Discuss new circuit in combustible CU and SPD question in the UK Electrical Forum area at ElectriciansForums.net

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Hi fellow sparks,

I've just started out on my own so I'm spending a lot of my time trying to find out the correct way of doing things of installations I havent done before by going through the regs and such. I've been sent this pic by a potential client showing their CU in the garage.
The job is to install an EV charger which they have bought from amazon 🥺 the charger is from a brand called luswaysol. Tried looking through the items description and specs and even tried to google it, couldnt find anything about PEN fault detection device.

The questions I have are

1. The CU has a spare way however the the CU is of combustible material which is not upto regs, as I am thinking of installing a new circuit, does the CU need to be changed to a non combustible/metal CU in order for me to install a new circuit? I cant find the requirements of a new circuit on a existing installation. All I found is on 511.1 every item of equipment shall comply with the relevant requirements of the applicable british or harmonized standard, appropriate to the intended use of the equipment. Also 527.1.1 The risk of fire shall be minimized by the selection of appropriate materials and erection in accordance with section 527. The only thing is, it seems a bit over the top to install a new CU just to just change from plastic to metal so I cant imagine it would be absolutely necessary.

2. There is no SPD on this CU as you can see from the pic, I have not asked them for a picture yet of the CU in the house which most likely feeds this garage CU. My question here is and i think i know the answer... if the CU which feeds the garage CU has an SPD installed then this garage CU doesnt need an SPD? as it has one installed further up the install... i see people installing spd on each separate CU but im presuming thats of course because its been split via henleys and there is no SPD before each CU therefor each CU needs a SPD...

here is a link for that weird EV charger the client has sent me:

sorry if these are silly questions but If anyone could point me in the right direction please and if you know the regs for the requirements or roughly what section they are in so i could have a read up please I would really appreciate it.

in terms of the job, im not sure i want to do it as they have bought some random EV charger and the info/specs dont seem to appealing for me to install

thank you

972673a3-93c2-43b0-bfdd-65fee0289023.JPG
 
I’d be tempted to add a specific board just for the EV that is non-combustible, has SPD and the proper type AC RCD ( can’t tell what the rcd mainswitch is there)

The spec calls for 32A…. Is the supply cable to this board adaquate?



Make it perfectly clear that anything wrong with the charge point itself is his responsibility.
 
I’d be tempted to add a specific board just for the EV that is non-combustible, has SPD and the proper type AC RCD ( can’t tell what the rcd mainswitch is there)

The spec calls for 32A…. Is the supply cable to this board adaquate?



Make it perfectly clear that anything wrong with the charge point itself is his responsibility.
hi, I was thinking that too, i'd feel more comfortable changing to a metal spd board, but if i wanted to use the incoming supply cable it would probably be better to change that board rather than split into a henley and go back into this and the new board? as that way upstream the breaker will only be feeding one board as opposed to 2 or would that still be alright since the breaker will be protecting the cable from overcurrent anyways? feels a bit messy splitting it into 2 if im being honest. especially as its an armoured, i'd have to go into an enclosure first then ino henleys and into both boards...

also did you mean type A RCD?

and yes i would tell them that the charger is their responsibility since they have bought it. anything im not supplying i wont offer warranty if im being honest as i havent got my mark up which covers me to fix it. but the issue i have is, if it hasnt got open PEN fault device i dont even want to install it as i wont be able to connect a TNS or TNCS earthing supply to it and will have to put an earth rod in and im not doing that for an ev and i dont think they will pay for it if they went on amazon for an ev
 
I probably wouldn't be touching this with a very long pole. Google searches show next to nothing for that brand which is unusual. I would only consider this job if they permit you to go with a known brand of EV charger.
Yeah exactly what i was thinking... ev installs have a lot of requirements to meet regs and that charger looks real sketchy so i'll advise them to get a proper charger or let me get one or i'll just bin the client

but in terms of my questions for learning purposes so i know in the future... if there is a combustible board, and i need to install a circuit, could i add a circuit into that board? is there any regulations that mention otherwise or anything about this or something similar to this to refer to?

if there is an SPD upstream of a CU that you want to install a circuit on, you would not need to install an SPD on that CU right as the SPD upstream is protecting it all?

also, are CT clamps an absolute requirement for EV's? i know there is a mention of load curtailment on reg 722.311.201 but is this only after an assessment say where the house has other equipment that draws a lot current such as electric cookers and showers etc? lets say if there is a house where it only has low load circuits such lighting, and rings, is it necessary?

thank you
 
I think you would find the code of practice for EV a worthwhile read (if you haven't already). For one thing, it points to the regulation that says each EV charge point should be protected INDIVIDUALLY by an RCD, thus ruling out the existing consumer unit setup, as the RCD main switch also protects several other circuits.

