Cruisers Forum
Main Forum => General Discussion => Topic started by: BruceClerico on July 01, 2021, 08:37:17 am
-
When the campsite offers both 50amp & 30amp hookups, do any of you use the 50amp post with a 50/30 drop down attachment or do you use the 30amp post? Any advantages or disadvantages either way?
Bruce
-
When the campsite offers both 50amp & 30amp hookups, do any of you use the 50amp post with a 50/30 drop down attachment or do you use the 30amp post? Any advantages or disadvantages either way?
Bruce
Assuming you have a 30A service to the coach (Thought you bigguns were 50A for the second AC?) then using the adapter would add another point of possible failure, and add resistance. I have seen the adapters make the cord so far away from the post outlet it droops, and reduces blade contact.
BUT... if you regularly trip the post 30A breaker with your rig, the 30A adapter to 50A outlet would allow you to pull a little more and not trip the 50A breaker. So there is a possible advantage there. But be sure the adapter and cord stay fully seated in their sockets!
-
Bruce,
Volkemon has detailed the only advantage/disadvantage I can think of in this decision, unless one of the post outlets is excessively worn or suspect.
Volk, all Phoenix models (even the "bigguns") are standard with 30A and one A/C, unless the buyer spec'd the 50A option.
Mike
-
Bruce,
Volkemon has detailed the only advantage/disadvantage I can think of in this decision, unless one of the post outlets is excessively worn or suspect.
Volk, all Phoenix models (even the "bigguns") are standard with 30A and one A/C, unless the buyer spec'd the 50A option.
Mike
Gotcha! I had (wrongfully) assumed anything that large had (2) AC units. Florida mindset. THANKS for the correction.
-
No advantage. The 50 amp breaker pedestal is 240v L1 to L2 but an adapter only connects to one side. The main breaker in your RV distribution panel has only a 30a mains breaker.
See below
-
Thanks, Don. Good to know.
Bruce
-
I find the 50amp plug to generally be in better shape, less use than the 30.
-
I find the 50amp plug to generally be in better shape, less use than the 30.
But... You have to add another connection.... The adapter which may or may not have better connectors and can slightly lower the load capacity.
-
If the 50amp connection has two-25amp halves which I understood to be typical, then wouldn't going with the straight 30amp connection provide 5 additional amps?
I always get confused with this topic.
-
If the 50amp connection has two-25amp halves which I understood to be typical, then wouldn't going with the straight 30amp connection provide 5 additional amps?
I always get confused with this topic.
No sir. The 30A has a 120V 'Hot', a Neutral to 'return' the current, and a ground for safety. 3 wires total.
The 50A has (2) 120V 50A 'Hot' wires, a neutral and ground. 4 wires total.
The 30A has ~3600 watts available, and the 50A has ~12,000 watts available, 6000 for each 120V leg (or 'Hot' wire)
When you use the 50 to 30 adapter, only one 'hot' of the 50A service is used, along with the neutral and ground.
Lets say the 30A breaker on the post is old. It has cycled many times, both from being used as a switch and by tripping on overload. Allow also for it living outside in the elements, it has a hard life. This may cause it to trip a little 'earlier' than when new. Say your coach is pulling maximum current when on shore power. Where the 30A breaker in the coach may tolerate being 'on the edge', the worn one on the pole may not. Switching to the 50A adapter, the 50A breaker on the pole (even if worn like the 30) will allow more current to reach the coach. That is the only advantage I could think of in doing so over using a 30A service.
The shore power cabling for both is 10G, so the 'extra' current that the 50A breaker allows to the coach is still in the permissible range for the wire, and will trip before the wiring between the post and coach breaker becomes a safety issue.
-
Here are a few pics of my 50A 'power distribution box' I carry.
(https://live.staticflickr.com/65535/51286981206_b831e7e548_k.jpg)
(https://live.staticflickr.com/65535/51286981366_89809c12c4_k.jpg)
The cord on the bottom is a 6' 50A male cord, and stores inside when traveling. It is currently plugged into the 50A 240V outlet in our garage. The 30A cord exiting right is going to our coach in the driveway.
