Shore power plug keeps burning out...
- Thread starter Levin
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Somthing else to Check
I did not see it anywhere else that someone had mentioned. Make sure you are getting 120 volts at your dock. There may be lots of boats on a single leg or your way out on the end of a sigle run all sorts of things.
I did not see it anywhere else that someone had mentioned. Make sure you are getting 120 volts at your dock. There may be lots of boats on a single leg or your way out on the end of a sigle run all sorts of things.
Thanks...
Hello again everyone...
First off... thanks a ton for all the advice. It's a lot to take in all at once but sounds like some good suggestions. I have replaced the plug on the boat once before when this got bad and assumed that would be the end of it. Obviously I'm missing something because this has happened all over again. I think I might be drawing too much current because I do use a space heater in the winter (yes San Diego can get cold in the winter) and I use a coffee maker, and then there is the hot water heater, the battery charger, and so on. Also I live at fairly inexpensive and not to well maintained marina (Fiddler's Cove) which I remain at because it cost me about 1/3 what it would to live anywhere else. Their power boxes look to be about 20 years old at least so I have no doubt they aren't putting out what they are rated... I'm sure that plays a part in this too after reading all the posts.
Anyway I guess what I have to do is replace the plug and perhaps coat the new one in this Dielectric stuff (or however you spell that). I think right now I'm using a Manco (or again however you spell that) plug so I don't think there is a higher quality one. I guess I just don't want to replace this plug for a third time only to watch yet another one burn out. Short of moving to another marina is there anything else I can do to keep the new plug from burning up as well? I can't go up to 50amp service because it's not offered where I live, and I guess I can install a second 30amp plug on the boat and run part of my stuff off that, but as I only have one 30amp plug coming off the dock available I don't know if adding a second one to my boat would do me any good.
Thanks again for the suggestions and if you have any other ideas about how I can avoid burning up yet another plug in a year's time I would greatly appreciate it.
Take care,
-Levin
Hello again everyone...
First off... thanks a ton for all the advice. It's a lot to take in all at once but sounds like some good suggestions. I have replaced the plug on the boat once before when this got bad and assumed that would be the end of it. Obviously I'm missing something because this has happened all over again. I think I might be drawing too much current because I do use a space heater in the winter (yes San Diego can get cold in the winter) and I use a coffee maker, and then there is the hot water heater, the battery charger, and so on. Also I live at fairly inexpensive and not to well maintained marina (Fiddler's Cove) which I remain at because it cost me about 1/3 what it would to live anywhere else. Their power boxes look to be about 20 years old at least so I have no doubt they aren't putting out what they are rated... I'm sure that plays a part in this too after reading all the posts.
Anyway I guess what I have to do is replace the plug and perhaps coat the new one in this Dielectric stuff (or however you spell that). I think right now I'm using a Manco (or again however you spell that) plug so I don't think there is a higher quality one. I guess I just don't want to replace this plug for a third time only to watch yet another one burn out. Short of moving to another marina is there anything else I can do to keep the new plug from burning up as well? I can't go up to 50amp service because it's not offered where I live, and I guess I can install a second 30amp plug on the boat and run part of my stuff off that, but as I only have one 30amp plug coming off the dock available I don't know if adding a second one to my boat would do me any good.
Thanks again for the suggestions and if you have any other ideas about how I can avoid burning up yet another plug in a year's time I would greatly appreciate it.
Take care,
-Levin
Second 30 Amp Socket
You could use a "Y" out of your pedestal to a second 30 amp socket and that would shift the burden to the pedestal rather than you boat. You may burn up the dock but that is better than burning the boat. Another perhaps better option is to use the "Y" on a neighbors pedestal who only runs a battery charger or other small loads most of the time. Of course there is always the option of not using the space heater and getting a dog or a girl to keep you warm. A dog is less trouble and will not add any additional load on you power system.
You could use a "Y" out of your pedestal to a second 30 amp socket and that would shift the burden to the pedestal rather than you boat. You may burn up the dock but that is better than burning the boat. Another perhaps better option is to use the "Y" on a neighbors pedestal who only runs a battery charger or other small loads most of the time. Of course there is always the option of not using the space heater and getting a dog or a girl to keep you warm. A dog is less trouble and will not add any additional load on you power system.
Re: Thanks...
When I wired my boat I installed a 30 amp main breaker and several 15 amp branch breakers on the assumption that I could run 4 circuits at 10 amps and not overload any of the branch circuits but that I could overload the supply.
My house has a 200 amp main breaker and a variety of branch circuits that range from 15 amp lighting circuits to a 40 circuit for the AC. If I add the capacity of all of the branch circuits I am about 200 percent more than the main breaker in the supply. I have never trip the main and rarely trip a branch but the potential is there.
