the furnace breaker and turn on the breaker that supports the fridge. If not working (on wrong side of panel #19) power an outlet near by and use power cord to power fridge as needed.
9) In between, and maybe along with keeping the house warm and the fridge cool, maybe we could run some creature comforts through powering up a second breaker. The PC generator will let me know if it's too much to handle.
Under NO circumstances, should a different 240V breaker be flipped on. We are on a private well that utilizes 240V. We would have to live without running water.
-
#1 should be move the PC out of the garage so you don't asphyxiate on CO from the generator. :)(:
-
#1 should be move the PC out of the garage so you don't asphyxiate on CO from the generator. :)(:
Of Coarse! roflol
I added step "0"
-
Ron,
One important correction to your understanding. DonC13 and I identified it in a couple of postings on page 2 of this topic, and I guess you missed the correction.
If you use your planned connection of applying 120 volts through the 30 amp adapter to only one phase of your main panel--it is true that only 1/2 of your 120 volt breakers will be energized. I had originally stated that that would be either the left side or the right side of your main panel breakers.
However, Don reminded me that the internal connectors for the breakers alternate to the left and right sides as you go down the panel. That means that if you energize only one of the two hot connections, instead of ALL the breakers on the left side OR ALL the breakers on the right side being powered with NONE on the opposite side--------in reality the powered breakers will alternate left and right as you come down the panel. A 120 volt breaker on the left will be energized, then--next down--a 120 volt breaker on the right will be energized. The alternate breakers on each side will still be dead. So instead of all your hot breakers being on one side--in reality they will alternate side to side as you come down the panel.
Now, I can't tell you which of the two hot connections in your receptacle connect to which phase/side of the main panel----what I can tell you is that switching to the opposite hot lead will switch the breakers being energized. That means that one hot connection in the plug that goes into the wall receptacle will energize one alternating set of breakers, and changing the hot connection to the other plug lead will energize the opposite alternating set.
Hopefully this is clear as mud, but it's an important change to your understanding of what to expect. Other than that, your listed sequence appears correct.
Mike
-
Mike, I missed that point earlier, and "I Get It" now. That actually makes a lot more sense. I was scratching my head in how 240V worked with my previous understanding.
Going full circle here......
Given my particular situation, If I energized both hot leads in the 240V receptacle in the garage, that would make my entire panel straight 120V, right? As long as all my "other" 240V breakers remain "off", it seems I would do no harm. This way I can selectively turn on the 120V furnace breaker, 120V fridge breaker, and maybe another 120V creature comfort breaker anywhere inside the panel. I would be limited only to what the PC Onan 4000 can output. If I over-load the generator, it would simply trip it's safety mechanism as it has been known to do when running the PC a/c unit, microwave oven, and coffee maker in unison.
Right?
-
Ron...
https://forum.phoenixusarv.com/index.php?topic=4297.msg37657#msg37657
-
Ron...
https://forum.phoenixusarv.com/index.php?topic=4297.msg37657#msg37657
2o2
I get it!
-
Ron,
There are so many things wrong with your plan I'm not even going to list them.
All I will say is that technically what you are planning might work. And if only one tiny thing out of a whole list goes wrong you end up with a range of bad results. Ranging from a blown breaker to starting a fire.
If it was a true emergency and you had no other options or choices yeah, I might try that. But there is a much simpler, safer and to code way of doing it.
it seems I would do no harm.
This phrase just plain sends chills up my spine.
-
Ron,
There are so many things wrong with your plan I'm not even going to list them.
All I will say is that technically what you are planning might work. And if only one tiny thing out of a whole list goes wrong you end up with a range of bad results. Ranging from a blown breaker to starting a fire.
If it was a true emergency and you had no other options or choices yeah, I might try that. But there is a much simpler, safer and to code way of doing it.
it seems I would do no harm.
This phrase just plain sends chills up my spine.
I hope never to have to rely on our generator. That being said, I also hope I never regret not taking your advice.
-
Mike, I missed that point earlier, and "I Get It" now. That actually makes a lot more sense. I was scratching my head in how 240V worked with my previous understanding.
Going full circle here......
Given my particular situation, If I energized both hot leads in the 240V receptacle in the garage, that would make my entire panel straight 120V, right? As long as all my "other" 240V breakers remain "off", it seems I would do no harm. This way I can selectively turn on the 120V furnace breaker, 120V fridge breaker, and maybe another 120V creature comfort breaker anywhere inside the panel. I would be limited only to what the PC Onan 4000 can output. If I over-load the generator, it would simply trip it's safety mechanism as it has been known to do when running the PC a/c unit, microwave oven, and coffee maker in unison.
