Level of risk to tenants for heat pump on a shared type A rcd

If you know (or suspect) that there's a defect which may give rise to danger, and then someone gets hurt, what will be the excuse?

The point of an EICR is to check whether there are any issues that haven't been identified and in so doing provide an expert's opinion on whether the installation remains servicable, not to provide a reason to delay maintenance.

The thing is I don't fully know the risk (if any) BS7671 does not mention heat pumps neither does best practice guide 4. The latter suggest that wrong rcd type on an evse could be a C3.

Im hoping they will gain a new entry in special locations in the future.

This will affect many properties,the developer states they were installed as per the regs at the time.

The regs are not retrospective and it states something installed to an earlier edition could still be safe.

Our contractor initially gave a C2 but niceic advised them to change to a C3 during a recent inspection.

If it was my design I would specify a type B HP, I have been informed these were not available at the time and I'm not sure these even have a standard?

I would specify a type B HP

From what I can gather, the "B HP" types differ from more conventional types in that they're less sensitive to high frequency components of the residual current (e.g. min threshold of 150 mA for frequencies over 1 kHz, even for what's nominally a 30mA device) - so as I see it specifying a "B HP" type is in part to reduce nuisance tripping, rather than improve safety from a shock perspective. So if it's already installed and working satisfactorily, you're probably OK on that score.

Next question is whether you'd need a B type rather than a A type - that's harder to answer - d.c. currents (e.g. over 6mA) can certainly blind an RCD - but I suspect a HP is less risky than say an EV on that score - there being no big battery that could be connected to the a.c. supply by a fault in the electronics and no deliberate d.c. run along c.p.c.s as a pilot signal.

    - Andy. 

I would specify a type B HP

From what I can gather, the "B HP" types differ from more conventional types in that they're less sensitive to high frequency components of the residual current (e.g. min threshold of 150 mA for frequencies over 1 kHz, even for what's nominally a 30mA device) - so as I see it specifying a "B HP" type is in part to reduce nuisance tripping, rather than improve safety from a shock perspective. So if it's already installed and working satisfactorily, you're probably OK on that score.

Next question is whether you'd need a B type rather than a A type - that's harder to answer - d.c. currents (e.g. over 6mA) can certainly blind an RCD - but I suspect a HP is less risky than say an EV on that score - there being no big battery that could be connected to the a.c. supply by a fault in the electronics and no deliberate d.c. run along c.p.c.s as a pilot signal.

    - Andy.