Hello everyone... So I have a question for any of you electrical gurus who might be out there. On New Years Eve (around 9:00pm to be exact) I noticed a small bit of smoke coming from behind my electrical panel on my 340 Hunter (2000 model). After a short moment of disbelief I disengaged all power and opened up the electrical panel to investigate. The source of the smoke was a wire coming off my main AC breaker switch which runs to what I assume is my positive power bus on the AC side of my electrical panel (the wire is white and runs to a bus with a lot of other white wires running to it... I think this means it's a positive bus but I'm no electrician). Anyway the source of confusion is why the wire fried... nothing else around it fried, and I have since replaced it with a heavy 4-gauge wire (the original white wire was 8 gauge) to prevent problems in the future. At the time the wire caught fire I was running a space heater on the boat, my computer, a 32-inch plasma TV, and perhaps a few minor items like a cell phone recharger. My first assumption is that the main power breaker is bad and should be replaced, and that it fried because I was pulling too much power. However when I overload the system (i.e. run some combination like the space heater and to toaster oven at the same time) the "outlet" breaker always trips... (and after repairing the system I tested the outlet breaker again and it still works) so it seems unlikely that I was pulling too much current at the time of the fire. Basically what I'm hoping someone might help me figure out is two things: 1) Any ideas about what might have caused the fire, and if the main power breaker might be involved. 2) If I need to replace the main power breaker where I might get a new one that matches with the factory original Hunter electrical panel. Thanks everyone for taking the time to read this rather long post. -Levin
- Status
that 32" plasma can draw allot of juice
If you want a low wattage TV, you need a LCD. Is that a desktop PC? It can draw a bunch of power too. The space heater is normaly 750 or 1400 watts, the plasma can be as high as 1500 watts, and the computer (desktop) average draw is around 150-400 watts. Thats 25 amps right there.
If you want a low wattage TV, you need a LCD. Is that a desktop PC? It can draw a bunch of power too. The space heater is normaly 750 or 1400 watts, the plasma can be as high as 1500 watts, and the computer (desktop) average draw is around 150-400 watts. Thats 25 amps right there.
White is neutral
black is positive, green's ground. It sounds very much like you simply had a bad connection, either to the neutral bus or between the wire and the connector itself. While you say you're no electrician, you sure got the nomenclature right, so keep learning about electrical stuff on boats, it's not too hard given your head start.
Most electrical books will suggest: trace your wiring, draw it, if you don't have the manual, and understand it. If your breaker didn't trip, I'm not sure why this would be a question. Replacement of breakers is simple: West Marine or Anchor.com,or Cole Hersee. Take a look in any marine electrical catalog and you'll see who makes the marine equivalent equipment. Stu
black is positive, green's ground. It sounds very much like you simply had a bad connection, either to the neutral bus or between the wire and the connector itself. While you say you're no electrician, you sure got the nomenclature right, so keep learning about electrical stuff on boats, it's not too hard given your head start.
Most electrical books will suggest: trace your wiring, draw it, if you don't have the manual, and understand it. If your breaker didn't trip, I'm not sure why this would be a question. Replacement of breakers is simple: West Marine or Anchor.com,or Cole Hersee. Take a look in any marine electrical catalog and you'll see who makes the marine equivalent equipment. StuBoat Burn
Levin, This is not only tough to diagnose 'over the phone' but also dangerous. You indeed have a problem, take survival action on this one, call Kells Chritian @ 619-223-7380 he is right there on Shelter Island, and can diagnose your problem. Get yourself a good electrical tester, it can switch from 12 DC to 120 AC volts, and you can see which is positive or negative in the future, but call a pro on this one. Good luck.
Levin, This is not only tough to diagnose 'over the phone' but also dangerous. You indeed have a problem, take survival action on this one, call Kells Chritian @ 619-223-7380 he is right there on Shelter Island, and can diagnose your problem. Get yourself a good electrical tester, it can switch from 12 DC to 120 AC volts, and you can see which is positive or negative in the future, but call a pro on this one. Good luck.
