Originally Posted by cadman99
You are going to find out that GFI circuits in an RV circuit can be real problem. Here are a few GFI things that might help. Possibly the pump in your dehumidifier is the problem.
GFCI breakers are designed to cut the power in the blink of an eye if electrical fluctuations of as little as .005 amperes are detected. Because the GFCI is so sensitive, it is most effective when wired to protect a single location. The more outlets any one GFCI protects, the more susceptible it is to phantom tripping – shutting off power because of tiny, but normal fluctuations in current flow.
GFCI breakers can also be tripped by occurrences such as electrical storms and by moisture from rainfall. It is important that the outlets for the GFCI be kept dry and protected from the elements. Some GFCI’s are more sensitive that others.
It may be that the GFCI is too sensitive. It is normal for continuous running motors, such as pumps, to sometimes have small electrical fluctuations. Sensitive GFCI’s may detect this and falsely trip. You may want to have the electrician try a new GFCI or a different brand of GFCI if this problem persists.
To take this explanation a step further, I believe that some sensitive GFCI can be tripped due to inductance leak in the wiring. In this case the inductance being caused by wires coming too close to each other or a wire coming too close to ground. 2 wires running next to each other even for a short distance can affect each other. 2 wires running next to each other is like an open air transformer. I truly believe this inductance effect can have an effect to a sensitive GFCI and probably the reason for phantom trips like cadman99 talked about. Cadman99 is very correct in saying a GFCI is best for something plugged directly into it.