This allows me to plug in the 30A service for the trailer, and the 30A service for the camper at the same time. (cheer) I also have (2) 20A GFCI outlets for cords. VERY popular with the tenters around me at festivals. When closed, the box is raintight. I have been VERY pleased with this setup, and used it many times.
-
I agree totally with Donc13.
I have made a 50 to 30 adapter using the OTHER leg of the 120. Although I have not had experience with this, I understand that if the campground is nearly full and 'on the edge' of low voltage - and the 50 amp is available you may have better luck with the locked rotor voltage drop on initial A.C. startup.
DonC13 comments?
And I LOVE Volkemon's Craftsman box setup. I need to make one of those!! Volkemon, do you have a picture of the underside? I assume you use different hot legs for each 30 amp plug connection. I can wire it if you don't.
Steve
-
I agree totally with Donc13.
I have made a 50 to 30 adapter using the OTHER leg of the 120. Although I have not had experience with this, I understand that if the campground is nearly full and 'on the edge' of low voltage - and the 50 amp is available you may have better luck with the locked rotor voltage drop on initial A.C. startup.
DonC13 comments?
And I LOVE Volkemon's Craftsman box setup. I need to make one of those!! Volkemon, do you have a picture of the underside? I assume you use different hot legs for each 30 amp plug connection. I can wire it if you don't.
Steve
Thanks Steve!
Here ya go -
(https://live.staticflickr.com/65535/51290181270_e78b43cfce_k.jpg)
All the solid wire jumpers are 10Ga, they look tiny next to the 6GA incoming wire.
Yes, eagle eyed electricians will notice that I should have run the neutral from the duplex outlets directly to the incoming neutral lug on the upper 30A outlet. Mea culpa, but there was not enough room to take (3) 10Ga and the (1) 6Ga into that lug. I SHOULD have made a neutral buss bar.... Being that the whole box wouldnt pass inspection anyway, please allow that one deviation. 2o2 The grounds are OK like that, they should NOT be current carrying wires. (nod)
RE:50A to 30A
FOR THE GUESTS VIEWING THE FORUM: This forum is set up so if you are a guest, you cannot see attachments in posts. >( You cant see the diagram I am referring to from a previous post. The reason you can see the pictures in my (and Ron D's) posts is because we host them 'off site' so non members can see them.
I seem to have a different setup than what DonC13 has. If I am reading his diagram right, the right hand of the diagram is a receptacle, a NEMA 14-50R , like below:
(https://images-na.ssl-images-amazon.com/images/I/61anQcWdc0L._AC_SL1307_.jpg)
So there is 3 outlets in the post? I thought it might be a typo, but a 14-50P would make less sense. The way that diagram shows, there is a 50A 240V receptacle, a 30A 120V receptacle, and 50A receptacle that only gives you the same leg on both L1 and L2. (WH)
I defer to others experience, I am new to RV'ing. I have yet to see this setup on a post in my brief time camping in full hookup. I am pretty sure that an outlet wired like that would not pass inspection nor be allowed.
But if the adapters 'male' side was wired like that, when plugged into a correctly wired 50A outlet you would have a brief 'event' before the breaker tripped from the short. :beg
I have one of these in my 'Shore Power' box -
(https://images-na.ssl-images-amazon.com/images/I/91SvYk4zh4L._AC_SL1500_.jpg)
In the original post, a ""50/30 drop down attachment"" was referenced. Am I correct in thinking this is referring to this item or the dogbone style?
The 'dogbone' style is MUCH better IMO, it avoids the height of the stacked adapter/cord pulling out due to gravity. But I carry this one as an emergency use item for when I might not have packed the 'Power Distribution Toolbox'.
This adapter, (and the dogbone style), are internally wired differently than shown in the diagram. (My artwork is not as good as DonC13's, I am a hack using MS Paint (exactly) )
(https://live.staticflickr.com/65535/51289499488_183c171bc7_b.jpg)
This gives you 120V, 50A service to the camper. The wiring of the adapter can be easily checked with a continuity meter to prove this, both the adapter and meter are on my desk now. :lol I wanted to be SURE before giving electrical advice!! .