When I wired my boat I installed a 30 amp main breaker and several 15 amp branch breakers on the assumption that I could run 4 circuits at 10 amps and not overload any of the branch circuits but that I could overload the supply.
My house has a 200 amp main breaker and a variety of branch circuits that range from 15 amp lighting circuits to a 40 circuit for the AC. If I add the capacity of all of the branch circuits I am about 200 percent more than the main breaker in the supply. I have never trip the main and rarely trip a branch but the potential is there.
Rain?
I found that the big yellow plugs I presume you have are difficult to prevent rain ingress into the connections and rain water does cause this arcing and localised heating.
To overcome this I have sprayed the plug and socket with WD40 and greased the threads with Vaseline. Make sure the backing ring is done up realy tight. Twist the plug as you turn the outer ring to make sure it is really tight.
Unlikely to be an overload problem as the breaker would drop out before it overheats this much.
I found that the big yellow plugs I presume you have are difficult to prevent rain ingress into the connections and rain water does cause this arcing and localised heating.
To overcome this I have sprayed the plug and socket with WD40 and greased the threads with Vaseline. Make sure the backing ring is done up realy tight. Twist the plug as you turn the outer ring to make sure it is really tight.
Unlikely to be an overload problem as the breaker would drop out before it overheats this much.
dang thumbs
Keep hitting the wrong button.
If you replace it with quality equipment and it goes bad in exactly the same way it is the "other part" that is causing the problem. I go talk to the marina and see if they will let you turn off your section of dock power so you can inspect the outlet and replace repair it. I suspect there is corrosion on it and that is causing the resistance and burns.
Is the dock side burned?
Keep hitting the wrong button.
If you replace it with quality equipment and it goes bad in exactly the same way it is the "other part" that is causing the problem. I go talk to the marina and see if they will let you turn off your section of dock power so you can inspect the outlet and replace repair it. I suspect there is corrosion on it and that is causing the resistance and burns.
Is the dock side burned?
Re: Thanks...
Levin, a couple of additional thoughts. Since you live aboard your power consumption and associated wear and tear shows up a lot quicker than someone who only uses the boat on weekends. I still think having your issue repeat annually seems excessive. You've received a lot of good advice on why your cord is burning up prematurely. Bottom line, the issue lies with the fact the connection at the boat appears to be your weakest link. In addition to a new cord and socket I'd do what I could to take any strain off the shore cord. Constant movement of the boat could allow the cord to move around, even if very slightly, in the socket. Continuous movement could create a poor connection and add to your problem. Remember these are not the tighest fit when you compare them to a typical electrical connection. To help stabilize things I always tie a bungy cord between the stern rail to about 3' from the end of the cord, leaving a loop between the cord and socket. The bungy cord takes the strain off the shore cord and does a good job of keeping the connection stable. If you're not already doing so I'd try it. It certainly can't hurt.
Good luck
Mike
Levin, a couple of additional thoughts. Since you live aboard your power consumption and associated wear and tear shows up a lot quicker than someone who only uses the boat on weekends. I still think having your issue repeat annually seems excessive. You've received a lot of good advice on why your cord is burning up prematurely. Bottom line, the issue lies with the fact the connection at the boat appears to be your weakest link. In addition to a new cord and socket I'd do what I could to take any strain off the shore cord. Constant movement of the boat could allow the cord to move around, even if very slightly, in the socket. Continuous movement could create a poor connection and add to your problem. Remember these are not the tighest fit when you compare them to a typical electrical connection. To help stabilize things I always tie a bungy cord between the stern rail to about 3' from the end of the cord, leaving a loop between the cord and socket. The bungy cord takes the strain off the shore cord and does a good job of keeping the connection stable. If you're not already doing so I'd try it. It certainly can't hurt.
Good luck
Mike
I made the suggestion but I guess it got lost. REDUCE your CONSUPTION. The biggest and easy way to do it this is to turn off the water heater. With the water heater and the space heater, you are using up all your amps. Kick on the battery charger and you overload the system. But in actual terms, it's the other way around. The battery charger works more often then the water heater but is the biggest draw on the boat. That's why I said to turn if off when you need the other things like the heater. Turn on the water heater two times a day for 30 minutes and you are good.
Hello again everyone...
So now it sounds like there could be two causes:
1) That somehow I'm pulling too much power and this is burning out the plug
2) That somehow rain, water, or moisture is getting in between the shore power cord and the connection on the back of my boat and leading to problems.
