EVSE and RCD Questions.

[strider6]

I'm obviously still new and learning about what I can and cannot do, but essentially I want to install an EVSE at my own house for an electric van, I intend to run a 6mm T&E in surface trunking/clipped direct, through a drilled hole in the wall and then out a wiska box through some flexible conduit into an EVSE of my choice.

Currently I'm looking at the brand new Project EV Apex untethered charger, it has a type A RCD built in, I know if the cable is buried less than 50mm from the surface it needs to be RCD protected, but does surface cabling have this same requirement (even being T&E) or can I avoid the selectivity issue (and mainly the extra cost of procuring RCBOs for my obsolete CU) of doubling up the RCDs and just install a 32a MCB and DP 45a cooker isolator on the wall where I drill through? Or do I need to run it in SWA for 2 to 3 times the the price?

 

[mainline]

I'm obviously still new and learning about what I can and cannot do, but essentially I want to install an EVSE at my own house for an electric van, I intend to run a 6mm T&E in surface trunking/clipped direct, through a drilled hole in the wall and then out a wiska box through some flexible conduit into an EVSE of my choice.

Currently I'm looking at the brand new Project EV Apex untethered charger, it has a type A RCD built in, I know if the cable is buried less than 50mm from the surface it needs to be RCD protected, but does surface cabling have this same requirement (even being T&E) or can I avoid the selectivity issue (and mainly the extra cost of procuring RCBOs for my obsolete CU) of doubling up the RCDs and just install a 32a MCB and DP 45a cooker isolator on the wall where I drill through? Or do I need to run it in SWA for 2 to 3 times the the price?

I think in most cases that you need a DP type A rcd upstream of the charging point.
RDC-DD does not provide additional protection at 30ma

 

[strider6]

I think you will find that you need a DP type A rcd upstream of the charging point due to the one in the ev point not providing the proper protection.

The datasheet for the charger quotes "Integral Type A RCBO / AC 30mA / DC 6mA", is this not good enough?
I know that double pole isolation is needed and that the feed should obviously be fused correctly, and maybe it's a stupid question but why would they include it if it wasn't providing proper protection? Or am I missing something else here maybe?

 

[James]

In my opinion, the built in rcd will protect the load(car)
however you still have to ensure that the cable is correctly protected and thought has gone into the possible requirement for a pen failure.

 

[strider6]

In my opinion, the built in rcd will protect the load(car)
however you still have to ensure that the cable is correctly protected and thought has gone into the possible requirement for a pen failure.

I'm on TN-S, so pen fault isn't needed, though it is built into the charger. I intend to run as T&E totally surface in trunking (apart from where it will be drilled in the wall more than 50mm from the surface) which from my understanding negates the need for an RCD due to it not being buried less than 50mm and also being mechanically protected? I could run it in SWA but that would cost a lot more and require larger trunking, and I'd like to avoid that if I can.

 

[James]

6mm (3 core) swa £4 per m
6mm twin and E £2 per meter
if this is a 20m run (guess) then the cost difference is £40, just do it in swa and everything is good, no messing with trunking etc. easy job.

 

[davesparks]

I know if the cable is buried less than 50mm from the surface it needs to be RCD protected, but does surface cabling have this same requirement

There is currently no requirement for surface mounted cable, or cable in surface mounted trunking/conduit to have additional protection by 30mA RCD

 

[DefyG]

My thoughts are same as #7 but why into wiska box and then flexi to charge point?

Why not go straight in back of charger?, be a neater install.

 

[strider6]

My thoughts are same as #7 but why into wiska box and then flexi to charge point?

Why not go straight in back of charger?, be a neater install.

This charger doesn't support rear entry from the looks, only bottom entry, hence that.

6mm (3 core) swa £4 per m
6mm twin and E £2 per meter
if this is a 20m run (guess) then the cost difference is £40, just do it in swa and everything is good, no messing with trunking etc. easy job.

Unless they make a white sheathed SWA, I would still need to run it in trunking (but with SWA, larger trunking) otherwise it will look awful, I'd sooner spend that difference in money on sourcing the DP RCBO for my CU.