Power to ASHP

[Moonshine]

How do you get power from the inside to outside to an ASHP isolator box.

My thoughs are its as simple a running a cable from the ceiling behind trucking / dot and dab, drill a hole in the external wall feed the cable through the wall to the isolator switch.

Is that too much of a ludite way or do i need a conduit or something else?

[Nickfromwales]

If the circuit is fed via an earth protected device eg RCD > MCB / RCBO then you can run cables in a shallow chase, if in a safety zone, or chased ~50mm deep if not in a safety zone. 
Thats the standard observed by most sparks. 

[Marvin]

Hi @Nickfromwales

 

Just out of interest, our ASHP manual specifies an MCB/RCBO but a Type C Would your comments above still apply?

 

M

[PeterW]

30 minutes ago, Marvin said:

Hi @Nickfromwales

 

Just out of interest, our ASHP manual specifies an MCB/RCBO but a Type C Would your comments above still apply?

 

M

Yes because the Type C is purely that it has a higher peak curve so when a motor kicks in then the device won’t trip. Most inverter drives don’t actually need it but the MIs still seem to reference them.  

[Moonshine]

On 30/07/2022 at 16:25, Nickfromwales said:

If the circuit is fed via an earth protected device eg RCD > MCB / RCBO then you can run cables in a shallow chase, if in a safety zone, or chased ~50mm deep if not in a safety zone. 
Thats the standard observed by most sparks. 

 

The ASHP going on the external wall as below, but the internal stud work wall isn't going in, so no safety zone.

 

It looks like its going to need a 50mm chase down from the joist level, or i could take it out at joist level, and have an ugly conduit on the external wall down to the ASHP.

 

The screed isn't down yet, could an option be to put the conduit in the insulation below the screed? 

 

[ProDave]

Just to be clear, if you are proposing to run a cable down the wall and out to the isolator, it is ONLY a safe zone if there is some electrical accessory on the inside of the wall to create the safe zone.  e.g. if there was a socket on the wall directly below where the ASHP cable exits, then it would be a safe zone.

 

If you really want to run the cable down then out, why not fit a 13A socket directly below the cable exit and you have created your safe zone, and an extra 13A socket is never going to be "too many"  Far easier to fit an extra socket than a deep chase in the wall all the way down.

[Nickfromwales]

44 minutes ago, Moonshine said:

The screed isn't down yet, could an option be to put the conduit in the insulation below the screed? 

@ProDave

Is a conduit in insulation subject to de-rating?

[Moonshine]

59 minutes ago, ProDave said:

Just to be clear, if you are proposing to run a cable down the wall and out to the isolator, it is ONLY a safe zone if there is some electrical accessory on the inside of the wall to create the safe zone.  e.g. if there was a socket on the wall directly below where the ASHP cable exits, then it would be a safe zone.

 

If you really want to run the cable down then out, why not fit a 13A socket directly below the cable exit and you have created your safe zone, and an extra 13A socket is never going to be "too many"  Far easier to fit an extra socket than a deep chase in the wall all the way down.

 

That is what i am trying to do (or come up with a suitable alternative).

 

I was relying on and thoughts there was a vertical safe zone of 150mm of the angle formed by two walls (external wall and internal stud) but now this internal wall may not be here and no save zone in the corner.

 

The extra socket  internally is a great idea to create a new safe zone vertically
 

@ProDavewhat other alternative / easier way is there to get power out to the ASHP / external wall socket?

Edited August 1, 2022 by Moonshine