SWA protection to car charger query

[sydsparrow]

Qualified electrician has installed Zappi car charger outside house. Grid incoming goes to DNO cutout then to SPD then to meter then to henley block then to RCCB then to SWA cable out wall and to charger mounted on outside wall (about 4m length SWA). I just learnt that RCCB gives no overcurrent protection. It is a Lewden jobbie marked 'RCCB 40A'. There is no MCB.

My thinking is there is no overcurrent protection for the SWA cable leaving the building. Is that ok and within regs? Install was a couple of months ago. Photos below - RCCB is inside the grey box with the yellow label on it.

SWA is not metal glanded at either end and the armour is not connected at the house end (it might be at the charger, I haven't looked inside). SWA cable is Doncaster EV-Ultra (so has the ethernet cable). I am interested in whether the SWA armour needs to be a) connected to earth and b) connected at house end or just charger end. Grateful for your thoughts.

 

[loz2754]

You're right that the EV cable is not protected against overcurrent. Also that the swa cable should be properly terminated using an swa gland, at least at the supply end.
What you may not realise is the RCCB is a type AC, and should be a type A at least.

 

[sydsparrow]

You're right that the EV cable is not protected against overcurrent. Also that the swa cable should be properly terminated using an swa gland, at least at the supply end.
What you may not realise is the RCCB is a type AC, and should be a type A at least.

I thought AC RCD was ok with a Zappi as it has internal DC leakage capable RCD (along with PEN fault detection)?

I had assumed the SWA was earthed at Zappi end. Now doubting that. Sure enough, just looked inside Zappi, no connection at either end of SWA.


It really pees me off when I could have done this myself to regs but, no, I have to get a 'qualified' electrician to install it. Next electrician that says anything bad about an amateur I may punch in the face. (I know that there are some excellent and competent qualified electricians around.)

So, what recourse do I have now if the electrician that installed this refuses to come and correct his work to regulation standards? Are there actual regulations that state that:
a) An outside cable run should have overcurrent protection at source.
b) An outside SWA should have armour earthed adequately?

Should I also have been given some kind of certificate from the electrician who did the work?

 

[loz2754]

Regarding RCDs for EV charging equipment, regulation group 722.531.3 applies. RCD type shall be type A, type F, or type B.

Chapter 43 deals with overcurrent protection, 430.3 says a protective device shall be provided to break any overcurrent in the circuit conductors. As you point out, an RCCB does not provide this function. So the only overcurrent protection provided in this case is the main cutout fuse.

The correct way to install SWA cable connections is not specifically mentioned as such in the regulations. However, 134.1.1 talks about good workmanship, and taking into account the manufacturer's instructions.
Why bother using SWA in the first place if there is no intention of connecting the armour to earth?

 

[brianmoooore]

Should I also have been given some kind of certificate from the electrician who did the work?

Yes, but it would be either incorrectly filled out, or marked "unsatisfactory".
SWA should have overcurrent protection at source, and the armour should be earthed. It is only required to be earthed at either end, not both, when not used as the cpc, although it's good practice to earth at both ends, and if this is not possible, to provide the sole earthing at the source end.
RCD protection is not required for correctly installed SWA, so if the charge point has built a built in RCD and is suitable for connection to a TNC-S supply, the job can be made good by glanding the SWA properly an replacing the RCD at source with a SP + N MCB.

 

[James]

Qualified electrician has installed Zappi car charger outside house. Grid incoming goes to DNO cutout then to SPD then to meter then to henley block then to RCCB then to SWA cable out wall and to charger mounted on outside wall (about 4m length SWA). I just learnt that RCCB gives no overcurrent protection. It is a Lewden jobbie marked 'RCCB 40A'. There is no MCB.

My thinking is there is no overcurrent protection for the SWA cable leaving the building. Is that ok and within regs? Install was a couple of months ago. Photos below - RCCB is inside the grey box with the yellow label on it.

SWA is not metal glanded at either end and the armour is not connected at the house end (it might be at the charger, I haven't looked inside). SWA cable is Doncaster EV-Ultra (so has the ethernet cable). I am interested in whether the SWA armour needs to be a) connected to earth and b) connected at house end or just charger end. Grateful for your thoughts.



View attachment 103829
View attachment 103828

EV .Ultra is not swa, it has no armour. It is a tough sheaf cable.
therefore it can’t be earthed with a brass gland.

 

[brianmoooore]

EV .Ultra is not swa, it has no armour. It is a tough sheaf cable.
therefore it can’t be earthed with a brass gland.

The stuff in the zappi pic. appears to have the ends of trimmed off armour visible.

 

[James]

EV-Ultra Cable 6.0mm 3 core + CAT5E Data PVC Tuff-Sheathed - Cut to Length | DC (EV-ULTRA3C6.0CAT5)

defiantly no swa.

edit, after looking at pic again, that looks like it is swa.

 

[westward10]

The cable in that pic is SWA.

 

[James]

Looks like you can get it with swa

EV-Ultra SWA Cable 3 Core 4.0mm + Cat5 Enhanced | DC (EV-ULTRA3C4.0CAT5SWA)

 

[sydsparrow]

Regarding RCDs for EV charging equipment, regulation group 722.531.3 applies. RCD type shall be type A, type F, or type B.

