I have a 15 year old house, with a GFI in the basement, yesterday when I came home I found that it had tripped. I took everything off of the circuit and reset it. Within a couple of minutes it tripped again. Why is this happening?
Electrical – GFCI Tripping after 15 years
electricalgfci
Related Solutions
Find the Fault
Firstly, the problem is almost certainly not your GFCI or Circuit breaker.
What has happened is that a fault has developed in your water heater or in your power outlets or someone has hammered a nail into a wall and punctured and shorted a wire. The circuit-breaker has then done the right thing and isolated the circuit to prevent your house burning down in the night whilst you are asleep.
You need to find that fault.
Lights
Your lights are on a separate circuit, that's why they are not affected.
Fuses
Your main distribution board looks like it is fitted with fuse-carriers (not with more modern MCBs or RCBOs). You need to open up the relevant one and check the fuse inside for continuity.
It isn't clear to me how your subsidiary distribution board is connected to the main distribution board. In my part of the world, a subsidiary board is fed from one of the fuses (or MCBs or RCBOs) in the main board - which are labelled to make this clear.
In your case it isn't clear but I'd turn off power to the building and then check fuse 6 since the symbol on that looks a bit like a water heater.
You should only replace this after you found and fixed the fault in your heater room.
It might be that the overload in the room with the heater blew the fuse in the main distribution board as well as tripping the MCB in the subsidiary board (the one with the 0/1 switch). That fuse probably supplies power to the subsidiary board which divides it between the heater and sockets and a couple of other circuits.
If so, the 20A fuse in the main board isn't rated for a full 64A load that your subsidiary board is fused for (20 + 32 + 16 + 16). That doesn't seem right to me.
Glossary
- MCB - Mini Circuit Breaker - has an on-off switch that detects overcurrent faults
- RCBO - Residual Current Breaker with Overload protection - has a reset pushbutton
- GFCI - What Americans call a RCBO (roughly equivalent anyway)
- Fuse - Contains a wire that sacrificially melts to protect you when a fault occurs.
If you have too many receptacles on a 15 amp circuit this would be the issue as an AC unit will draw some current
Best Answer
There are essentially two possible reasons:
It really depends on what's on the circuit to determine if there is a fault somewhere. 15 year old wiring is likely to not be a huge issue. There could be water in a junction box. Simple receptacles and switches aren't too likely to have issues (though it wouldn't hurt to open them to take a look at the connections), but anything with active electronics in it (dimmers, USB chargers, etc) could definitely be the cause. Same goes for other fixtures -- lights, ceiling fans, etc.
You could replace the GFCI and see if it still happens -- if so, there's definitely a fault. If you don't have another GFCI already, this is a somewhat expensive way to test (though if it's fault, you'll have to buy one anyway).
If you happen to have another one you could swap in, that would be a cheap and easy way to test. Swap two, see if it still trips and if the same breaker trips, or the same circuit trips the new breaker.