I believe that #2 is the most likely answer because I don't think that I draw too much power. As someone pointed out I have a lot of breakers that could trip if I did pull too much power (and they don't). There is the 30amp breaker on the dockside shore power box, the main 30amp breaker on my boat, and the 15amp breaker on my "outlets" switch... and none of these trip on a regular basis (although if I forget to turn off the space heater when I start the coffeemaker I will trip the 15amp outlets switch, but that doesn't happen too often). Anyway this is leading me more and more to believe that the problem is somehow moisture... but that doesn't make a lot of sense because I live in San Diego where it is fairly dry all year round (rains a bit from January to March, but not that much) and I always make sure the plug is well screwed into place.
Should I be doing more? Should I put Vaseline or WD-40 around the plug as was suggested? Would that Dielectric stuff another member mentioned help with a moisture problem if that's the case? Or is this just a flaw with this type of boat as one fellow Hunter owner pointed out and I should just budget in a new plug and cord every year and a half or so (about $250 total... a real shame)...
I have to thank everyone for their suggestions. This is a real problem and like I said before I don't want to keep just replacing this plug without figuring out the reason that this happens because I will only have to keep doing it time and time again if that is the case.
I appreciate everyone's thoughts
Take care,
-Levin
So now it sounds like there could be two causes:
1) That somehow I'm pulling too much power and this is burning out the plug
2) That somehow rain, water, or moisture is getting in between the shore power cord and the connection on the back of my boat and leading to problems.
I believe that #2 is the most likely answer because I don't think that I draw too much power. As someone pointed out I have a lot of breakers that could trip if I did pull too much power (and they don't). There is the 30amp breaker on the dockside shore power box, the main 30amp breaker on my boat, and the 15amp breaker on my "outlets" switch... and none of these trip on a regular basis (although if I forget to turn off the space heater when I start the coffeemaker I will trip the 15amp outlets switch, but that doesn't happen too often). Anyway this is leading me more and more to believe that the problem is somehow moisture... but that doesn't make a lot of sense because I live in San Diego where it is fairly dry all year round (rains a bit from January to March, but not that much) and I always make sure the plug is well screwed into place.
Should I be doing more? Should I put Vaseline or WD-40 around the plug as was suggested? Would that Dielectric stuff another member mentioned help with a moisture problem if that's the case? Or is this just a flaw with this type of boat as one fellow Hunter owner pointed out and I should just budget in a new plug and cord every year and a half or so (about $250 total... a real shame)...
I have to thank everyone for their suggestions. This is a real problem and like I said before I don't want to keep just replacing this plug without figuring out the reason that this happens because I will only have to keep doing it time and time again if that is the case.
I appreciate everyone's thoughts
Take care,
-Levin
It sounds like a loose, and or corroded connector to me. The connectors need to be replaced and the conductors need to be wire brushed and reconnected with an electrical inhibitor paste added to improve conductivity and prevent corrosion. This is a rare but common occurrence in meter sockets and load centers of houses and buildings which draw high loads. In most cases in residential dwellings, the service entry cable conductors are Aluminum which is notorious for this problem. Have an electrician pop the cover off the receptical or load center, and you will be able to see this problem as plain as day. The fact that your boat is drawing a high load really componds this problem even more. That box must be really warm to the touch when you have everything turned on in the boat.
Joe
Joe
Last yer at our marina there were 8 "burn out" of the wires behind the shore conector. Some were hot enough to melt the metal prongs. Not one of these cases di any circuit breakers blow.
Different boat manufacturers. Both marinco and hubbell. I think abyc should rethink there specs or someone is doing something wrong. Regardless of not cleaning the contacts or overloading the line, owneres will do this without knowing it. Like in your home you would assume the breaker will shut off. This is rarly the case.
Most modern boats have the shore conections in the rear locker. many stuff junk there, great for starting a fire the next time the pooorly designed electrical system fail.
What I described is the real world circumstance, not theory.
Different boat manufacturers. Both marinco and hubbell. I think abyc should rethink there specs or someone is doing something wrong. Regardless of not cleaning the contacts or overloading the line, owneres will do this without knowing it. Like in your home you would assume the breaker will shut off. This is rarly the case.
Most modern boats have the shore conections in the rear locker. many stuff junk there, great for starting a fire the next time the pooorly designed electrical system fail.
What I described is the real world circumstance, not theory.