Chapter 43 deals with overcurrent protection, 430.3 says a protective device shall be provided to break any overcurrent in the circuit conductors. As you point out, an RCCB does not provide this function. So the only overcurrent protection provided in this case is the main cutout fuse.

The correct way to install SWA cable connections is not specifically mentioned as such in the regulations. However, 134.1.1 talks about good workmanship, and taking into account the manufacturer's instructions.
Why bother using SWA in the first place if there is no intention of connecting the armour to earth?

Thanks, Loz. The charger has the DC RCD action built in so am thinking dedicated (i.e. not shared) Type AC 30mA (2-pole) upstream would do ok:

https://support.myenergi.com/hc/en-gb/articles/4403885493265-zappi-6mA-DC-protection-to-IEC-62955

Regardless of whether armour is used as CPC, it still provides physical protection of the inner cores which is pretty useful on a wall where things could scrape against and scrape off plastic insulation, exposing conductors.

As well as the reg you pointed out, I found regs regarding overcurrent protection ref car chargers:

https://electrical.------.org/media/2337/amendment1_read-only_final.pdf

722.533.101

Because connecting the SWA armour to earth is not mentioned in the regs, I don't think I can force the electrician to connect it. Like you say, I certainly would have done at the house end, but I am merely an unqualified amateur.

 

[brianmoooore]

There certainly ought to be a SWA available for EV use. You don't really want to have to fit a RCD at source if the charge point has one built in.

 

[sydsparrow]

This install uses the SWA armour type.

Ooh, but now I see that a number of people say that the 'sheath' on top of the armour of SWA cable should not be considered 'insulation' and, therefore, the armour should be considered exposed conductor and so needs to be earthed. <pulling hair out emoji>

 

[loz2754]

The charger has the DC RCD action built in so am thinking dedicated (i.e. not shared) Type AC 30mA (2-pole) upstream would do ok:

The regulations (quoted in my previous post) state specifically that the RCD should be type A or better. Type AC is not permitted for an EV charge point.

If the charge point does not have RDC-DD (residual DC detection device) protection, then a type B RCD is required, either in the charge point, or upstream.

The built in RDC-DD is not an RCD but it's a different component, designed to disconnect when DC leakage is detected.
Furthermore, although Zappi charge points do in fact have an on board RCD, it is not yet recognised in any standards, and on the Zappi training course, I was told to always install a type A RCD upstream in all cases. (This will probably change, and may already have changed).

 

[loz2754]

There certainly ought to be a SWA available for EV use. You don't really want to have to fit a RCD at source if the charge point has one built in.

EV Ultra is available in SWA and tough sheath.
Hypervolt also have similar cables.

 

[loz2754]

replacing the RCD at source with a SP + N MCB.

Why SP + N? The SWA only needs SP protection surely?
The RCD in the charge point will be double pole.

 

[brianmoooore]

Why SP + N? The SWA only needs SP protection surely?
The RCD in the charge point will be double pole.

DP isolation for the cable.

 

[loz2754]

DP isolation for the cable.

Of course, I'd forgotten it was fed directly off the Henley blocks. Doh

 

[brianmoooore]

Also the existing neutrals need to be connected together somehow, and a device that is physically similar to the RCD would be the easiest to fit.

 

[sydsparrow]

The regulations (quoted in my previous post) state specifically that the RCD should be type A or better. Type AC is not permitted for an EV charge point.

If the charge point does not have RDC-DD (residual DC detection device) protection, then a type B RCD is required, either in the charge point, or upstream.

The built in RDC-DD is not an RCD but it's a different component, designed to disconnect when DC leakage is detected.
Furthermore, although Zappi charge points do in fact have an on board RCD, it is not yet recognised in any standards, and on the Zappi training course, I was told to always install a type A RCD upstream in all cases. (This will probably change, and may already have changed).

I appreciate you pushing this point, Loz. An ammendment (722.531.3.101, BS 7671:2018, Amendment 1:2020) starts with, "Except where provided by the EV charging equipment..." in relation to requiring Type A, B, F etc.

BS 7671 -722 Amendment 1: RCDs & RDC-DDs - Electrical Contracting News (ECN)

By Chaz Andrews, Technical Manager of Doepke UK Effective RCD protection for electric vehicle (EV) sockets relies on the correct ...

electricalcontractingnews.com

From the manufacturer:
"The single phase zappi should be connected to a 230V/240V nominal AC supply. The supply should run from a dedicated 32A circuit breaker. The 3 phase zappi should be connected to a 400V, 4 wire, 3 phase supply. The supply should run from a dedicated 3 pole 32A circuit breaker. We recommend the use of curve B circuit breakers. The zappi features an integral 30mA Type-A RCD with 6mA DC leakage detection in accordance with IEC 62955. Local wiring regulations should consulted to confirm whether an additional upstream RCD is also required."

Good cop-out statement at the end regarding local regs.

It's an appalling system where regs are not allowed to be reproduced/printed/copied in any detail making it very difficult for a consumer to know whether or not the paid 'qualified' electrician has done their job properly or not, until it is too late. These failings lead to a lack of respect for the whole industry from the consumer. Not one of you have suggested reporting this guy to his regulatory body. I am currently trying to persuade him that RCCB does not give overcurrent protection. His comment: "The zappi will never pull no more than 40A so will never go over that amount, plus the rccb is limited to that as well so it can not allow more than 40A being pulled".