The female side is a Nema TT-30R, which is only rated for 30A, but the supply from the 50A outlet in the post is rated and supplies 50A, so it will deliver 50A to the shore power cable. Which as I originally stated, is the only advantage to using a 50 to 30 adapter.
ALL OF THE ABOVE INFORMATION SHOULD BE VERIFIED BY A LICENCED, QUALIFIED ELECTRICIAN BEFORE YOU USE IT TO MAKE ANYTHING. FOR ALL YOU KNOW I AM A DRUNK RHESUS MONKEY WITH A LAPTOP. ALL THIS INFORMATION IS INTENDED FOR SPECULATIVE DISCUSSION ONLY!!
Steve - could you post a diagram of how you have your custom adapter wired? You seemed to agree with DonC13's diagram, and I am obviously missing something. Would NOT be the first time, either. I have learned a lot from other people showing me where I am mistaken. :)(:
-
Volkemon,
Thanks for your Detailed post above. You did exactly what I was thinking of using both legs and simply routing them to different 30 amp outlets. And I'm sure the neutral bus bar may have been the 'electricians' choice. Many extra Kudos for your sharing!
I am not an electrician. I have done some wiring on my 30amp from a re-utilized 230 amp water pump using only one leg for Coach and the other let for shop stuff built in my backyard. Worked great.
I always do some search first to confirm my thoughts.
All 50 to 30 amp dogbones that you buy from the store use Leg 1 of the 50 amp and the Leg 2 is unused. So all I did was to use Leg 2 on the 50 amp side and NOT use Leg 1 [Remember- that is only 30 amps, (not 50)]. That (from what I read) is likely to be less used in a busy campground and therefore have perhaps a few more amps (or higher voltage) available.
Please correct me if I'm off base.
-
Volkemon:
Might want to consider some overcurrent protection for the two GFI's.
I know the 30 amp receptacles on a 50 amp circuit is done all the time (though I don't know why it is allowed) but up to 50 amps on a 120volt extension cord could present a danger.
Probably the easiest way to make it safer would be to stick an inline fuse ahead of the GFIs.
Just my 2 cents.
-
Volkemon:
Might want to consider some overcurrent protection for the two GFI's.
I know the 30 amp receptacles on a 50 amp circuit is done all the time (though I don't know why it is allowed) but up to 50 amps on a 120volt extension cord could present a danger.
Probably the easiest way to make it safer would be to stick an inline fuse ahead of the GFIs.
Just my 2 cents.
Hm! The few parks that we have seen with 50,30 and 20A duplex have all had separate breakers of the appropriate value to control each one. I agree, in a commercial install I would wonder how 50A breaker on a 30A rated service is allowed.
The box isnt in a 'free public use' situation. Should we be using it like that. I would CERTAINLY have it fuse/breaker protected. I agree with the safety concerns you raise. If I can find some 'push button' reset breakers that would fit in the limited free area I have in the box, they might be added.
The box is used outside, and at the base of the post. Placed ~6 feet away from it, and away from any other objects that can be damaged if it 'blows'. Should any of the 'tenters' that use the duplex outlets try to pull 50A , their extension cords will become heater elements then ground display sparklers. :lol The 10Ga solid wire in the box will last longer. Might even take out the duplex outlet. Either way, my camper and trailer will be fine. 2o2
Yes, there are 10Ga extension cords, I have one. But the folks that use those outlets have 16 or 14GA cords as a rule. Maybe 12ga, but generally just smaller ones to run fans and cellphone chargers. And they are cognizant of the limited power use they have, not even hotplates or coffee makers allowed. We have a communal kitchen for that. In a festival environment, tenters around us are generally friends of ours, and VERY grateful to have any power. 'Abuse it and lose it' is the rule. You do NOT want to be tenting in Florida in July with no fan, so the rules are respected.
Worst case, should someone come in the dead of night, plug in their shore power cord with an adapter, and run it to their camper and try to fire up both A/C's and the microwave.... My bet is that the GFCI outlet will fail. They will be on a GFCI, as I am using both 30A for the camper and the cycle hauler. Should the A/C in the camper or trailer stop, believe you me, the occupants will be up and about quickly to see what happened. >(
-
I agree the likelihood of one of the tenters trying to draw that much power is slim but...