In AC electrical
circuits the white wire is always neutral. There is no positive and negative in an AC system. It is pretty clear that you overloaded the neutral but I am not able to say why. An 8Gauge copper conductor is rated for forty amps. Check the rating of the main breaker and also of your shore power supply cable. If I am reading your post correctly the main breaker has been replaced and may be over rated for the rest of the system. Check the name plate power requirements for every devise that you have on board and add up the list of loads. You didn't say what size your space heater is but from the inventory that you mentioned you have the potential of drawing more than forty amps.
circuits the white wire is always neutral. There is no positive and negative in an AC system. It is pretty clear that you overloaded the neutral but I am not able to say why. An 8Gauge copper conductor is rated for forty amps. Check the rating of the main breaker and also of your shore power supply cable. If I am reading your post correctly the main breaker has been replaced and may be over rated for the rest of the system. Check the name plate power requirements for every devise that you have on board and add up the list of loads. You didn't say what size your space heater is but from the inventory that you mentioned you have the potential of drawing more than forty amps.
Two things can cause a fire.
Either the current exceeded the capcity of the wire or the resistance of the wire plus connection increased. This can be caused by a corroded connection, loose connection or corrosion in the wire. The wire issue will not kick a breaker because the total current hasn't increased.
Either the current exceeded the capcity of the wire or the resistance of the wire plus connection increased. This can be caused by a corroded connection, loose connection or corrosion in the wire. The wire issue will not kick a breaker because the total current hasn't increased.
Agree with all, but second Capt. Ron
Don't mess around, unless you have great insurance and your neighbors want new boats too The space heater worries me. While breaker and wire size might be adequate, that assumes everything is still 100% even after 5 years in a corrosive environment. Not likely. BTW, kudos to you, Levin, for the detailed post ;D Cheers, Bob s/v X SAIL R 8
Don't mess around, unless you have great insurance and your neighbors want new boats too
The space heater worries me. While breaker and wire size might be adequate, that assumes everything is still 100% even after 5 years in a corrosive environment. Not likely. BTW, kudos to you, Levin, for the detailed post ;D Cheers, Bob s/v X SAIL R 8Breaker on Hot side
Breakers are normally on the hot side (black wire). I suspect that somewhere you chaffed the white (neautral) some where.
Breakers are normally on the hot side (black wire). I suspect that somewhere you chaffed the white (neautral) some where.
Some things to look at
there is a black wire which comes from the main breaker and goes to the other smaller breakers. Is it ok or was it overheating too? It may be difficult to tell if the black wire has overheated since it is already black. The insulation will get brittle when that happens so look for that too. If it is ok, the problem was likely a poor connection (bad crimp or loose screw) or broken strands of wires in the white wire. You can peel off or break off the insulation on the original wire and see what the wires look like inside. If there are no obvious breaks, look for the hottest location and see what you can find. You should not need to replace this wire with a larger wire. That is akin to putting a penny in the old screw in style fuse box. It is ok to replace the wire with a larger one but that will just move the problem to another section of the circuit if the new wire doesn't fix the original problem. If the black wire has overheated as well, you were probably overloading the panel and should check or replace the main breaker and replace the black wire as well.
there is a black wire which comes from the main breaker and goes to the other smaller breakers. Is it ok or was it overheating too? It may be difficult to tell if the black wire has overheated since it is already black. The insulation will get brittle when that happens so look for that too. If it is ok, the problem was likely a poor connection (bad crimp or loose screw) or broken strands of wires in the white wire. You can peel off or break off the insulation on the original wire and see what the wires look like inside. If there are no obvious breaks, look for the hottest location and see what you can find. You should not need to replace this wire with a larger wire. That is akin to putting a penny in the old screw in style fuse box. It is ok to replace the wire with a larger one but that will just move the problem to another section of the circuit if the new wire doesn't fix the original problem. If the black wire has overheated as well, you were probably overloading the panel and should check or replace the main breaker and replace the black wire as well.