Right?
Ron, sorry for a late response--had to run to Tulsa today so was away from the computer until this evening.
There are a lot of posted questions that I don't try to address on the forum, but when I do address one (such as 2 Lucky's original post), I feel an obligation to stay in the conversation to the extent I can contribute as long as any questions keep coming. I also feel obligated to try to answer technical issues accurately and straightforward--with my very best knowledge and understanding.
It is obvious that both DonC13 and JATRAX have very strong advice that this particular modification and approach should be avoided. I have read many, many of their posts over the years and respect both of them greatly. I have already said, but will say again, that they are absolutely correct that the whole back-feed approach is not code compliant, and any non-code modifications are inherently risky, because the whole purpose of the NFPA 70 National Electrical Code is to eliminate danger and risk from electrical work. So my response is not to argue or debate the advice they have given, but simply to answer the question you asked as accurately as I can based on how electricity works.
If you energize both hot leads in the 240 volt receptacle in your garage, the 120 volt potential will back-feed from your receptacle on BOTH hot wires that connect through your 50-amp breaker to EACH side of the main panel in your wall. The two separate "hot" copper or aluminum busses in your main panel--that normally each carry 120 volts out of phase with each other--will now each be energized with the same single phase of 120 volt electricity that your generator is providing. Since those two busses in your panel are necessarily isolated and insulated from each other, they essentially then function like two independent busses receiving the same input. Electrically, this condition in itself does not present a problem.
The potential problems ensue with the external connections into or out of the main panel. You already understand that if the panel 200 amp mains are not disconnected, the panel can then back-feed and electrify the lines coming into your home; in addition, if external power is suddenly restored, you then have two separate sources of electricity feeding your panel----it is critical that both circumstances be avoided by always keeping the mains open.
The other issue is with all of the breaker-fed circuits to various places in your home. Since every 120 volt breaker accesses only one side of the panel, both busses being energized do not affect that 120 volt circuit. It simply picks up the 120 volts from it's respective bus just the same as it would if a proper 240 volt source was feeding the panel. In the case of the proper 240 volt source, roughly half the 120 volt breakers would be on a different phase than the other half, but they don't know that--they just see 120 volts.
The potential problem is with the 240 volt breakers (except for your receptacle breaker through which you're back-feeding). The other 240 volt breakers are now energized from both busses---just like they would be from a 240 volt source, EXCEPT those two busses are NOT at different phases, and they do NOT now equal 240 volts across the two hot wires coming out of your 240 breakers to your appliances. That, again, is a critical condition that you absolutely cannot allow to exist. That is why it would be just as crucial (in the case of this type hook-up) that ALL of your 240 volt breakers be kept OFF. As long as the breaker is OFF, the fact that the input to the breaker is incorrect shouldn't be an issue---the two individual circuits through each 240 volt breaker are necessarily isolated and insulated from each other, just like the busses are. If the breaker is switched OFF, there is nowhere for the improper 120 volt potential to go; it simply sits there on the input terminal of the breaker.
There is really no difference here from your necessary action if you were only energizing one side of your wall receptacle with your generator-----since each 240 volt breaker would have power on one lead and not the other, you would still want to keep all of your 240 volt breakers switched OFF, to prevent only 120 volt power from being provided on a single leg of the feed to your 240 volt appliance.
As a last comment I will repeat what I previously said about this: I've never had occasion to personally use this particular approach----but I see no reason why it won't function as described. That is not a recommendation, it's just the technical answer.
Mike
-
That being said, I also hope I never regret not taking your advice.
Ron, if I didn't have a lot of respect for you and your contributions here I would have shut up a long time ago. I'm starting to feel like the guy standing aside and watching as the train wreck occurs.
My house in Oregon was in the national forest at the end of the road as far as power is concerned. We lost power for significant amounts of time (greater than 4 hours) at least once a month and sometimes once a week in the winter. So I have lots and lots of experience with running a house on a generator. There are safer ways to do what you want to do.
Anyway, best of luck and I sincerely hope nothing bad happens.
-
This has been an interesting thread with lots of good info.
But I have to side with jatrax on this one.
One thing that has not been discussed is the common use of multiwire branch circuits in residential wiring.
Not every electrician uses them but most do.
What they are: instead of using say two 14/2 Romex cables to a remote spot in the house for two circuits, they run one 14/3 cable.
They are also widely used in service relocations where you need to get a lot of circuits from point A to point B.
The two hots share one neutral and because they are out of phase the neutral currents cancel each other out.
This saves money on copper and is safe. (until you have a broken neutral)
In the good old days these were wired to regular single pole breakers located next to each other in the panel to get the 240V between hot legs.