Something like this would be cheap and easy insurance.
https://smile.amazon.com/RKURCK-Thermal-Breakers-Overload-Protector/dp/B081PR343M/ref=sr_1_13?dchild=1&keywords=20+amp+120+volt+panel+mounted+fuse&qid=1625497534&sr=8-13
-
Very true. Is my wife messaging you! roflol
And now that I have laughed at it, better get them before the box catches on fire at the next festy. (exactly)
Thanks for the link! :)(: In the cart.
-
I bought a Cable Matters 50 Amp to 30 Amp RV Adapter Splitter from Amazon that I had researched. I did not find out in any comments on Amazon or from the CM website itself how it was wired. Upon receiving the product I tested using continuity on a meter to see if hot leg 1 went to one 30 amp and hot let 2 went to the other 30 amp which is the way Volkemon wired his. My finding was that it did not. BOTH 30 amp receptacles were from hot leg 1. So I am assuming all like splitters will be the same as the one from Amazon. Returned. It looked like a quality product but not worth busting into.
https://www.amazon.com/gp/product/B07WTXWXGB/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
-
I agree totally with Donc13.
I have made a 50 to 30 adapter using the OTHER leg of the 120. Although I have not had experience with this, I understand that if the campground is nearly full and 'on the edge' of low voltage - and the 50 amp is available you may have better luck with the locked rotor voltage drop on initial A.C. startup.
DonC13 comments?
And I LOVE Volkemon's Craftsman box setup. I need to make one of those!! Volkemon, do you have a picture of the underside? I assume you use different hot legs for each 30 amp plug connection. I can wire it if you don't.
Steve
Yes, in a low voltage situation (say 105v AC or lower) you can easily blow the breaker due to A/C compressor 'hard start'. And that's exactly why I added a SoftStartRV to my A/C unit. It reduces startup current for the compressor from 52amp (for 1/2 second) to 24amp (for 1 second). Both are in the normal 'time delay' range for a circuit breaker. But lowering the voltage by 10% (from 120v to 108v = 10% voltage drop) also means a 10% raise in the amperage to maintain the same 'power' and that 52 amp surge will jump to almost 60 amps and pop the breaker.
-
I bought a Cable Matters 50 Amp to 30 Amp RV Adapter Splitter from Amazon that I had researched. I did not find out in any comments on Amazon or from the CM website itself how it was wired. Upon receiving the product I tested using continuity on a meter to see if hot leg 1 went to one 30 amp and hot let 2 went to the other 30 amp which is the way Volkemon wired his. My finding was that it did not. BOTH 30 amp receptacles were from hot leg 1. So I am assuming all like splitters will be the same as the one from Amazon. Returned. It looked like a quality product but not worth busting into.
https://www.amazon.com/gp/product/B07WTXWXGB/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
Wow! I would have thought the same. It does state in the questions and review that it does not, however. I feel a little better about my setup not having fuses...check out this wonder..
https://www.amazon.com/dp/B08NXHHCKG
(https://images-na.ssl-images-amazon.com/images/I/71cS3140HAL._AC_SL1500_.jpg)
""10 AWG all-copper wires,""
So no fuses/ breakers, and it will roast all the way back to the 50A plug. :lol at least they use both legs. 2o2 It may look hokey, but I like my little 'Powerbox' more and more.
-
"Wow! I would have thought the same. It does state in the questions and review that it does not, however. I feel a little better about my setup not having fuses...check out this wonder..
https://www.amazon.com/dp/B08NXHHCKG"
I had ordered that Cable Matters plug BEFORE that Q&A post about it only using one hot leg (Black). I just saw that comment today.
However,
Volkemon, your "wonder" 50 to 20 posted above is the first commercial one using both hot legs. Just a few bucks more ($8), but you can CLEARLY see the hot leg #1 Black and the hot leg #2 Red thru the resin composite. You can also see the common White bus that connects all the 20 amp receptacles. Very cool find!
"So no fuses/ breakers, and it will roast all the way back to the 50A plug." Where do you see the weak point in this. Are you thinking there may be an internal short in the clear resin, or are you thinking someone may try drawing many amps thru one 20amp plug?