All good advice Levin.
But the part about polarity only should refer to DC. So how's school going? And what the hell are you needing a space heater for. Is San Diego weather bad too? Oh, get the white wire out of the trash if that's where you put it. Show it to the electrician. Don't mess with this stuff. It's simple and easy to learn. But until you learn it, keep your smoke detector battery fresh. And the biggest problem you have is that Plasma TV. Send it up here. I'll take the risk!
But the part about polarity only should refer to DC. So how's school going? And what the hell are you needing a space heater for. Is San Diego weather bad too? Oh, get the white wire out of the trash if that's where you put it. Show it to the electrician. Don't mess with this stuff. It's simple and easy to learn. But until you learn it, keep your smoke detector battery fresh. And the biggest problem you have is that Plasma TV. Send it up here. I'll take the risk!
With tongue firmly in cheek
I think that I have figured out your problem. You let the puff of smoke out. With all systems electrical a puff of smoke is built in by the manufacturer. If you let that puff of smoke out you need to call a specialist that knows how to install a replacement puff of smoke. Then the system will function without problems until someone plugs in the wrong combination of appliances and lets the puff of smoke out again. The circuit breakers are designed to limit the size of the puff of smoke because if the puff of smoke is too large it infects nearby non-electrical systems and causes them to also let the puff of smoke out. When the puffs of smoke get too large it is called fire. Now fire makes very large puffs of smoke.
I think that I have figured out your problem. You let the puff of smoke out. With all systems electrical a puff of smoke is built in by the manufacturer. If you let that puff of smoke out you need to call a specialist that knows how to install a replacement puff of smoke. Then the system will function without problems until someone plugs in the wrong combination of appliances and lets the puff of smoke out again. The circuit breakers are designed to limit the size of the puff of smoke because if the puff of smoke is too large it infects nearby non-electrical systems and causes them to also let the puff of smoke out. When the puffs of smoke get too large it is called fire. Now fire makes very large puffs of smoke.
Thanks to all
Thanks everyone for all the quick replies. When I inspected the white wire I now remember that I saw what I believed was the smallest amount of corrosion on the wire (something that looked akin to green algae like growth on one side). It didn't look like it had spread that far on the wire, but it sounds like even a slight bit of this could have caused the "puff of smoke" that broke my electrical system. I have tried it now under many configurations, running everything I can think of running and so far no more problems... and when I do overload the system the outlet breaker always trips. Still I think I will get an electricians second opinion on this one (Thanks Capt. Ron, do you know if he makes trips out to Coronado because that's where I'm located). Again thanks to everyone for the help and advice. -Levin P.S. For Fred: School's going great, just defended the dissertation about a month ago and should be finished with internship in July... all looking good for an August graduation
Thanks everyone for all the quick replies. When I inspected the white wire I now remember that I saw what I believed was the smallest amount of corrosion on the wire (something that looked akin to green algae like growth on one side). It didn't look like it had spread that far on the wire, but it sounds like even a slight bit of this could have caused the "puff of smoke" that broke my electrical system. I have tried it now under many configurations, running everything I can think of running and so far no more problems... and when I do overload the system the outlet breaker always trips. Still I think I will get an electricians second opinion on this one (Thanks Capt. Ron, do you know if he makes trips out to Coronado because that's where I'm located). Again thanks to everyone for the help and advice. -Levin P.S. For Fred: School's going great, just defended the dissertation about a month ago and should be finished with internship in July... all looking good for an August graduation
Check your shore power cord.
Levin: I would suggest that you check your shore power cord. First check from the power source (male end of the cord) then check the female end of the cord. Be sure that you do no see any corrosion or blacking of these ends of the cord. These are exposed to the outdoor elements and can be a source of high resistance.
Levin: I would suggest that you check your shore power cord. First check from the power source (male end of the cord) then check the female end of the cord. Be sure that you do no see any corrosion or blacking of these ends of the cord. These are exposed to the outdoor elements and can be a source of high resistance.
- Status