Are shore power inlets dangerous?

[BC Dave]

good ideas;

"slather the male plug recepticle with di-electric grease to keep the water out"

some sort of water deflector or cover is also a good idea; I'm considering a self closing exterior plastic cover after considering the problems ...

but this will not replace loose connections as mentioned ...

Cheers Dave

[Shadow Catcher]

I had another thought. I had one of the clear end 12 ga extension cords from Harbor Freight that when I first plugged it in sparked. Looking through the female end afterword I could see no cause but did see some discoloration. I have continued to use the cord.

There is some indication that some Chinese made cords are not the stated gauge, or the copper adulterated and cover it up using heavy insulation. One test is to measure resistance. 12 gauge should have about 1.6ohms/1000 feet, or .32 ohms if you tie both prongs together at the male end and measure the resistance between slots at the female end of a 100 feet cable. 14 ga, 0.5 ohms. A 16 ga. would have 0.8 ohms. To get an accurate reading first touch DMM probes together to get a read out on inherent meter and lead resistance then subract.

[Larwyn]

I had another thought. I had one of the clear end 12 ga extension cords from Harbor Freight that when I first plugged it in sparked. Looking through the female end afterword I could see no cause but did see some discoloration. I have continued to use the cord.

There is some indication that some Chinese made cords are not the stated gauge, or the copper adulterated and cover it up using heavy insulation. One test is to measure resistance. 12 gauge should have about 1.6ohms/1000 feet, or .32 ohms if you tie both prongs together at the male end and measure the resistance between slots at the female end of a 100 feet cable. 14 ga, 0.5 ohms. A 16 ga. would have 0.8 ohms. To get an accurate reading first touch DMM probes together to get a read out on inherent meter and lead resistance then subract.

A good theory but kind of hard to apply in our case.

For my 25 foot 12 gauge extension cord I would be looking for a reading of .016 ohms (for 50 feet of conductor). I'm afraid that the lowly Fluke 87 which I have is not likely to have the resolution necessary to accurately measure and display a reading that low. The specified resolution of the meter on the ohms range is .1 ohm (very optimistic) and the accuracy is .05% + 1 digit (least significant digit). Even if I had a Ductor (milliohm meter) laying around, the actual logistics of using the dual prong test probes it requires would make this test quite difficult.

Maybe pushing a known or measured current through the cord and measuring the voltage drop would give a better indication but then you have the accumulated error of the two measurements (voltage and current) to deal with. In my experience reading such low resistance takes some rather expensive and specialized measuring equipment.

[caseydog]

Well, I went out to take a pic of my cord, and it turns out that on mine, it was the MALE end that got a bit toasted, not the female end. Getting old sucks.

So, in my case, it was probably a problem with the park's power outlet, or rainwater getting to the park's power outlet.

Here is what mine looks like. This is a 12GA Rigid (Home Depot) 15 Amp cord....



CD

[CASHCOW]

Well, I went out to take a pic of my cord, and it turns out that on mine, it was the MALE end that got a bit toasted, not the female end. Getting old sucks.

So, in my case, it was probably a problem with the park's power outlet, or rainwater getting to the park's power outlet.

Here is what mine looks like. This is a 12GA Rigid (Home Depot) 15 Amp cord....



CD

CD it looks like to me you just let the smoke out of your cord

[dovaka]

this is slightly related but i remember a few years ago i had a gmc jimmy and all of the sudden in the winter when i got home my running lights would very softly blink eradically for a unspecfied period of time and i couldnt figure out what it was for the life of me. i had 2 insane gel batteries in the truck so it never went dead over night and i would just let it blink all night until one day i realized my 7 way trailer outlet was full of salt and it was causing it to arc inside there
once i cleaned that out and packed it full of dielectric grease everything was fine

[Lawnjockey]

Those pictures are not real "shore power" fittings as designed for real boats. A real shore power fitting has a screw on cover and the female end of the cord has a nut that fits the treads on the outlet. When tightened it seals the connection. The newer fittings are plastic but you can still find the old cromed bronze ones if you look hard, they are pricey. The cord and female fitting are coated with a rubber like material and the nut on the cord is plastic.


Jocko

[halfdome, Danny]

The latest packaging for the outlets in question. It says it's for trailers too. Danny

[legojenn]

I think that the British have us beat with respect to plugs. Only the tips are metal and the plugs are fused. I don't know how that could arc.

[dovaka]

I think that the British have us beat with respect to plugs. Only the tips are metal and the plugs are fused. I don't know how that could arc.

you dump a bunch of cruddy water on that for a few hours and it could still arc out

[jackdaw]

I think that the British have us beat with respect to plugs. Only the tips are metal and the plugs are fused. I don't know how that could arc.

That's a domestic 13 amp socket and plug that we use for all our mains appliances over here

However when we go camping over here, we use a 16 amp plug and socket to hook up to the campsite post. They have no fuse

But all our campsite supplies have to have individual trip switches, and then we have a distribution board of some sort on our end, in the trailer/ caravan with another trip on each cuircuit as well as the main trip.

So thats three trip switches and a fuse ...... plenty of protection I think.

The conection to the caravan is often through a flush fitting box with a
flap. The plug and socket are prity well protected from the weather. The lid can very nearly close with the lead pluged in.

[BC Dave]

The conection to the caravan is often through a flush fitting box with a
flap. The plug and socket are prity well protected from the weather. The lid can very nearly close with the lead pluged in.

That looks like someone was thinking when they designed it!

Perfect; covered and water sheding!