Check mate!

[PeterW]

  On 20/02/2019 at 21:39, JSHarris said:

I find it hard to understand why they are being sold for £500 or so

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Thats because it’s got a CE mark on it... which stands for Charge Extra...

[Jeremy Harris]

  On 20/02/2019 at 22:04, PeterW said:

 

Thats because it’s got a CE mark on it... which stands for Charge Extra...

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You'll probably laugh, but it seems that almost all charge points that have been installed over the past few years aren't in compliance with the regs!  A condition of the OLEV grant is that they comply with an IET guidance note (now swept up into section 722 of BS7671) that requires all charge points to be installed as a TT island, with either a Type B RCD, or with a built-i means to detect earth leakage faults in the presence of a DC component greater than that which a Type A RCD will deal with (>6 ma DC).  None I've seen comply.  Mine is OK as this rule only applied to OLEV grant funded charge points until the 18th Ed came into force, and mine were installed under the 17th, 2nd Amendment.

[Mr Punter]

  On 20/02/2019 at 22:12, JSHarris said:

 

You'll probably laugh, but it seems that almost all charge points that have been installed over the past few years aren't in compliance with the regs!  A condition of the OLEV grant is that they comply with an IET guidance note (now swept up into section 722 of BS7671) that requires all charge points to be installed as a TT island, with either a Type B RCD, or with a built-i means to detect earth leakage faults in the presence of a DC component greater than that which a Type A RCD will deal with (>6 ma DC).  None I've seen comply.  Mine is OK as this rule only applied to OLEV grant funded charge points until the 18th Ed came into force, and mine were installed under the 17th, 2nd Amendment.

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I have had 7 charge Rolec BasicCharge pedestals installed on residential driveways without TT islands, as there was too great a risk of damaging other services where they were fairly congested underground.

 

Is the risk just to do with a neutral fault on the network that is undetected?

[Jeremy Harris]

  On 21/02/2019 at 10:21, Mr Punter said:

 

I have had 7 charge Rolec BasicCharge pedestals installed on residential driveways without TT islands, as there was too great a risk of damaging other services where they were fairly congested underground.

 

Is the risk just to do with a neutral fault on the network that is undetected?

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The primary concerns seem to be both that a neutral fault may not be reliably detected and that the inherent DC component from the switched mode vehicle charger may DC block a Type A or Type AC RCD, so preventing it from tripping if there's a fault.

 

The Rolec has a re-badged Chinese 40A RCBO of unknown parentage or specification as its protection device (others have tracked the OEM down to several on Alibaba).  These seem to be Type A, not Type B.  There have been quite a few recorded failures of the early RCBOs, with them overheating and burning out internally.  I believe Rolec have now changed to a different supplier, and changed the colour of the lettering on the new RCBOs to green (from blue and black).

[ProDave]

  On 21/02/2019 at 10:21, Mr Punter said:

 

Is the risk just to do with a neutral fault on the network that is undetected?

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Yes.

 

With a TNCS / PME supply, neutral and earth come in on the same conductor,  It is not unknown for the outer neutral conductor to fail.  If that happens and there is a load connected, the "earth" could float up to L potential.  Very bad news for someone standing on the ground next to it and touching it.  Same reason caravans should be on a TT earth.

[Mr Punter]

@JSHarris & @ProDave I know it is off topic but this is one of the charge points. Would it be unsafe to use?

 

[Jeremy Harris]

@Mr Punter, it's as safe as any other, and has the newer green RCBOs fitted, which were replacements for the ones that used to regularly burn out in the earlier models. 

 

My two charge points just have DP Type A RCBO protection, as when I installed them that was all that the regulations required.  The additional protection offered by a TT island, with DC capable RCD functionality, didn't become part of the regulations until this year, when the 18th Ed came into force.  Before that, there was an IET guidance note that referred to having a DC-capable RCD protection device, with a TT island, but that was only mandated for installations that were partly paid for by an OLEV grant.  Any installation that wasn't grant funded didn't have to comply with the IET guidance note.

[Mr Punter]

Thanks @JSHarris that is good to know, as I prefer not to need to add a caveat saying "The charge point will only be compliant if you install a TT island and you will be responsible for any damage to underground services."