What problem do you think might arise?

(That outbuilding will need to be pretty well ventilated.)

Thanks Chris

That did occur to me as six different ASHP's going would pass a lot of air, I was more concerned about external influences and back feeds if a fault were to occur.

Well it wll need to be very clear (contractually) who maintains the cables that are made live or isolated from the flat end, and yet are by the sounds of it routed outside and are accessible to all. Rather like building network wiring it will need to be resistant to casual tampering - who is responsible if it gets vandalised and then someone else gets a shock , for example.

Armour and steel trunking are your friends....This is no worse than flat specific outside lights, sockets or car charging, all common thee days, but it needs to be very clear who does what and who repairs and protects what.

At the equipment end more than usual care over labelling, and also isolation, maybe indicator lamps and things to avoid relying on turning off from inside flat one and accidentlayly opening the live heat exhhanger for flat two sort of accidents.

Interconnection of earthing may or may not become a concern. -If all the flats really share one big incomer it probably isn't really.

Mike

I understand your concerns - the arrangement certainly fails on the 'least astonishment' principle. But having multiple supplies in the same area isn't unknown in the broader sense - in many critical situations (e.g. life support or data critical systems) it's very usual to have duplicated independent supplies (some with UPSs that stay hazardous live even when every upstream isolator is fully open), so there's not going to be any fundamental regulation to simply prohibit this sort of thing in principle. Going back a few years it was common to have off-peak storage heaters on a completely different DNO supply within a home (well same cut-out but separate metering and separate CUs and everything else downstream) and people got used to that. So it's really down to being clear about what goes where (and is fed from what) - so lots of clear labelling and things like tidy distinct cable runs and general layout could help too.

    - Andy.

Thanks for your replay and yes places like hospitals have NPS, EPS and UPS supplies and a domestic dwelling can have an off peak supply but even in these circumstances the final circuits remain within the boundary of the customers property, I the situation I am describing final circuits are leaving the customers property and going into common areas.

Alan Gray said:

I the situation I am describing final circuits are leaving the customers property and going into common areas.

How would you feel about a parking space (for 2 cars) between two adjacent properties with 2 adjacent EVCPs?

Normally EVCP including a vehicle which may be plugged into it must be at least 2.5M from any other supply or extraneous metal work bonded to a LV PME, would that include another EVCP fed from another supply I would think so, I believe if the EVCP is supplied by from an O-PEN device it helps with the proximity of 3rd party supplies.

Alan Gray said:

would that include another EVCP fed from another supply I would think so

That depends on whether the other supply has the same earthing system - so two EV's fed from two different buildings supplied from the same TN-S private network on a large site might be OK, but two vehicles fed from two independent electrical installations with separate supplies perhaps not.

The relevant Regulation to consider is 411.3.1.1 (particularly 2nd paragraph)

OK, if you have a parking space between two buildings and the EVCPs are on the sides of the houses, they might be 5.0 m apart. On the face of it, that is compliant, but what is the situation when both neighbours have their EVs plugged in?

Leaving aside the question of "why would you?", of greater concern is that the cables could be unwound and one plug held in each hand.

This is the situation which recently cropped up here.

Chris Pearson said:

EVCPs are on the sides of the houses, they might be 5.0 m apart.

The IET CoP recommends the "simultaneous contact assessment" is done with respect to the EV not the charging point.

You can, from there, reach your own conclusions ... All I could say at this point is that, per Reg 411.3.1.1, ADS requirements would not be met ... so an alternative means of protection against electric shock (to ADS) is the only option.