[NDKR]

Hello, first post here. I have signed up to Pod Point for a home charger and had an email saying they could not run cables under floor through my lounge next to existing cables due to regs. The existing cables are HDMI cables and coax/sky. Does this sound right - it seemed odd to me and I'm not sure what regulation would be broken or what the safety issue would be....?

 

[Tandy0]

It's not due to regs. It's due to idleness, making the excuse of regs.

I suggest you install a draw rope in the route you want, and I'm sure the regs will be relaxed.

 

[Hilltop Dave]

The existing cables are HDMI cables and coax/sky. Does this sound right

AFAIK, if unsheathed mains wires and low voltage (eg HDMI and coax/sky) wires are enclosed in the same conduit or trunking, then the regulations require the low voltage wires to be sufficiently insulated to withstand mains voltage.

If you are just considering the space under floorboards, the mains cable they are installing will need to be sheathed, so there should be no electrical safety reason why it should not share the space with HDMI and coax/Sky cables.

However, they may be worried about any interference induced into the HDMI and coax/Sky cables from the currents and voltages in your proposed charging point supply cable. How far apart could you keep the cables?

 

[NDKR]

I proposed to pod point to put the EV charging cable in the same channelling as the other wires - its quite a wide plastic channel - shown below. The purple ones are HDMI, the 2 brown ones and 1 black are sky/ariel unused (planned to use one of these as a drawstring), the white i think is an alarm wire (or possibly speech dialler), and the thin black wire going up is for subwoofer. I thought the EV cable would be sufficiently shielded so it could sit in the same plastic channel as the other cables...

 

[NDKR]

I had an email back from Pod Point saying the regulation that would be broken is "Proximity of Wiring Systems to other services 528 (528.1 & 528.2) " . If this cant be worked around I am going to have to go back to the drawing board as the meter and CU are in the middle of the house. Maybe if I see if I can fit in a flexible conduit that would work - any thoughts welcome. Does anyone know the diameter of the cable they will install? thanks

 

[dk6780]

Put simply the mains cable cannot share the same conduit without the insulation for all of the other cables being up to the same standard. Clearly the latter is unlikely to be the case and you are not going to change them.
In theory you could pull another smaller conduit through for the new cable (hence subdividing it) but I suspect that you haven't got space. Pod Point may accept sense and allow you to install an armoured cable, but that will be a lot larger diameter (say 16mm diameter) and relatively difficult to take around any bends if they are present as it'll need a diameter of around 450mm if that makes sense.
In answer to your question they will normally fit 6mm^2 twin + earth for a 32 Amp installation which is about 14mm x 7mm across the greatest dimensions and much more flexible than the SWA mentioned above.
I suspect this means back to the drawing board. It is unusual for the incomer to be completely inaccessible - can you not go back out the way it comes in?

 

[NDKR]

Thanks that's helpful info. The incoming supply cable comes up from the floor under the stairs, straight into the fuse and meter. I don't know where to access it before this point - must be buried.

 

[dk6780]

And your ground floor is solid? Do your stairs touch an outside wall? And which way do your first floor joists run - side to side or front to back? Simple rule - If you can't go down go the quickest way out, even if that is via the roofspace.

 

[Hilltop Dave]

Put simply the mains cable cannot share the same conduit without the insulation for all of the other cables being up to the same standard. Clearly the latter is unlikely to be the case and you are not going to change them.

Does this apply if the mains cable is double insulated by its sheath? I can understand it for unsheathed mains wires within conduit or trunking, but if what is proposed would be OK on an open surface, does putting a box round it make it any less safe?. Looking at my 16th Edition regs this is not clear.

One possibility is to use Mineral Insulated Copper Clad cable, which has an earthed outer covering, but this may be difficult to bend round corners.

 

[dk6780]

My understanding is it does, unless the low voltage cables are double insulated. Quite why that is I don't understand.

 

[NDKR]

I think I have enough room to include a flexible corrugated 20mm conduit in the channel, it will probably have to be pulled through at the same time as the cable install. The engineer is coming over next week so can discuss this and alternatives. thanks