Air Conditioning Electrics

[Legend139]

So I’m installing a 3.5kw Samsung air conditioner / heatpump for my main bedroom.

Power draw is around 1kw and 4.2a ish max for both heat and cooling. Plan on running this off a fuse spur as getting access to the consumer unit would be extremely costly pulling the flooring up downstairs as it’s literally at the other side of the house, which isn’t an option.

Currently I have an FCU in the living room on the side where the outdoor unit for the AC will be going, this is where the old electric fireplace was which is now removed. The FCU is part of the ring main (inside the house) and not spurred from a socket.

All circuits are rcd protected, and the downstairs sockets which have very minimal load as the kitchen has a dedicated circuit.

Now my question is, how would be best to terminate armoured cable to the FCU that’s inside the house? It would be nice to just drill out at an angle and run the armoured 1.5m ish max clipped to side of the house and into a 20a isolator switch. Would this even need armoured cabling??

I know I could use T+E through the wall and sleeve into a wiska box and then terminate the armoured cabling to that, then go to the 20a isolator switch. Would like to avoid this if possible? Is there anyway to do it?

Thanks
Connor

 

[Adam_151]

I'd do it in NYY-J not SWA if its just out the back of a spur to an isolator. If you do use SWA, remember you must ensure that the armourings are earthed.

I'd also make sure the RCD protection is not 'AC' type, you don't want to be adding inverter drives (as almost all A/con is these days) to a socket circuit supplied from a 'AC' type RCD

 

[Legend139]

Hi Adam,

Thanks for the reply, will have to double check I’m sure it’s a type b been a while since I checked tbh.

Yes I’m aware armoured must be earthed, just like having a clean install. The isolator is going to be meter or so away from the FCU would running NYY-J be okay? Was always lead to believe anything outdoor had to be armoured or in some sort of mechanical protection etc?

Thanks
Connor

 

[Legend139]

Having a quick read online, I’ve seen someone suggest a galvanised trouser box which would be a lot smaller and conspicuous than a wiska box, has anyone ever terminated to one and what would they need?

 

[EFLImpudence]

Was always lead to believe anything outdoor had to be armoured or in some sort of mechanical protection etc?

Nope - not unless it needs to be for other reasons.

 

[davelx]

Hi Adam,

Thanks for the reply, will have to double check I’m sure it’s a type b been a while since I checked tbh.

Yes I’m aware armoured must be earthed, just like having a clean install. The isolator is going to be meter or so away from the FCU would running NYY-J be okay? Was always lead to believe anything outdoor had to be armoured or in some sort of mechanical protection etc?

Thanks
Connor

Unlikely to be a type B RCBO - they cost a fortune and only installed in certain situations. Almost certaily the type B refers to the MCB curve, not the RCBO part. There should be a symbol - to indicate the RCBO type - a rectangle with just a wavy line is type AC. Type A has a wavy line and a pulse/squarish wave underneath it. Post a photo if you're not sure.