Electrical heads up

andy59

andy59

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I know most of you will be aware of the scenario of having the shore power cable coiled up and when you put a substantial load on it, it will heat up . Just popped down the boat this morning and just with 4500 watt load it started warming up, so just a heads up everyone with the cold weather kicking in ?FEB81803-8007-476A-AE0D-F2A6FCC9F827.jpeg
 
andy59 said:
I know most of you will be aware of the scenario of having the shore power cable coiled up and when you put a substantial load on it, it will heat up . Just popped down the boat this morning and just with 4500 watt load it started warming up, so just a heads up everyone with the cold weather kicking in ?View attachment 128388
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That cable only looks like 1.5mm and will be near its limit even when not coiled up.
 
Coil = magnetic field only .
Resistance , ie narrow dia = heat .

Here is mine .
4BBB940D-3009-4895-9B26-92032909CE3C.jpeg
Note the mooring lines for scale .It’s heavy .

37B6B0EB-C9D0-47DE-BC82-54F64AB4F651.jpeg
Neighbour to the RHS is rag n stick Beny on those twin weedy blue leads .
 
4500 watts, that would draw 18 amps!
What are you running on board, the shore supply breaker is probably only rated at 16A so would trip out.
 
Sneds said:
4500 watts, that would draw 18 amps!
What are you running on board, the shore supply breaker is probably only rated at 16A so would trip out.
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Today , because it was cold and there were things i needed to do i was running, Convector heater 1000w, calorifier 1500w, kettle 2000w, and the battery charger was on (trickle). Totally aware that having a brew (kettle) would be pushing it but kept a hand on cable as an observation hence the post. As a sparks in a previous life am fully aware of regulating load , i often upset the wife by telling her to turn off the hairdryer because i need caffeine :giggle:
 
andy59 said:
It is 2.5mm Chris, just shows how much of an effect the magnetic coil scenario has , 2.5mm with 4500w should be no problem at all ?
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How do you manage to pull 20 ish amps down the cable without tripping the breaker shore side?

I’m assuming it’s a 16A ceeform because 2.5mm artic certainly isn’t rated for 32A ?
 
You can draw 25amps through a 16amp breaker without it tripping for a reasonable time say 10-15 mins
Used to do it a lot ;)
The main load was 2500w well below 16amps it was only at 4500w when the kettle was on thats a couple of minutes.
 
As long as most of the loads are inductive ie heaters a c rated 16 amp breaker will take 20/25 amps for some time. Breakers have time curves higher amps ie dead shorts very fast disconnect. Slightly over can be for long periods. I have seen 20 amps on 16 amp breakers for weeks before we get an issue if the breakers are not subject to the load for too long at any one time. Some cheap breakers are also very slow to respond. Frightening amount of amps to trip them!
 
luke collins said:
As long as most of the loads are inductive ie heaters a c rated 16 amp breaker will take 20/25 amps for some time. Breakers have time curves higher amps ie dead shorts very fast disconnect. Slightly over can be for long periods. I have seen 20 amps on 16 amp breakers for weeks before we get an issue if the breakers are not subject to the load for too long at any one time. Some cheap breakers are also very slow to respond. Frightening amount of amps to trip them!
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I agree, I should have read the rest of the thread first.
 
rafiki_ said:
Your cable is looking rather scruffy. Time for a swap or clean up?
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It’s has been cleaned .Gets scruffy in the yard .
It’s a 32 A .
But they all are on this jetty inc the Benys blue ones which are fitted to splitter into the 32 A plug .

Every year I dismantle both plugs and check the connections .You can smell them as well if they have that electrical burnt whiff = not good .My old SSeeker did but not this stuff .
 
Actual load would have been 18.75 amps and yes its a 16a plug/socket. As Lodden pointed out breakers have a tolerance for drawing more than specified load . Main point of post was being careful having long cables coiled in small spaces. Another little consideration, when was the last time anyone checked shore power leads for corrosion etc, amazing what salt water does to copper/brass (y).
Edit / see Porto is yet again ruthlessly efficient with maintenance regime ?
 
Loddon said:
You can draw 25amps through a 16amp breaker without it tripping for a reasonable time say 10-15 mins
Used to do it a lot ;)
The main load was 2500w well below 16amps it was only at 4500w when the kettle was on thats a couple of minutes.
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Thats handy to know. At this time of year when on board I'm quite often turning off a heater to use the electric kettle.
 
andy59 said:
Actual load would have been 18.75 amps and yes its a 16a plug/socket. As Lodden pointed out breakers have a tolerance for drawing more than specified load . Main point of post was being careful having long cables coiled in small spaces. Another little consideration, when was the last time anyone checked shore power leads for corrosion etc, amazing what salt water does to copper/brass (y).
Edit / see Porto is yet again ruthlessly efficient with maintenance regime ?
Click to expand...
Fessing uptime :)
It started when the Admiral accidentally once dropped an end in the drink .Wasn’t plugged in btw .

Out @ anchor baking hot sunny Med day I opened up said end to dry it in the sun and then noticed apart from obviously damp / wet , saw signs of burnt ends black copper corrosion etc .

Maybe it had had a pull who knows ?

So from then on I annually around the end of season dismantle both ends .Usually @ anchor and check the connections .Emery paper up the metal clamps and make sure the copper wire is a good full section .
No point having 4mm dia and only clamping down say 1/2 of it or what ever.
As inferred ^^^ = potential heat generation
Another tip sniff them the ends while @ anchor not when its plugged in .If it smells burnt …….needs further investigation.
 
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