More recently the code requires them to be installed onto a double pole breaker.
In your scenario of feeding the entire panel on one 120V 30A generator, both of the hots in the multiwire branch circuits will be in phase with each other.
In this instance the neutral currents ADD. So it would be possible to have up to 30 amps on a neutral wire designed to carry 15 amps. Not safe.
Another thing to consider is even if you only power one side of your garage plug with 120V, you would STILL need to turn off your double pole 240V breakers.
Reason being, if left on you could get a back feed through a 240 volt appliance say a stove or electric water heater element for example, that would effectively put the circuits that you did not intend to feed with 120 V in series with the 240V elements of your appliances. This would provide a lower voltage to your 120V items that your electronics will not like.
One other point to think about is if you were to do something like this, and god forbid something happened to your home (or you) and authorities or even worse you insurance company found a non conforming condition, you could risk losing coverage for damages.
I see you already know the importance of plugging in the garage outlet BEFORE plugging into the generator, but hey we are all getting older and sometimes we forget and having those blades of the male cord end energized and exposed can be a real threat to your health. (and just one more code violation)
WIll it work, yes if you get it right, but there are so many violations that I don't think it is worth the risk.
So like I said, I'm with jatrax on this, if it is not worth the expense of doing a properly wired transfer switch to you then please just run an extension cord to the generator and plug in the appliances you need.
Just my 2 cents.
-
I want to thank Mikeh, Volkeman, and Donc and others for sharing their experience and talent in answering my question correctly in regarding the most important part of the question: to SAFELY supply power from the RV. Electricity is very simply quite complicated, and can kill you.
I don't know how many readers of this forum have looked closely at Jim Godfrey's profile picture, but I have to wonder how he obtained that photo of me as a child....
Be safe out there and seek happiness not only on the Holidays!
Dougn
-
I don't know how many readers of this forum have looked closely at Jim Godfrey's profile picture, but I have to wonder how he obtained that photo of me as a child....
Dougn
roflol And how well it fits this thread....
(https://i.redd.it/y1eam66btu551.jpg)
-
So our first thanksgiving dinner in our first house (1983 I think). Drywall is on but not taped. No covers on the outlets. Not all wiring circuits hooked up. A million other safety issues. But we had a house and no mortgage. It would take 7 more years to finish.
But anyway, Thanksgiving dinner and my wife is doing dinner for both our parents for the first time. We sit down to eat and #1 son (5 at the time I think) did exactly what is shown in that picture. All lights in the house go out. Screaming kid running around in the dark. No one can move because its pitch dark. No cell phones for flashlights in those days. I feel my way along the wall, out of the dining room, through the kitchen to the basement stairs, down the stairs and into the basement, along the wall to the breaker panel and find the breaker by feel.
I was informed that the rest of the wiring would be completed tomorrow or I would be living elsewhere. For some reason my parents in law insisted that covers be put on the receptacles right away too. :)
-
Well, I think everything that can be said on this subject has been except one:
The quickest way to ruin a $2,000 fridge is to run it on a small generator that barely makes enough amperage to handle the load. I learned this the hard way years ago, on my first hurricane after we moved to Houston. I had previously picked up a small generator at Northern Tool that I calculated should have been capable of keeping my fridge and freezer running, plus a fan, a TV, and a lamp. Every time the fridge or freezer would kick on, the generator would bog down, obviously working hard to keep up with the load. In order to stretch our gasoline supply, we'd shut everything off every four hours, and over night. About a week in, the fridge just quit coming on. At that point, we threw in the towel, gave all the meat to the neighbors, and moved in with our San Antonio kids for the duration. The repair bill was about $500 -- more than I paid for the generator.
After that experience, about the only thing I'd try to run off that cranky ONAN in the RV would be the stuff in the RV. If all I had to keep my house from freezing was that generator, I think I'd drain the water lines in the house and move into the RV.
-
Making a plan for a power outage is important I think. Sometimes we worry about things that don't matter, sometimes we forget things that are. But you also need to think about how long an outage you are preparing for and adapt the plan.
1-2 hours: probably not an issue in most homes. Grab a book and snuggle up.
4-8 hours: keeping the house warm enough to be comfortable and not freeze pipes is the priority. Keep power to the furnace, don't worry about anything else.
8 hours plus: Most modern refrigerators / freezers will last close to 8 hours. The new freezer we got states if not opened it will hold temp for 48 hours. After 6 hours though I would start worrying about the refrigerator and freezer. They do not need to run all the time, just long enough to get back to temperature. Here is where a wireless temperature gauge comes in handy so you do not have to open them up to check. I have one on the desk in my office with sensors in each freezer compartment. I can tell at a glance what the temp is and if there is a problem.