I agree Volkemon, your 30amp setup does look safer....
However, here is another choice that at least one reviewer claims it does use both legs. This one is by LeisureCord store. I guess the only way to know is to order one (as I had done above) and check it with a voltmeter to see...
https://www.amazon.com/gp/product/B079NL42ZS/ref=ox_sc_act_title_1?smid=AIVNKK5E0ABND&psc=1
-
All 50a male to 30a female only use one leg of the 50a circuit. Remember, L1 and L2 are each 120v BUT 180 degrees out of phase, so crossing those 2 will be 240v and a huge electric arc!
-
All 50a male to 30a female only use one leg of the 50a circuit. Remember, L1 and L2 are each 120v BUT 180 degrees out of phase, so crossing those 2 will be 240v and a huge electric arc!
TRUE....but we are addressing getting (2) 30A female connections out of (1) 50A female receptacle.
The adapter that would APPEAR to do that only uses one leg, and could have used both. Disappointing.
The adapter even says its 'Rated' to 7200 watts like that's what it gives you... when it can only draw 6000w through one leg. >(
Its pretty easy to get (2) 30A females out of one 50A male without sparks. GA Steve just posted a link to one that (hopefully!) does. ( https://www.amazon.com/gp/product/B079NL42ZS ) I did the same in a 'redneck' manner with my box.
"So no fuses/ breakers, and it will roast all the way back to the 50A plug." Where do you see the weak point in this. Are you thinking there may be an internal short in the clear resin, or are you thinking someone may try drawing many amps thru one 20amp plug?
The latter. Not really a concerning point, however.
Jim Godfrey was correct in pointing out I SHOULD have the breakers before the duplex outlets. I was sorta using the wire as a 'last chance fuse'.
Note how the NEW adapter you found ( https://www.amazon.com/gp/product/B079NL42ZS ) has 10Ga to the junction, then says it has 6Ga to the 50A plug. My box is the same way....the 10Ga wire inside should toast before the 6Ga does damage. So the damage is in the box. (NO testing to confirm, hope I never conduct one! roflol )
The 50A to (4) 20A outlets says it is all 10Ga to the 50A plug. So the 'hot wire' doesnt stop in the junction (in the adapters case), or in the box (in my case) . It will fry all the way up to the plug.
Really not a substantial difference, more an observation. Again, not gonna test. 2o2 Just 'Bench Racing' as they say. :)(:
-
Becha won't find a UL label on this puppy!!!!
???What could go wrong??? ;)
-
""However, here is another choice that at least one Amazon reviewer claims it does use both legs. This one is by LeisureCord store. I guess the only way to know is to order one (as I had done above) and check it with a voltmeter to see...
https://www.amazon.com/gp/product/B079NL42ZS/ref=ox_sc_act_title_1?smid=AIVNKK5E0ABND&psc=1 ""
My post above HAS been ordered and received. I took a meter set on continuity and CONFIRMED Leg 1 goes to one 30 amp, and Leg 2 goes to the other 30 amp. Donc13 states that crossing these 2 will be a huge mistake. These separate 30 amp legs would be used to serve different circuits and would not be combined.
Leisue Cord in California confirmed by phone that Leg 1 did not serve both 30 amp splitters and thus I felt comfortable ordering it. From observation, this cord looks well made and is worth the $40.
Volkemon's box suits his needs better as he has more options and standard 110 outlets which is a benefit.
I would like to test my hypothesis when 50 amps are available and I find low voltage on my meter while using the electrical post 30 amp outlet. I don't want to damage my A.C. trying to run on 105 to 108 volts. So I will see if Leg 2 of the 50amp provides higher voltage.
-
Yes, that is designed to provide 2,totally separate 110v 30a circuits. You NEVER want to plug anything into both 30a plugs that has any chance connecting L1 to L2!
A typical RV park wiring system has 1/2 the 30a pedestal sockets wired to L1 and the other half wired to L2.
Just like your home wiring, 1/2 your circuit breakers are wired to L1 and the other half to L2.
-
Yes, that is designed to provide 2,totally separate 110v 30a circuits. You NEVER want to plug anything into both 30a plugs that has any chance connecting L1 to L2!