I would not recommend installing an EV charger that doesn't have pen fault protection.

For some of the other questions, I find the list of questions and answers on the Electrical Safety First website very helpful.


One of the questions relates specifically to adding a new circuit to an insulated consumer unit.
 
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I think you would find the code of practice for EV a worthwhile read (if you haven't already). For one thing, it points to the regulation that says each EV charge point should be protected INDIVIDUALLY by an RCD, thus ruling out the existing consumer unit setup, as the RCD main switch also protects several other circuits.

I would not recommend installing an EV charger that doesn't have pen fault protection.

For some of the other questions, I find the list of questions and answers on the Electrical Safety First website very helpful.


One of the questions relates specifically to adding a new circuit to an insulated consumer unit.
Hi,

I have the code of practice and I will slowly be going through it.

I wouldn’t want to install an ev without PEN fault to be honest.

Thank you very much for the link to electrical safety first I just went through it and found a lot of helpful answers with references to the regulations and found my answer I think it was on q100 or 101
 
just tell the client you work to a standard...and that ev charger doesnt meet your standards and advise them on another make and model that you would be happy to fit
so I’ve advised them and they’ve asked me which charger would I recommend. They’ve also sent me a picture of the main consumer unit which feeds the garage board. No SPD. Attached below.

Looks like the garage supply is on a 32MCB, not sure what size the cable is. If I’m lucky enough it’s a 10mm or 6mm. If the cable is 10mm or 6mm I may be able to change it to a 40a or 45a mcb depending on installation methods. Going to see if they got any certificates to look through.

I would be looking at changing the garage board to accommodate RCBOs and a SPD. But then those MCBs that aren’t labeled in the garage board could be spares. So I may be able to shift things around and retrofit a main switch, SPD and rcbos instead of replacing it, probably be easier to replace I’ll see

The thing I’ve been wondering about is load management. If the garage supply cable is only adequate enough to handle a 32A supply, can I still install a charger but put a limit on the EV charger so that the incoming garage supply cable can handle it rather than having to run a new cable to the garage???

Looking at the main CU there seems to be an electric cooker, immersion heater, and central heating circuit. So does the entire installation need to have a ct clamp for load management???

Which EV chargers would you recommend??
 

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CT clamp should go on L tail before meter........Which EV charger installer courses have you done and got a cert for as you will prob need these to commission the charger once installed, so which ever one you have done should be the make you are fitting........also stay away from existing board and fit an independent for install
 
CT clamp should go on L tail before meter........Which EV charger installer courses have you done and got a cert for as you will prob need these to commission the charger once installed, so which ever one you have done should be the make you are fitting........also stay away from existing board and fit an independent for install
From vids I’ve seen they go in the CU on the L tail or outside the CU but after the meter (tail entering CU).

I’ve only done the city and guilds EV course which is 2919 I think? Didn’t know you need to do the course for the EV chargers themselves to commission etc, wouldn’t it just be pretty standard commissioning? Same as all the other EV chargers?
 
Sorry my bad yes after meter...really shouldnt jump on forum so late.....Some manufacturers will only let you commission them if your registered with them
 
This potential client seems to be making progress in terms of being interested in proper chargers and answering my query questions. I have also contacted BG sync EV and they have advised that if the CT clamp route on the meter tails is too much hassle or not ideal then load can be managed to limit the current/power output of the EV charger if I do a full load assessment on the house with a current clamp meter. The clients car battery is only 15-16kw so I can limit the charger quite a bit.

My plan is to change the garage CU over for a Fusebox with a SPD and with 6 useable ways as only 3 of those ways are actually being used. + 1 will be for EV and another 2 spare.

Issue I’ve noticed…

Looking back over the pictures the earthing arrangement is a TNCS/PME. The EV charger I’ll be installing will have open PEN fault device.
But what about the rest of the garage being on the TNCS/PME supply?
Also because I’ll be changing the CU I’ll be responsible for the earthing of it now right? Would I need to install an earth rod?
 

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