Run an extension cord from the generator to each appliance then alternate on until temperature is reached then off for 4 hours or so. Or as long as its comfortable for the furnace. Try very hard not to run anything else when the furnace is on if you have forced air. The fan motor starting will pull the voltage down enough to harm other things if the generator power is marginal. Which it will be if using the generator on the PC.
For lights get a couple LED lanterns. They run on 4 - 6 D cells and will last days if not weeks. We used to keep 2 oil lanterns ready when we were in Oregon but when the LED ones came out we bought 2 and got rid of the oil ones.
If you have a gas hot water tank and are handy rig it up the same as the furnace, wired to a receptacle that you can then unplug and plug it into an extension cord. NOTE this will not work on electric hot water tanks, only the gas ones where the only power needed is for the controls.
-
We never had backup power in Maryland. I found a tip somewhere to know when to throw out the meat in the freezer. NOW while you have power, make ice cubes. Put some in a freezer container and stick it in the middle of the freezer. Check after power outage or trip away from home. If still cubes, good to go. If melted or refrozen as ice puddle, start tossing.
-
We never had backup power in Maryland. I found a tip somewhere to know when to throw out the meat in the freezer. NOW while you have power, make ice cubes. Put some in a freezer container and stick it in the middle of the freezer. Check after power outage or trip away from home. If still cubes, good to go. If melted or refrozen as ice puddle, start tossing.
GREAT advice! (cheer) There is so much here. What a thread! We use a variation for freezer monitoring. I freeze water in a small plastic cup, and put a penny on top, If the penny is sunk in or on the bottom, you know thawing happened.
-
As a follow-up, I had an electrician evaluate my concept, and glad I did. He loved the idea. It was not real complicated, but easily over my pea-brain saw-dust fogged head. He added a GFCI, code for a garage outlet. He also had concerns over the difference in type of ground between home and RV, but it seems to not be an issue. Best of all , he did a clean code-compliant install in a tenth of the time I could have.
I went the simple route I had envisioned, an appliance plug-in from boiler to outlet, easy to swap to extension cord from the RV for generator supplied power for the boiler when needed.
I tested it and it works great off of the generator, but discovered it draws closer to 10 amps with the 50 extension cord, about twice what I had estimated, but still not too much. The zone controller itself pulls almost 4 amps just static.
As long as we are at home when the power goes out....
-
draws closer to 10 amps with the 50 extension cord
Check the gauge on the extension cord. Smaller gauge cords will heat up and as they heat the resistance increases. On short runs or intermittent use that rarely matters. But continuous use over 50 feet, it can be a factor.
Good quality 12 gauge cords are crazy expensive right now but that's what I would use in this situation. Per spec a 14 gauge cord can carry 15 amps but over a large run and continuous use that should be derated putting you close to maximum. A 12 gauge cord can carry 20 amps so even derated you have a comfortable margin.
If you already have a 12 gauge, then never mind........... 2o2
-
Good quality 12 gauge cords are crazy expensive right now but that's what I would use in this situation. Per spec a 14 gauge cord can carry 15 amps but over a large run and continuous use that should be derated putting you close to maximum. A 12 gauge cord can carry 20 amps so even derated you have a comfortable margin.
Sound Advise!
I have two 25 foot long RV 30amp extension cords that I carry in our PC "just-in-case" the power peg is so far away as was the case in Badlands National Park. RV 30amp cords make excellent high-power extension cords for repurposing at home. You only need the appropriate adapters which are nice to carry in your PC as well.
So buy what you need for your PC and repurpose them at home for the rare power outage.
-
Ron , I carry one 25’ RV extension but two? The post at the park you mentioned was 75’ away? What were they thinking
-
The power peg was far. It has been many years since camping in that camp ground. I wonder if we were camped in a non-electric site, but near an electric one. If memory serves me correctly, there was nobody else camping in the entire camp ground at the time. We generally seek a nice view when picking a campsite so I assume that is why we didn't pick an electric site to begin with. It has been too long to remember enough detail.
-
Ron, in any event we’ve found having one Rv ext cord had come in handy more than once. I also carry a 10-12 foot old section of 3/4” garden hose. There’s been times where once parked the sewer connection was a few feet beyond our reach.
Now folks we return you to your regularly Scheduled subject. 😁
-
Apologies if this has been covered, and I missed it. All Onan generators lose output capacity with altitude. The Onan 4000w generator is producing ~3300w at 5500'. Then ~140w loss for every additional 1000'. As was noted by others, a heavier gauge extension cord is a requirement for providing an electrical output any distance from your rig.
Safe travles.
- CD