Yikes!

P

pcator

New member
I am probably the last person to learn this but I will put it out there anyway, just in case. I had a 100 ft extension cord on a reel hooked from the house power to the boat. I was only using about 25 feet of the cord. The rest was wound on the reel. Heat built up inside the reeled cord and melted the insulation and shorted out. I was lucky that it only popped the breaker and did not catch fire.

Now I along with the rest of the world knows not to do this.

Patrick
 
Thank you. I had not considered this possibility before. Good to know!

Any idea of the total amp load on the cord vs. the rated load?
 
Alok":1k7r9fmb said:
Thank you. I had not considered this possibility before. Good to know!

Any idea of the total amp load on the cord vs. the rated load?
Click to expand...

My question too. When my boat's plugged into the house, the only load is the battery charge, the occasional fridge cycling and the low temp heater inside. Not much draw and well within the limits of the cord.
 
Hi,
I have a 30 amp shore power set up in our boat. I don't use anything other than a 30 amp shore power cord. Breakers pop before any meltdowns ocurr. Some extention cords are not rated for even 15 amps. That why building codes call for wire sizes to match amperage ratings on the circut breakers so peeps don't burn down their cribs down yo. Hey why are all these Toyota's passing me? :lol:
D.D.
 
Look at the guage wire of the your extension cords. I use #10 wire in my boat cords--many extension cords are # 14 or #16!

Also look very carefully at the plug where the cord goes into the boat. These often arc when pluged in (both the shore and boat breakers need to be off)--then carbon builds up, and resistance increases. The inlet gets hot, insullation melts--voila--probably the most common cause of boat FIRES!

The coiling of the wire allows the heat to be concentrated. I doubt that there is an effect of the actual coil.
 
There has got to be an electrical engineer out there who will jump on me for this explanation, :shock: but IMHO the over heating in a tightly coiled A.C. line is caused by histeresis, :smilep that is why transformers and coils get hot and will melt down if there is an excessive current draw. :smileo But it's been a long time since I attended classes on A.C. transmission theory :wink

Jack :smiled
 
Perhaps I should amplify what I reported here. It was just your plain everyday extension cord. I was not using a/c or water heater. I have no experiencing of any electrical problems such as sparking at the plugs while connecting to the boat. Or breaker popping.

Just a 100 ft cord on a reel lying between the boat and house. When the circuit breaker (ground fault breaker at the plug) tripped and would not reset I knew I had a problem. I found that a lot of the cord insulation on the reeled portion had melted to the point where I had to cut a lot of the cord from the reel to get it off.

Some times "stuff" happens and I am passing the word on so that someone else won't have this "stuff' happens to them.
 
Ya done good PCATOR...for letting every one know anyway.
Most of the best decisions made by folks in the boating community are made due to having made less than perfect choices in past days. Some day, some way, each of us will melt something, shock ourselves (sometimes more than once.. :mrgreen: ) realise we should not work even around our 2000 watt inverter/charger with a nice glass of iced down Crown Royal while attempting to find out why that satellite radio gizmo down in the back corner of the bench seat with the inverter is not working.... and WHAAAAAAAAAMMMMMIIIIIIEEEEE...

Not that that ever happened to me on Lake Martin in 95 degree weather with moisture on my arms and dripping off the glass running down my arm... :xseek :xseek :smilep :smileo :teeth :thdown :sad :idea :idea

I appreciate your input
 
Byrdman -- is that like working on an F4B Phantom in Chu Lai RVN, confiriming with the radar guys that the radar is powered off and sticking your sweaty arm in the 6+" diameter hole created when you remove the angle of attack probe then falling off the 6' ladder when the 10,000 volt capacitors discharges to your nicely grounded arm? Talk about getting your heart stopped and restarted in a hurry!

I love electricity when it stays inside the wires!

Bill Uffelman
Las Vegas NV
 
AWH Birdman-
It has to be at least as good as waking up after being thrown across room to the wall 6' away. I pulled all the circuit breakers on a computer system with a very highly regulated power supply rated at 1500VDC @ 20amps. I came within 1/4" of an insultated plate lead when I got the shock. :shock: I was out abt 4 minutes.

Some one tried to get more out of the supply by removing the high voltage bleeder resistors - thus the capacitors did not discharge as required. I was reaching for my meter to check the voltage when this occurred. :amgry :shock:

:idea You can NEVER be TOO CAREFUL around electricity. :idea OH, yes, lose the rings!
 
:idea
As to the coiled extension cord- I bet if it had been working fine for an extended period of time it most likely had some broken leads somewhere in the coil form - reducing the cross sectional area, reducing the effective size, for the load that was imposed at the end of its run; thus the heat source at that point.
 
Patrick - suggest you use Google to read about what happens to extension cords as 100 foot conductors. The resistance increases based on the load and gauge of stranded wire, and in some situations that translates into heat buildup that can't be safely dissipated, particularly when the cord is 75% coiled. Your cord should have the gauge marked on it at certain intervals. John
 
Hummm...so, just how many Patricks' do we have as C-Brats now?
It is getting like the Rogers... well...in number anyway. :mrgreen:

Patrick..."Byrdman" Byrd
 
When I was in the U.S Navy, I was part of the electical shop. We pulled shore power cables. These were rated at 450 volt ac. I donot remember the amperage. We had to un roll the whole real. They weighed about 20 - 30lbs a foot. I was told that we had to do it to prevent a magnetic field and heat build up . The same can come from extention cords that are on a real . Depending on the amperage that is beig cosumed. :idea: Depending on the expected load . We had to pull 10- 12 cables. They would come off the real at about 1 mile per hour. Each cable was about 100feet long.
 
I strongly suspect in the OP's case, where he states that the electrical load was minimal, that there were broken strands in the cord, in the coiled up portion, that caused a 'hotspot' heat buildup to the critical point that ignited the insulation...

At higher amperage draws it would be prudent to uncoil the entire extension cord on a reel to improve cooling and reduce the transformer winding effect...

OTOH, if you are drawing enough current to bring the temperature of the jacket on the cord to anything more than barely noticeable above ambient, you are overloading the extension...
 
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