Well from a over 30 year plant matiance point of view
Twist lock plugs SUCK big time
and allways burn up if they are used in wet conditions there is know way to clean the female parts OR see when they are in marginal condition
If you running high amps connections need to be checked WHICH is why they use thermal guns on pannles to find HOT spots
Pin and Sleeve plugs have been used in wet areas because of the better contact area on LAND for so long i cant remenber when we started
Look at any fast food place and see whats hanging on the fry machine
I can tell you right NOW that most any normal plug can not carry its fully rated current in anything less than lab perfect conditions BUT a pin and sleeve will
Twist lock plugs SUCK big time
and allways burn up if they are used in wet conditions there is know way to clean the female parts OR see when they are in marginal conditionIf you running high amps connections need to be checked WHICH is why they use thermal guns on pannles to find HOT spots
Pin and Sleeve plugs have been used in wet areas because of the better contact area on LAND for so long i cant remenber when we started
Look at any fast food place and see whats hanging on the fry machine
I can tell you right NOW that most any normal plug can not carry its fully rated current in anything less than lab perfect conditions BUT a pin and sleeve will
Corrosion
I never burned out my shore power cord but I did have a serious rain leak around the shore power thru hull on my 2000 340. I had to re-bed the thru hull to keep my aft lazerette and aft bunk dry. I have not had a problem to date with the wires but I do check the shore power connector when the AC is running, to see if it is heating up.
I never burned out my shore power cord but I did have a serious rain leak around the shore power thru hull on my 2000 340. I had to re-bed the thru hull to keep my aft lazerette and aft bunk dry. I have not had a problem to date with the wires but I do check the shore power connector when the AC is running, to see if it is heating up.
I use WD40
I spray all electrical connections with WD40 every time I remove or attach. I used to fry power cords every year. Has not happened since I started doing this. I have a 2004 Hunter 41 with 2-30 amp circuits. I also spray the RAM mic attachment every time I attach it and when I remove it to stow it. This may not solve your problem but I believe this is a good preventive maintenance practice.
I spray all electrical connections with WD40 every time I remove or attach. I used to fry power cords every year. Has not happened since I started doing this. I have a 2004 Hunter 41 with 2-30 amp circuits. I also spray the RAM mic attachment every time I attach it and when I remove it to stow it. This may not solve your problem but I believe this is a good preventive maintenance practice.
There is only one possible problem: Resistance at the connections. Loose and/or corroded metal to metal creates resistances which causes a voltage drop and the dissipation of power in the form of heat. It's a mini-toaster. I have noticed that these shore power (30 amp) connectors don't really have a lot of force applied to the prongs from the receptacle. There may be a higher quality end fitting for the cord or you may have to disassemble the socket and manually sqeeze the pieces together so they apply more physical pressure. This burning effect is pronounced if you use motor loads like AC or fans. To monitor your progress, feel the connector when it's loaded - if it's hot, there's resistance and a connection that's too loose for the load.
In an 'overload' situation, a circuit breaker should trip before any wiring or connectors get hot enough to melt.
Final words: Clean and tight. Low resistance. No heat at connector.
David Hoch
S/V Abundance
Hunter 260
In an 'overload' situation, a circuit breaker should trip before any wiring or connectors get hot enough to melt.
Final words: Clean and tight. Low resistance. No heat at connector.
David Hoch
S/V Abundance
Hunter 260
Another correction, since it's come up several times.
Increases in current due to reduced voltage only happens with induction motors, since the connected (driven) load is essentially constant-torque and speed (and therefore, constant power). I = P / V applies, if you ignore efficiency and power factor (or just assume they're constant). Air conditioning and refrigeration compressor motors will, therefore, draw more current as the voltage is decreased.
Purely resistive loads, like water heaters, hair dryers, and space heaters, will draw less current as the voltage decreases, since the impedance is essentially fixed. For those, I = V / R does apply (R is essentially a constant, so as V goes down, I goes down). A 1500W heater is only 1500W at the rated voltage (usually 120V in North America), and will draw less current and produce less heat at lower voltages.
Increases in current due to reduced voltage only happens with induction motors, since the connected (driven) load is essentially constant-torque and speed (and therefore, constant power). I = P / V applies, if you ignore efficiency and power factor (or just assume they're constant). Air conditioning and refrigeration compressor motors will, therefore, draw more current as the voltage is decreased.
Purely resistive loads, like water heaters, hair dryers, and space heaters, will draw less current as the voltage decreases, since the impedance is essentially fixed. For those, I = V / R does apply (R is essentially a constant, so as V goes down, I goes down). A 1500W heater is only 1500W at the rated voltage (usually 120V in North America), and will draw less current and produce less heat at lower voltages.
Power Plugs burning out.
Although there is a lot of good info posted here I have a very simple rule. If a plug burns out you replace both the plug and socket at the same time. This is because the socket must have some or a lot of dammage if the plug burns out. When you replace the plug the socket has increased resistance from the burn out. This increased resistance causes heat that causes the plug to have a shortened life.
Good luck
Ray
Although there is a lot of good info posted here I have a very simple rule. If a plug burns out you replace both the plug and socket at the same time. This is because the socket must have some or a lot of dammage if the plug burns out. When you replace the plug the socket has increased resistance from the burn out. This increased resistance causes heat that causes the plug to have a shortened life.
Good luck
Ray
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