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Blade
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Discussion Starter #1
I was shocked today to find 5 cores in the cable between the ’brick’ on my slow charging cable and the 3 pin plug! I was changing the plug as the original moulded plug was too large to fit under the waterproof flap of my Rolec Wallpod. Can anyone offer any advice on wiring up my new slimmer 3 pin plug with the 5 cores discovered in the cable? There is a standard Earth, Live and Neutral core with two additional grey covered cores - both with a smaller cross section.

Thanks in unity

Jak
 

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I believe there's a thermal sensor in the 3-pin plug to ensure that your plug/socket doesn't overheat due to any loose terminals or or unknown unpredictables.
Deborah.
 

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There have been a few threads on this topic over the years. As @High & Dry says the original plug has a thermister wired to the two extra leads that reduces power if the plug overheats. This is one typical thread.

 

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Blade
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Discussion Starter #4
Do you know if there is any way of successfully wiring it into a standard 3 pin plug?
 

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Yes. But outside my pay grade. Seems to involve inserting a resister, replacing the original equipment, or making amendments inside the EVSE itself. As I said, many threads over the years. The forum search function is your friend.
 

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you might be able to pare away the plastic on the original plug and extract the thermistor. Alternatively, someone might have posted the value somewhere. The linked thread mentions a 22k NTC thermistor, but i dont know if thats the same charger as you have.

If you have a meter, you can very likely take some readings from your existing sensor at a few different temperatures to figure out what it is.
 

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It should of course be pointed out that replacing the thermistor with a suitable fixed value resistor is just a way to "fool" the EVSE into thinking the plug is not overheating when it might actually be. In other words this safety feature is being defeated by doing so. If this plug later catches fire or melts then you might well regret this.

To be honest cutting the plug off was a mistake and you're in a bit of a mess now.

It's not easy to repair this in a properly satisfatory way, certainly not with a regular screw terminal plug as even if you used an appropriate thermistor to maintain temperature sensing there isn't an easy way in such a hollow plug to provide thermal bonding between a thermistor and the parts that get hot (mainly the fuse holder and phase pin) while at the same time maintaining adequate insulation between the high voltage and the sensor.

In a moulded plug like the original there are no hollow voids apart from the fuse holder space, with any other spare space filled in with plastic which acts as both electrical insulation and a (partial) thermal conductor between the heat source and the thermistor allowing it to sense when the plug is heating up.

If you use a screw terminal plug you're going to have to bodge it with a resistor and lose temperature sensing, and its probably infeasible to rejoin the cable depending on where you cut it. (Unless you cut it close to the EVSE end and have enough length to reterminate it inside, but I'm guessing you probably cut it close to the plug)

The only 100% professional repair would be to try to get hold of a faulty EVSE of the same model and steal the cable from it, reterminating it inside, getting you back to where you started.

And then change your socket to one with a bigger cover so that the original plug size fits...
 

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Blade
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Discussion Starter #8
Thanks all

DBM - you mentioned that there is a socket with a bigger cover - is this one made by Rolec? If you have any details id appreciate thatbotherwisw I assume I’ll,find it in a search. I just don’t remember it being an option.

Jak
 

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jim5452
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>>Do you know if there is any way of successfully wiring it into a standard 3 pin plug?<<<<
There is a post on here somewhere where someone had one of these rewired( I believe it was connected to HANDYANDY it either belonged to him or he mended it)
I hope I am right and this was not another webdite
 

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Thanks all

DBM - you mentioned that there is a socket with a bigger cover - is this one made by Rolec? If you have any details id appreciate thatbotherwisw I assume I’ll,find it in a search. I just don’t remember it being an option.

Jak
I use one of these

 

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30KW Tekna (2017)
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I saw one for sale on eBay not so long ago, the seller said the 3 pin plug had been removed and re-wired with a commando plug.

If your going to fudge a resistor, it may be a safer option than an 3 pin domestic?
 

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Thanks all

DBM - you mentioned that there is a socket with a bigger cover - is this one made by Rolec? If you have any details id appreciate thatbotherwisw I assume I’ll,find it in a search. I just don’t remember it being an option.

Jak
So did you save the old plug, and how much wire did you leave?
 

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So did you save the old plug, and how much wire did you leave?
 

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I’ve used these and the T version in garden lighting - they will achieve a safe joint if you have spare cable length left (although I bet you snipped next to the plug).
 

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Thanks all

DBM - you mentioned that there is a socket with a bigger cover - is this one made by Rolec? If you have any details id appreciate thatbotherwisw I assume I’ll,find it in a search. I just don’t remember it being an option.

Jak
I have repaired one for a friend for his ENV 200.
But most certainly proceed with utmost caution.
My mate is fully aware and only uses it on site when he is always round and about it, I would never recommend the likes of plugging it in and leaving it overnight.

The key to get this to work is a 22k Ohm resistor soldered on to the smaller cores.
Use a very heavy duty MK Duraplug plugtop.

If you have the slightest doubt over your competency then use a professional service.
 

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Blade
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Discussion Starter #19
Thanks - I do doubt my ability - is this a job for any electrician or am I looking for a specialist? Thanks
 

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Thanks - I do doubt my ability - is this a job for any electrician or am I looking for a specialist? Thanks
Any half decent spark with a soldering iron, the resistor and some heat shrink would be able to do it.
Let's face it, I managed. 😂
 
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