30 amp is really 20amp

j-d wrote:
First, Debbie, WELCOME!
People often "say" things with their fingertips that the rest of their senses like sight and sound wouldn't allow.
V*A=W, true enough. Problem is, appliances etc. want W, so if V goes down, A actually goes UP and A is a major cause of heat.
I just got back from a state park. Park wasn't near full, voltage started around that 118, dropped to 115, then 108, 105, caught it just under 100. Breakers tripping in the Motorhome. This is a 30A coach with 15K A/C. This was happening with only A/C and Convertor. Debbie, one of your 120VAC breakers should be Converter, but probably other things on it that you don't want to power off for long. Still, you could do a test.
So, I complain to the Park, and they send their maintenance man over. Told me he's replaced all the pedestal breakers and outlets. I said I noticed that, my problem was that my A/C was tripping the 20A breaker in the coach and sometimes both the 20A A/C breaker and the 30A main. (that can happen because one breaker heats up the other - I had a small fan blowing on the breaker panel!) Maintenance guy says they have a capital budget request, not funded, to pull all new power service in the campground, about 40 sites. But meanwhile, we were on a loop with 30A breakers and outlets. 10 sites in that loop, powered from a loop with a single One Hundred Amp Fuse! So, 30A "service" that's more like 10A, 100A source divided by possibly 10 users.
So Debbie, YES. Keep coming back.

As I have said before, I am really surprised Darwin hasn't weeded out all the incorrect electrical information posted on these forums. Surely some of these people are due to be electrocuted for messing with things they obviously have no clue about.
If you found a 100 Amp breaker serving the line, it is almost assuredly a DOUBLE POLE, 100 amp breaker, meaning there is 200 amps of service available on the line (2 x 100). Now the NEC (National Electrical Code) uses a formula to determine how many 30 amp RV pedestals can be served by a single 100 amp service. I don't have the calculation available at my fingertips, but it is more than the 200 amps that are available from the service. You find the same thing if you go to your electrical panel in your house and add up the all the breakers. Their value will far exceed the 200 amps your service is called and will likely exceed the actual 400 amps (again two lines of 200 amp service), especially if you double up the ratings of all the double pole breakers since they can deliver that stated amperage through both legs to the appliance they serve.
Voltage drop due to overloading lines can surely happen, but it is not a symptom of having 20 amp instead of 30 amp service.