Wiring 4 cables to a plug

[dcfcsteve]

I need to replace the plug on my electric car charger, and on opening it was surprised to find that there are 4 cables/feeds inside.

There is a standard earth (yellow/green) a live (brown), but then also separate sky blue and dark blue cables.

Does anyone know why they're are 2 blue versions ? Are they both neutrals ? And how should I wire them in the plug ?

Thanks in advance for any help.

 

[plugwash]

What happened to the existing plug? was it moulded or rewirable? was it destroyed beyond recognition?

 

[bernardgreen]

If this plug is on the lead that plugs into the car then most probably one of the blue wires is a signal wire that tells the power source that the lead is plugged into a car and hence it is safe to turn the charger on.

But if you are refering to the mains plug then get a copy of the charger's technical manual to be sure of what goes where in the plug,

 

[ericmark]

Many plugs have contacts to tell something when it is plugged in, and what it is plugged in to, since electric cars can often be charged at different rates, some thing needs to tell the car and charger what rate to charge at, it seems there is more than one method See this wikipedia page you need to find out exactly how yours is wired.

 

[EFLImpudence]

And how should I wire them in the plug ?

Surely if you are replacing the plug the new one must be connected the same as the old one.

 

[ban-all-sheds]

What happened to the existing plug? was it moulded or rewirable? was it destroyed beyond recognition?

Surely if you are replacing the plug the new one must be connected the same as the old one.

Seriously, Steve - why are you having to replace the plug?

 

[dcfcsteve]

Seriously, Steve - why are you having to replace the plug?

The old one has been ruined. Too many times charging the cable with an extension lead attached - which created resistance (and heat) along the length of the long cable.

It's not an ideal thing to do - I know. But when you live in a terraced house, how else are you supposed to recharge an electric vehicle ?

 

[bsr]

Is there an isolation switch near the box? Hopefully a yellow box with a round red switch. If you turn off the electricity to the box and open it, you will find the connections to the flex. You can use a multimeter to test which pin in the plug is connected to which core. If you can't open the box you can cut off the plug and do the same thing.

If the flex has overheated, the replacement needs to use thicker cores and be in one length. I'm not the best person to advise but if you can measure the diameter of the cores and advise someone will be able to recommend the appropriate flex.

 

[dcfcsteve]

Is there an isolation switch near the box? Hopefully a yellow box with a round red switch. If you turn off the electricity to the box and open it, you will find the connections to the flex. You can use a multimeter to test which pin in the plug is connected to which core. If you can't open the box you can cut off the plug and do the same thing.

If the flex has overheated, the replacement needs to use thicker cores and be in one length. I'm not the best person to advise but if you can measure the diameter of the cores and advise someone will be able to recommend the appropriate flex.

Thanks for the response. I'm not sure what box you're referring to though. The car is charged with a cable from the mains power socket into the car. There is no box of any sort involved, even on the cable.

I'm pretty sure the issue re over-heating is because it's attached to a long extension cable. Though as mentioned, I unfortunately don't have much choice on that

 

[bsr]

Ah, so this is plugged into a normal 13 amp socket in the house? Then I would buy a long length of 2.5mm2 4 core Arctic flex. Connect it to the 13A socket in the house and your plug at the other end. That way you don't need an extension lead.

https://quickbit.co.uk/arctic-flex-cable-yellow-per-100m-4-core-2-5mm.html

From a quick check of an online calculator 2.5mm2 is good up to a cable length of at least 50m at 13A.

 

[ban-all-sheds]

The old one has been ruined. Too many times charging the cable with an extension lead attached - which created resistance (and heat) along the length of the long cable.

I was about to say:

That's not a credible mechanism. If the cable is the right size then it won't overheat. Supplying it via an extension lead will not cause it to carry more current.​

But then I thought if the charging circuitry in the car contains a switch-mode power supply then a low voltage caused by voltage drop will indeed make it draw more current.

However it doesn't seem right that it should get that hot - presumably it's the same cable across the whole of Europe, so allowable voltage differences mean it must be made to cope with quite a wide range. Plus it really doesn't seem right that it can get so hot that the connector gets ruined - that's far more likely to be because of a dodgy connection or contact, which could just as well be in the wiring or receptacle on the car. And if it has got that hot it could also easily have damaged the car wiring or receptacle - you should get it checked - could be dangerous.

It's not an ideal thing to do - I know. But when you live in a terraced house, how else are you supposed to recharge an electric vehicle ?

Ask the people who are telling us that we can all just switch to EVs without a care in the world. Where is the car parked when you're charging it? I don't really understand how the house being terraced means you can't have a socket on the front of it....

 

[ban-all-sheds]

Ah, so this is plugged into a normal 13 amp socket in the house? Then I would buy a long length of 2.5mm2 4 core Arctic flex.

Why 4-core? We don't know (yet) why there are 4 cores in the existing cable, but there are only 3 terminals in the plug at the other end....

And how easy will it be to terminate 2.5mm² in a BS 1363 plug?

 

[ban-all-sheds]

I need to replace the plug on my electric car charger, and on opening it was surprised to find that there are 4 cables/feeds inside.

There is a standard earth (yellow/green) a live (brown), but then also separate sky blue and dark blue cables.

Does anyone know why they're are 2 blue versions ?

Sure they aren't blue and black?

Just wondering if it's a 2P+N cable for use where 3-phase is common.

Are they both neutrals ? And how should I wire them in the plug ?

Two questions, but the second one is the most important, and one which I expect is puzzling everyone here.

1. Which pins are the conductors connected to in the 13A plug?
2. Having got your replacement connector, why on earth would you not wire it the way that the old one was wired rather than wondering which way to wire it?

 

[SimonH2]

But then I thought if the charging circuitry in the car contains a switch-mode power supply then a low voltage caused by voltage drop will indeed make it draw more current.

It is almost certainly going to be a switch mode converter. However, it should be programmed to limit the current in the charging cable rather than the power - if it's limiting the charging power to what a 13A socket can provide, then it should be restricting the current to 13A and the power will be whatever it works out at for the voltage available.

Ask the people who are telling us that we can all just switch to EVs without a care in the world.

Where is the car parked when you're charging it? I don't really understand how the house being terraced means you can't have a socket on the front of it....

A socket yes, but unless you have off-road parking you'll end up with a cable across the pavement and (if it's anything like where we used to live) half way across town to reach the car. AIUI the authorities aren't keen on cables across the pavement.
And you come across people who complain if you park in "their" bit of the road - it must be theirs because it's in front of their house. Just imagine what some of them would be like if they expected to park in front of their onw house so they could plu the car in

 

[333rocky333]

I was about to say:

That's not a credible mechanism. If the cable is the right size then it won't overheat. Supplying it via an extension lead will not cause it to carry more current.​

But then I thought if the charging circuitry in the car contains a switch-mode power supply then a low voltage caused by voltage drop will indeed make it draw more current.

However it doesn't seem right that it should get that hot - presumably it's the same cable across the whole of Europe, so allowable voltage differences mean it must be made to cope with quite a wide range. Plus it really doesn't seem right that it can get so hot that the connector gets ruined - that's far more likely to be because of a dodgy connection or contact, which could just as well be in the wiring or receptacle on the car. And if it has got that hot it could also easily have damaged the car wiring or receptacle - you should get it checked - could be dangerous.



Ask the people who are telling us that we can all just switch to EVs without a care in the world. Where is the car parked when you're charging it? I don't really understand how the house being terraced means you can't have a socket on the front of it....

I read that you should not use standard 13 amp sockets and you can buy a 13 amp socket now that has EV marked on the back and its suitable for the prolonged time needed to charge some cars
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