A typical RV park wiring system has 1/2 the 30a pedestal sockets wired to L1 and the other half wired to L2.
Just like your home wiring, 1/2 your circuit breakers are wired to L1 and the other half to L2.
Thanks for your informative post DonC. To confirm (from this amateur), if you were to use this in a house, for example, one side would have to only go to breakers wired to Leg 1, and one side could ONLY go to breakers wired to Leg 2. As I understand it, since 1 & 2 are out of phase, a crossover connection down line could result in 220 volts to one side due to the neutral white wire being common to both legs carrying voltage - thereby destroying whatever is connected.
Please elaborate on "out of phase" connections. Thanks for your expertise!
-
Think about two 6v batteries wired in series... B1 negative is connected to B2 positive. So if you measure the voltage from B1 positive to B2 negative, you get 12v. But B1 positive to B1 negative is only 6v. That connection between B1 negative to B2 positive would be considered the neutral wire in an alternating current (AC) system. You don't want to touch B1 positive to B2 negative because you'll get a big spark!
(https://i.pinimg.com/originals/21/bc/c5/21bcc573cb9bc94eb380c6c32ebbefa7.jpg)
So its like a neutral. :beg Really? So if you attach the connecting wire between the two 6V batteries in your camper to the system ground, just like A/C does at the breaker box, all will be well? Please do this in a safe place should you not know the answer. And have a fuse in your test wire.
There are fundamental differences between A/C and DC, and that can make some comparisons difficult.( Like saying cars and trains both have wheels, and both turn corners, so they must steer somewhat similar.).
For anyone else: this borders on a dangerous bit of misinformation. That connector wire, UNLIKE a neutral, is NOT a good ground or current return. Never use it as such. Ever wonder why electric golf carts DO NOT ground the battery pack to the frame? There is good reason.
Please elaborate on "out of phase" connections.
well...you probably wont have two phases in your residential house power anyway...
In the link to Wikipedia, please note this critical line:
""Three-wire single-phase systems, with a single center-tapped transformer giving two live conductors, is a common distribution scheme for residential and small commercial buildings in North America. This arrangement is sometimes incorrectly referred to as "two phase".""
If you accidently 'swap' your hot and neutral in the 110V 30A RV receptacle wiring, the connection between the neutral and ground in the camper should trip the supply breaker to the outlet instantly on plugging it in. Maybe burn the plug and/or receptacle contacts a little too. But it errs on the side of safety.
I can see a scenario where you could have a 50A, 4 lug outlet mis-wired. ESPECIALLY when 'upgrading' an existing 240V 50A 3 wire outlet to a 4 wire receptacle so you can use common adapters for your RV. On a 50A shore power cord, the neutral/ground connection inside should trip the outlet supply breaker. Again, with possible arcing and damage during insertion. With the 'splitter' or adapter, it could give you a working camper, but 120V between the step outside and the ground below. :help Get a severe 'tingle' when touching a metal part on the camper while standing on the ground outside. Or worse.... 240V instead of 120V blowing up devices. AND a 'tingly' camper when touched. >(
This thread has gotten into a potentially dangerous area, PLEASE... DO NOT TAKE THIS INFORMAL DISCUSSION AS QUALIFIED INSTRUCTION. You are dealing with 'invisible' forces that can kill you or others with little or no warning. Electrical code, and inspectors, are there to ensure your safety. The deaths and injuries of others before us has led to the code we have today. Dont join them by ignoring code.
-
I removed the posting
I was not ever suggesting you hook ground to the wire between the two batteries!
I was saying to measure the VOLTAGE between terminals. I never suggested anything else. I was simply comparing the concept.
But you are right, there may well be someone reading this who would try it for some reason or other.. So... Posting gone.
As to "real" vs "center tapped transformer". Every RESIDENTIAL power distribution center that I have tested (5 or so that I have owned over the years) with a dual trace oscilloscope show L1 referenced to neutral and L2 referenced to neutral 180 degrees out of phase.
But yes, that is a result of the electrical properties of center tapped transformers and not a true independent, dual phase system.
Sorry for the scare!