For the past several weeks we have been discussing a working vocabulary to use when talking about electrical systems. Before we move on to actually using our new vocabulary, it might be a good idea to summarize where we are to this point.
The concepts or vocabulary words we have learned thus far are:
Voltage: the pressure in an electrical system.
Current: the flow in an electrical system
Circuit: the path that electricity takes when the pressure causes electrons to flow
Resistance: any opposition the circuit has to the free flow of electricity.
This is a good beginning because we can now discuss virtually any aspect of a normal or abnormal electrical system and, if we understand the above words, we can understand the discussion.
Jon Vermilye
That is part of what will trip the GFCI. The other factor is that tying the two neutrals together makes the 30 amp side of the service entrance neutral/ground bond look like a neutral/ground fault to the 20A GFCI. Modern GFCIs will trip when detecting a ground/neutral connection after the GFCI.
There is also quite a bit of discussion on the forum about the problems this adapter can cause for the campground’s wiring system. Unless the user knows enough to properly use this adapter it is more trouble than it is worth.
Larry Cad
Dennis, first of all, the adaptor you describe gives you 30 plus 20 amps, for a total of 50 amps. A true 50 amp service for an RV gives you 50 plus 50, for a total of 100 amps.
Second, I have never studied the adaptor you describe and don’t know why it trips the GFCI. I can only speculate: a GFCI outlet monitors neutral current and compares it with the hot current. If the difference exceeds 5 ma. the GFCI trips. I would suppose there is some sort of common neutral wiring in the adaptor which allows some of the 20 amp neutral current to return via the 30 amp neutral wire, thus causing sufficient unbalance to trip the 20 amp GFCI. Don’t know if that is truly what happens, just one guess.
Perhaps someone else has a better idea???
Dennis Carlson
LARRY;
SEVERAL COMPANIES SELL A RV 50 AMP CONNECTOR BOX THAT PLUGS INTO A 30 AMP OUTLET AND A 20 AMP OUTLET COMBINING TO GIVE 50 AMPS BUT THESE UNITS WILL NOT WORK IF THE 20 AMP OUTLET IS A GROUND INTERRUPTOR. WHY DOES THIS SETUP TRIP THE INTERRUPTOR AND IS THERE ANY WAY TO MAKE THIS TYPE OF SYSTEM WORK?
I READ ALL THE TECH BLOGS !