Starboard 120v Circuit Dead But Breaker Not Tripped

[johngalt]

Good morning all. Yesterday I developed an electrical problem on my 1988 52C. While replacing an AC overhead light in the forward stateroom my starboard circuit ceased working. The circuit was fine and I replaced the light with the breaker on but the light switch in the stateroom off. After wiring light I went to test light before installing in ceiling and found that entire starboard circuit is now dead yet breaker is still hot. Disconnected new light , swapped breakers and still all dead. Said circuit runs from salon outlet to master stateroom light/outlets to master head light/fan/GFI to forward stateroom lights/receps. All dead. Any ideas on what the problem could be would be greatly appreciated. Thanks , Bruce

 

[Finalee]

I would take a close look at the gfi. If its old replace it. It could take the circuit down. Its designed to do so.

 

[sgharford]

My boat /electrical panel is older, but may be similar problem with magnetic trip circuit breakers. Seems after some time (30 - 40 years or so) they go bad. They test well when you put voltage meter on output leg, but moment you put a load on it you get nothing. I would jumper the output leg of circuit breaker in question to output leg of other nearby similar sized circuit breaker (I have 4' long 10 awg wire with alligator clips on each end for just such occasions) and see if that does it. 3 out 4 times (and bout 5 circuit breakers over 10 years) it was circuit breaker that went bad. Good Luck and look forward to seeing you next month!

 

[johngalt]

Thanks gents.

SGHarford , I swapped the feed with another working 20amp circuit breaker and that did not produce any change.

Finalee , Can a bad GFI in the middle of the circuit cause even the upstream receps/switches to be dead? I was under the impression that if the GFI was bad that only those items downstream of the bad GFI would be dead. Pushing the test button on the GFI in master head does nothing. Is that because there is no power to it or because it is bad?


Thanks , Bruce

 

[GJH]

What's upstream of that circuit? Have you checked it all the way back to the source?

 

[racclarkson@gmail.com]

Good morning all. Yesterday I developed an electrical problem on my 1988 52C. While replacing an AC overhead light in the forward stateroom my starboard circuit ceased working. The circuit was fine and I replaced the light with the breaker on but the light switch in the stateroom off. After wiring light I went to test light before installing in ceiling and found that entire starboard circuit is now dead yet breaker is still hot. Disconnected new light , swapped breakers and still all dead. Said circuit runs from salon outlet to master stateroom light/outlets to master head light/fan/GFI to forward stateroom lights/receps. All dead. Any ideas on what the problem could be would be greatly appreciated. Thanks , Bruce

Look for a hidden GFI added by a PO. I'd start close to the panel. That's exactly what happened to me one time.

 

[Finalee]

Thanks gents.

SGHarford , I swapped the feed with another working 20amp circuit breaker and that did not produce any change.

Finalee , Can a bad GFI in the middle of the circuit cause even the upstream receps/switches to be dead? I was under the impression that if the GFI was bad that only those items downstream of the bad GFI would be dead. Pushing the test button on the GFI in master head does nothing. Is that because there is no power to it or because it is bad?


Thanks , Bruce

Short answer is yes. GFI outlets are cheap. Turn off all power before replacing.

 

[johngalt]

Thanks to all. I've been away all day and had no time to pursue the diagnostics but one thing that I have found is that the recepticle in the salon that is nearest to the panel and that I assumed was the very first device of the circuit may , in fact , be the last. There is only one set of wires in that outlet and so would seem to indicate that it is the furthest most downstream device instead of the most upstream. An electrician friend of mine suggested that the builders (Hatteras) may well have run the feed up to the forward V-berth and started back from there. That is my next area of exploration.

The V-berth has a switch , two overhead lights and two recepticles , one of which is fed by starboard power circuit and the other is on the port circuit which is active. Not being an electrician I can only guess that if my friend is right and the circuit starts in the forward stateroom , would the light switch itself be the furthest upstream device with power going from it to the lone recepticle and the overhead lights ? The light switch is my next target.

Bruce

 

[Reefgeorge]

GFI receptacles can act goofy when they are failing and not make any sense.

George

 

[johngalt]

GFI receptacles can act goofy when they are failing and not make any sense.

George

Does that mean that a faulty GFI in the middle of a circuit could kill the juice both upstream and down without tripping the breaker?

 

[Reefgeorge]

Does that mean that a faulty GFI in the middle of a circuit could kill the juice both upstream and down without tripping the breaker?

I dont think so. I think that either your main breaker has failed without tripping or the GFI is the beginning of the branch even if it does not make physical sense. Do you have power into the main breaker and no power out of the main breaker?

George

 

[johngalt]

I dont think so. I think that either your main breaker has failed without tripping or the GFI is the beginning of the branch even if it does not make physical sense. Do you have power into the main breaker and no power out of the main breaker?

George

I have power on both sides of the breaker and switching the main circuit feed to another 20 amp circuit breaker yields the same results. The schematic of the electrical system does show a terminal block in the master closet that backs up to the master head so it is conceivable that you are correct in thinking that perhaps the GFI is the first device of the circuit. I will also explore that possibility. Thank you for the idea.

 

[Reefgeorge]

Does the line side of the GFI breaker have power but the load side does not?

George

 

[Briankinley2004]

Sounds like a loose connection in a junction or fixture box somewhere

 

[johngalt]

Have now replaced light switch in forward stateroom and GFI receptacle in Master head and still no power anywhere on starboard circuit. The electrical plan shows a terminal block buried behind the paneling inside the master stateroom closet. Could that be a potential source of the problem? At this point I am totally exasperated. I'm trying to get boat ready for summer season and after a very late spring start I really cannot afford to keep wasting hours in exploratory electrical work. Unfortunately I live in a vacation home paradise and all of my electrician friends are also facing summer deadlines of their own. Any more ideas from fellow forum members are much appreciated.

 

[racclarkson@gmail.com]

Have now replaced light switch in forward stateroom and GFI receptacle in Master head and still no power anywhere on starboard circuit. The electrical plan shows a terminal block buried behind the paneling inside the master stateroom closet. Could that be a potential source of the problem? At this point I am totally exasperated. I'm trying to get boat ready for summer season and after a very late spring start I really cannot afford to keep wasting hours in exploratory electrical work. Unfortunately I live in a vacation home paradise and all of my electrician friends are also facing summer deadlines of their own. Any more ideas from fellow forum members are much appreciated.

Still suggest looking for added GFI after the breaker probably near panel. I'm not talking about a receptacle.

 

[MadHatter53]

If everything worked before you did the light I would start there. It's easy to overlook something like broken wire or something not connected right. Using a multimeter will take you to your trouble when used correctly.

 

[Briankinley2004]

If everything worked before you did the light I would start there. It's easy to overlook something like broken wire or something not connected right. Using a multimeter will take you to your trouble when used correctly.

I agree with this. It is usually something simple. However if its not you may have to get an ohm meter out and check continuity from breaker to each box until you find what wire goes where to isolate the problem

 

[johngalt]

Thank you all. The problem is solved. My electrician finally freed himself up for an hour and with a toner we discovered that , contrary to the factory wiring diagrams , the GFI in the galley which continued to work was in fact the culprit. Changed that out and now all is back to normal. The original plan showed two outlets in the salon while in reality there was only one. The second one had been placed in the galley above my icemaker and while it stayed hot nothing else did. The toner brought us to it and when we replaced it the rest of the circuit came back online. Mystery solved. Thank you for all of your input.