GFCI tripping problem

[jpc763]

First, sorry for the long post...
I have a 125g Reef Tank in my basement. I have 2 dedicated 15A circuits to the tank area for power. Each circuit has a 15A GFCI recepticle on it.
I have 2 so that if one trips, I don't lose 100% of the power to the tank.
The tank has been set up since February.
In March I had the left side GFCI start tripping due to a faulty skimmer pump. Replacing the pump caused the problem to go away.
Now, twice in the last week, the right side GFCI has tripped. I am not sure what is causing it and thought I would ask for help.
Here is what I have connected...
Left Side Circuit
Vertex IN250 Skimmer with Resun pump
Tunze 6000 (left side)
250w Heater
QT Tank filter, powerhead & light
Right Side Circuit
Rio HF 32 return pump
Tunze 6000 (right side)
3 x 250w MH fixture (2 magnetic ballast, 1 electronic)
2 x 160w VHO fixture
12A powersupply for cooling fan system
Nightlight system
Fuge light
400w Heater
250w Heater
JBJ overflow with pump
Webcam
I moved the return pump and the 400w heater over to the left side after the most recent GFCI fault.
My question is... Any suspects on what is causing it?
Thanks, John

 

[gypsana]

I would get an electrician to your house to check your wiring and circuits. Then can also test how many amps you are pulling. Better to be safe than sorry when it comes to a possible house fire from electrical problems.

 

[al mc]

When I have this type of problem I always suspect one of the heaters first, then powerheads, then pumps. IMHO it usually is the heater.
It is good that you moved some of your electrical draw from the 'right' to the 'left' circuit. The right one still seems to be carrying the bulk of the load though.

 

[bulldog123]

PM wattsupdoc, he is a master electrician.

 

[jimvette1]

Is the GFCI tripping or is the circuit breaker tripping?
This makes a difference.
If the GFCI is tripping you either have a ground fault or a bad GFCI receptacle.
A ground fault can easily be checked by unplugging everything and plug each item back in one at a time.
If it is the breaker that is tripping you probably have an overload.This can be checked using an amprobe on the circuit.You need to balance you load better.
A circuit breaker can also wear out from a constant overload condition.