H356 230V sockets tripping outlet breaker

[tinysailor]

Hi,

We have a 2002 H356 which has recently developed an issue where all 230V breakers work (microwave, water heater, battery charger etc) except for the outlet sockets. As soon as the trip switch in the cabin is flicked to 'on', the main breaker in the lazarette trips as well as the shore power breaker even when there are no devices plugged into the sockets.

There appears to be 2 volts between live and neutral.

I've swapped trips to eliminate the switch itself, however the fault remains.

Looking through the manual (pg 63A-12) there is reference to the GFCI outlet (no idea what the GFCI stands for), which is the first main socket on the ring main which is in close proximity to the switch panel, if anyone can elaborate on the GFCI it would be helpful, because our just looks like a standard socket.

There are no issues on the DC side.

Any help / advice on fault finding would be most appreciated.

Many thanks,

Julian

 

[Bob 04 H260]

Hi Julian, welcome to the forum. In Australia it seems a GFCI is called an RCD does that ring any bells ? Have a look here https://en.m.wikipedia.org/wiki/Residual-current_device for a detailed explanation. It appears you have a short in the outlet circuit. The RCDs you may have seen before were part of the circuit breaker in the panel. It sounds like this one is in the first outlet box and it is used to provide protection for all the outlets daisy-chained down stream.

I would (with the power off ) open the first outlet, remove the RCD. If the main breaker still trips there is a short between the first outlet and the breaker panel. If it does not then do a resistance measurement of the outlets downstream from the RCD if there is no short there replace the RCD.

Good luck, Bob

 

[RoyS]

GFCI is a ground fault circuit interrupter. That device measures current imbalance between the hot and ground wires, which indicates current leakage on one or the other. That, however, is probably not your problem. You appear to have a short circuit which is tripping your upstream circuit breakers. Start troubleshooting by turning off all 120 and 240 Volt circuit breakers. Restore power. Turn your breakers on one at a time until an upstream breaker trips. This will be either the individual circuit breaker, the main, or the breaker ahead of the shore power cord on the dock. When you have identified the particular breaker on your boat that contains the short then determine all of the devices on that one circuit and break the circuit up into pieces until you have isolated the short. This is done by disconnecting some of the circuit and then turning the power on until the breakers hold. Your short is in the remaining part of he circuit hat is disconnected. It is most likely at a device which experiences some manual operations such as an outlet or a switch. Good hunting.

 

[Jerry Clark H356 SV Persi]

It is not uncommon to trip the lazarette breaker if you have HVAC, the water heater on, and try to microwave something if you have other items plugged in if you are only using only one cord and paralleling the breakers. Sounds like you have more of a problem than that, but just in case, and trying the simple approach first, see if turning off the water heater makes any difference. I turn the water heater off when using the microwave, then after use, turn back on. I have a 2003 H356 and only plug in one cord to the dock. When on generator (5KW Northern Lights) I don't have the problem.

 

[tinysailor]

Many thanks for all your replies. Here's an update....

I can confirm that it was only the sockets on the 230Vs that wouldn't work. The fault didn't affect any other 230V system on board.

After separating all the live feeds and returns in the first double socket on the ring main, the RCD stopped tripping. A voltage meter was used to identify the 230V supply and return positive wires. The 2 live supply wires didn't cause the RCD to trip, it was one of the return wires. The functioning wires which were fault free were then reconnected to the double socket and the rest of the sockets on the ring main worked. The faulty return supply wire was left disconnected and made electrically safe for now until time permits to trace the run of the faulty wire. I'm happy with the outcome as it meant not having to pull the boat apart and all sockets now work. We still haven't ascertained the root cause.

Many thanks,

Julian