This winter the power management system on our PC was shutting down several times an hour because of low incoming voltage. I contacted the park office and they sent over a repairman to investigate the problem. He found the 30AMP breaker was burnt and replaced it. Within an hour, we had another failure. Not wanting to live with these constant power interruptions, I tried several different things but I kept getting the same results. Finally, I plugged the PC into the 20 AMP service and the power stabilized and everything ran great but I was limited in what I could run simultaneously.
I had the repairman return and do more testing. This time he measured the voltages and found the voltage on phase 1 was at 115 VAC and fluctuating but the voltage on phase 2 was at 119VAC and very solid. The repairman then opened the pedestal and moved the 30AMP breaker to phase 2 and for the next 3 weeks and we had no problems.
This gave me a chance to get a good look inside a typical 50/30/20 AMP RV Service pedestal to see how they were constructed and wired. The most obvious thing I saw was that the 50AMP service was in fact two separate 50 AMP legs or phases (phase 1 and phase 2). After doing some research it appears that the manufacturer for these pedestals typically prewires all 30 AMP breakers to phase 1 and all 20AMP breakers to phase 2. It seems when the campgrounds receive these pedestals they leave the prewiring as is, i.e. all 30AMP RV's are connected to phase 1, all 50AMPS RV's are connected to both phase 1 and phase 2 and tent sites are connected to phase 2. If an RV park has a good electrician they might change this configuration to better balance the load between the two phases.
I now concluded that the best thing for me to do when phase 1 power at 30AMPS is not stable (especially in a crowded park with numerous ACs running) would be to connect to phase 2 power at 30AMPs. This would be possible if a 50AMP to 30AMP converter were to connect the 50 AMP phase 2 hot lead to the 30AMP hot lead. I checked my 50AMP to 30AMP converter to see how it was wired and as I suspected the 30AMP receptacle was connected to phase 1. This explains why using my adaptor and connecting it to the 50AMP breaker did not improve the electric service. I looked online to see if I could purchase an adapter that was wired for phase 2 but could not find one.
Unable to find a 50AMP to 30AMP converter that connected to phase 2, I decided to find the parts and make one myself. The assembly was very simple and straight forward. The first thing I did was to cut back, cap and secure the black hot lead (phase 1 ) from the 50AMP cable. I then connected the red hot lead (phase 2) from the 50AMP cable to the hot terminal on the 30AMP receptacle. Then I connected the common (white lead) and the ground (green lead) to the corresponding terminals on the 30AMP receptacle. The final product has not been tested yet but I am confident it will work just fine. I will post an update after we return from our next trip.
Here is a list of the parts I used:
http://www.amazon.com/gp/product/B00BHGXYUE?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00http://www.amazon.com/gp/product/B00192MU2Y?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00Barry
