1984 H31 The shorepower connection between the cord and the boat receptical melted together after using a/c for several hours. I finally separated the cord end from the plug and the ground wire got hot and melted the surrounding plastic. I temporarily connected the wires together with wire nuts so as to use air conditioner inside while working. Ran a/c several hours yesterday and then noticed that plastic coating on the wire nut on the ground wire was melted. Have not had a chance to get any voltage or amp readings on anything yet. The a/c is a 16kw Cruisair which draws around 17 amps which has been running fine. Service circuit is 20 amp/120volt. Could this be a bad ground on the boat? Could it be a problem with the electrical service? Any help appreciated.
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Nope....
Good idea, but I remember checking the first time the plug overheated....115 volts. Thanks
Good idea, but I remember checking the first time the plug overheated....115 volts. Thanks
Big Problems
Gary, if I understand you correctly, you are melting the "ground" wire/wire nut. To me that means the green wire, which should not be carrying any current at all! Go to HomeyD or similar and get one of those $5 plug-in circuit testers. It sounds like you could have a wiring feed problem. The neon light pattern will show you what the problem might be, if any. The other possible cause for wiring overheating (assuming as you stated that the load is within parameters) are loose or corroded wire connections at the socket. Remove the receptacle, clean and tighten the wire connections.
Gary, if I understand you correctly, you are melting the "ground" wire/wire nut. To me that means the green wire, which should not be carrying any current at all! Go to HomeyD or similar and get one of those $5 plug-in circuit testers. It sounds like you could have a wiring feed problem. The neon light pattern will show you what the problem might be, if any. The other possible cause for wiring overheating (assuming as you stated that the load is within parameters) are loose or corroded wire connections at the socket. Remove the receptacle, clean and tighten the wire connections.
Dont jury rig the ac.
How far are you from the source. You may not have the current available to run what you have pluged in. Is the ac pluged in directly or do you have it running to your house power system? This could be really a bad situation.
How far are you from the source. You may not have the current available to run what you have pluged in. Is the ac pluged in directly or do you have it running to your house power system? This could be really a bad situation.
To use the proper terminology.....
You are correct Dan, I should have stated the "neutral" wire is overheating, not the ground wire. Also, to set the record straight, the a/c is 16K BTU, not KW (that would be a honkin a/c unit). I went down to the boat today cranked up the a/c unit to get an amperage reading. I was reading about 18 amps which agrees with its specs. Then after about 30 second, it went to 60 amps and tripped the breaker. I called my a/c man and he said that it's probably the water source is clogged. He's probably right as I've never cleaned the water intake. He said to use a wire brush and go to work on the intake hose and screen. Question is....would this be related to the problem of overheating neutral wire? One more thing.....when I separtated the two plugs, the hot wire had gotten pretty hot too. I'll get one of the circuit testers you suggested and try that. Also, I'll check the voltage while the unit is running to ensure I have 115 volts. Ed.....I have a ~25 foot shorepower cord plugged one of those metered dock service units that marinas use for docking slips. Never having a problem before, I assume that the service conductors are adequate. Thanks much......Gary
You are correct Dan, I should have stated the "neutral" wire is overheating, not the ground wire. Also, to set the record straight, the a/c is 16K BTU, not KW (that would be a honkin a/c unit). I went down to the boat today cranked up the a/c unit to get an amperage reading. I was reading about 18 amps which agrees with its specs. Then after about 30 second, it went to 60 amps and tripped the breaker. I called my a/c man and he said that it's probably the water source is clogged. He's probably right as I've never cleaned the water intake. He said to use a wire brush and go to work on the intake hose and screen. Question is....would this be related to the problem of overheating neutral wire? One more thing.....when I separtated the two plugs, the hot wire had gotten pretty hot too. I'll get one of the circuit testers you suggested and try that. Also, I'll check the voltage while the unit is running to ensure I have 115 volts. Ed.....I have a ~25 foot shorepower cord plugged one of those metered dock service units that marinas use for docking slips. Never having a problem before, I assume that the service conductors are adequate. Thanks much......Gary
Gary
Your problem(s) have guys like me hanging on and thinking. Without saying the obvious, like wires should never get hot, at the moment I would only say that you should call for the specs on that AC unit as to the 'high limit' cutout load. Sixty amps seems too high. The high-side (pressure) cutout shouldn't be much more than double the normal load. Oh hell, not even that! Ask too, what your LRA is suppose to be. 'Locked Rotor Amps' is just that. The load you are seeing is close to LRA. Other than that, still scratching my head,,,,
Your problem(s) have guys like me hanging on and thinking. Without saying the obvious, like wires should never get hot, at the moment I would only say that you should call for the specs on that AC unit as to the 'high limit' cutout load. Sixty amps seems too high. The high-side (pressure) cutout shouldn't be much more than double the normal load. Oh hell, not even that! Ask too, what your LRA is suppose to be. 'Locked Rotor Amps' is just that. The load you are seeing is close to LRA. Other than that, still scratching my head,,,,
Just replace the parts.
Gary: We just replaced ours this year too. I think that there is a combination of corrosion and high resistance that causes these problems. Once the resistance goes up, the wires heat and you know the rest of the story. My suggestion is to replace both the receptacle & the cord.
Gary: We just replaced ours this year too. I think that there is a combination of corrosion and high resistance that causes these problems. Once the resistance goes up, the wires heat and you know the rest of the story. My suggestion is to replace both the receptacle & the cord.
This is what I'm thinking....
I think the first thing to do is to clean the water intake hoses/strainer, and see what happens. If the blockage is allowing just enough water to keep it running in a strain, it might cause it to draw more amperage than it should, but not enough to trip the breaker, hence, overheating the wiring. Am I wrong? Thanks, I'll post result.....Gary
I think the first thing to do is to clean the water intake hoses/strainer, and see what happens. If the blockage is allowing just enough water to keep it running in a strain, it might cause it to draw more amperage than it should, but not enough to trip the breaker, hence, overheating the wiring. Am I wrong? Thanks, I'll post result.....Gary
Clogged strainer
Gary, earlier this year, after a storm, I had debris (small pine needles)clog up the strainer on my a/c cooling pump. The a/c breaker on the panel tripped in short order. It takes less than a minute to occur (forgetting to open the thru-hull valve has the same result!). Our a/c unit got very hot when this happened, so I can imagine the current load must spike up to trip the breaker (a thermal magnetic). I still suspect that your hot and neutrals may need tightening. Replacing the cord as suggested may be needed too as the heat in the connector may have softened the plug, leading to a poor contact within the receptacle as well.
Gary, earlier this year, after a storm, I had debris (small pine needles)clog up the strainer on my a/c cooling pump. The a/c breaker on the panel tripped in short order. It takes less than a minute to occur (forgetting to open the thru-hull valve has the same result!). Our a/c unit got very hot when this happened, so I can imagine the current load must spike up to trip the breaker (a thermal magnetic). I still suspect that your hot and neutrals may need tightening. Replacing the cord as suggested may be needed too as the heat in the connector may have softened the plug, leading to a poor contact within the receptacle as well.
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