Shore Power Problem - Ground Fault or Other Issue ?

[DeepFrz]

Try cleaning the contacts on the male terminals with a conductive grease such as no-ox. Leave a little on and work the cable, with no load, on and off a few times. Wipe the terminals and repeat with a light coating of no-ox.

With a good load check the temperatures at both ends of the shore power cable using an infra-red thermometer. You should check the temp regularly. The connection between cable and boat is a big source of trouble.

Better yet, replace the boat end with the smart plug and connector.
http://www.smartplug.com/

[SailFastTri]

Already have a European style connector that seems to have all the advantages of the Smartplug other than the thermostat cut-out. You can buy these on eBay UK for about £4-£16 plus another £7 for shipping to the US. Search for CARAVAN PLUG

[senormechanico]

The voltage sag you are finding isn't critical for a heater, and is in fact probably perfectly normal.
A good comparison is a house with small piping.
When everyone turns on a faucet at the same time, the flow drops at each nozzle.
I wouldn't be surprised if you had similar voltage readings with he heater turned on at the yard's socket.
The actual voltage at different times of the day will fluctuate somewhat depending on local loads.
I remember as a kid, our all tube TV set's picture would get narrow due to the line voltage drop around dinnertime when everyone was using their stoves.

[FlyingCloud1937]

Originally Posted by SailFastTri

Already have a European style connector that seems to have all the advantages of the Smartplug other than the thermostat cut-out. You can buy these on eBay UK for about £4-£16 plus another £7 for shipping to the US. Search for CARAVAN PLUG

Big Worries Mate.

That Euro Plug is not on par with the Smart Plug.

The Euro Plug is dependant on friction fit...which is dependant on temp and corrosion. The locking mech..is on the holder and not the prongs.

The Smart Plug, has locking prong's which aren't friction/temp dependent. The Temp lockout is what makes the plug smart.

Lloyd

[FlyingCloud1937]

Originally Posted by SailFastTri

Don't know. I cut off the ends and re-did the connections in the cable.

Another update -- I made a quick stop at the boat and plugged in with the re-done shore power cable. Everything stayed "up". I would say the problem is solved but it's not... I plugged in an electric heater (1500w) and measured the voltage in another outlet on the same circuit:

1) Fan only -- 121v
2) low heat -- 108v
3) high heat -- 105v

The good news is the heater didn't shut down, but now I'm thinking maybe the outlet in the boat yard is marginal (it is outdoors against a fence). Next time I go back I'll plug the heater right into the boat yard outlet (without going through my boat's shore power) and take measurements on another receptacle in the same quad outlet.

V-Drop....effects the peak SineWave...which effects the RMS voltage,,bc of ohms law...it ripples right on through.

Lloyd

[webejammin]

We went to our boat last week and found the power to my 2 1500 W heaters that had been on low dead, the wind was great so we went out sailing for the day where my wife smelled something burning around the breaker and sure enough the 8 gage ground wire had got so hot the covering had evaporated and the copper wire was getting frayed to no real connection but a little light still came out of the breaker like it was on. After opening up the pannel I replaced the 3 inch ground wire going from the breaker to the ground buss bar and everything works great. I took the heaters off the boat's system and ran a second power cord just for the heaters and made up a 4 GFI plug in a metal box it works great. I don't think most boats are wired heavy enough for elect heaters and will check the back side of the pannel regularly from now on.

[SailFastTri]

Originally Posted by webejammin

We went to our boat last week and found the power to my 2 1500 W heaters that had been on low dead, the wind was great so we went out sailing for the day where my wife smelled something burning around the breaker and sure enough the 8 gage ground wire had got so hot the covering had evaporated and the copper wire was getting frayed to no real connection but a little light still came out of the breaker like it was on. After opening up the pannel I replaced the 3 inch ground wire going from the breaker to the ground buss bar and everything works great. I took the heaters off the boat's system and ran a second power cord just for the heaters and made up a 4 GFI plug in a metal box it works great. I don't think most boats are wired heavy enough for elect heaters and will check the back side of the pannel regularly from now on.

I think something else is wrong. Your ground wire should not be carrying a load unless there is a short to ground somewhere. With shore power removed, you should do a continuity test between the hot, neutral and ground leads. If any are connected you need to trace the short and correct it.

BTW -- 2x 1500 watt heaters would need to be on separate 15 or 20A circuits. If your shorepower is 30A it is maxed out with that load, or close to it if they are on low setting which is probably around 1000w each.

[Seahunter]

This is a neutral issue. "Ground Fault Interupt" is designed to trip if the load is shifted to the ground. Unless the marina has switched a neutral wire to a ground wire somewhere in the circuit then the problem is probably in your cord.

[DeepFrz]

SailFastTri, are you running 115 volts through a 240 volt 16 amp plug? If you are I hope that you are using a 15 amp cct. breaker on the dock.

[Tellie]

Originally Posted by webejammin

We went to our boat last week and found the power to my 2 1500 W heaters that had been on low dead, the wind was great so we went out sailing for the day where my wife smelled something burning around the breaker and sure enough the 8 gage ground wire had got so hot the covering had evaporated and the copper wire was getting frayed to no real connection but a little light still came out of the breaker like it was on. After opening up the pannel I replaced the 3 inch ground wire going from the breaker to the ground buss bar and everything works great. I took the heaters off the boat's system and ran a second power cord just for the heaters and made up a 4 GFI plug in a metal box it works great. I don't think most boats are wired heavy enough for elect heaters and will check the back side of the pannel regularly from now on.

This would seriously worry me.

[Seahunter]

Originally Posted by DeepFrz

SailFastTri, are you running 115 volts through a 240 volt 16 amp plug? If you are I hope that you are using a 15 amp cct. breaker on the dock.

What are you talking about? There's little difference in the AMP, 240V or otherwise. It would be different if he was plugged into a 50Amp plug, with a 30Amp splitter, with a 20AMP 120V adapter; the wiring would light up like an element before the breaker blew if his heater failed.

[davefromoregon]

This thread has been quiet for almost six years so I am comfortable high jacking it.

Today, I was working on my boat and turned everything off to put distilled water in the batteries. Now shorepower does not work. I have checked all of the connections and everything seems like it is flipped as it should be.

Power source on the dock looks good. Neighbors are ok for power.

The breaker at the plug to the boat is ok. But I have no light on my cable to be sure.

The breaker on the power panel is correct but showing no lights.

The outlet breaker is set properly.

I assume this is an idiot thing that I am missing.

Also, the house batteries are working correctly.

[DeepFrz]

Have you actually reset the breakers or just looked at them? They sometimes don't look like they have popped.

Do you have access to a polarity tester or ac multimeter? With one of these you can check the power at each connection to the boat. Just a guess but I would suspect the cable to the boat, especially the boat end.

[davefromoregon]

Originally Posted by DeepFrz

Have you actually reset the breakers or just looked at them? They sometimes don't look like they have popped.

Do you have access to a polarity tester or ac multimeter? With one of these you can check the power at each connection to the boat. Just a guess but I would suspect the cable to the boat, especially the boat end.

I think I have reset everything.

I am looking for a tester in the marina. This is my normal marina in my normal slip.

[davefromoregon]

It was the shore breaker. The Harbormaster pushed things a lot harder than I had.