Air conditoning wiring help

[benlovesnuk]

Hi

 

I have a circuit mcb 25 amp for 3 sockets only, that is basically for the fridge freezer. Could I come off this for a 9000 btu, the wire is 2.5mm or not advisable?

 

Thank you for any help

[Crossy]

A 9,000 BTU A/C will draw around 900 Watts (about 4 Amps) when the compressor is running.

 

No problem load wise adding it to a lightly loaded outlet circuit if it's wired in 2.5mm², put a plug on it and you're good to go.

 

You shouldn't have a breaker over 20A on 2.5 so it would be wise to swap that 25A out.

 

If it's practical I would still run a dedicated circuit but it's not essential.

[benlovesnuk]

On 9/9/2018 at 11:05 PM, Crossy said:

A 9,000 BTU A/C will draw around 900 Watts (about 4 Amps) when the compressor is running.

 

No problem load wise adding it to a lightly loaded outlet circuit if it's wired in 2.5mm², put a plug on it and you're good to go.

 

You shouldn't have a breaker over 20A on 2.5 so it would be wise to swap that 25A out.

 

If it's practical I would still run a dedicated circuit but it's not essential.

HI, Thanks for that. I have the option of a dedicated circuit but its 4mm on 25 or 32 amp breaker, but I wanted to try and use this for electrical heater 6KW (multi) elsewhere. So if I can just come of the dedicated fridge circuit with no ill affects and I just have to swap out the breaker, I would prefer this.

 

On a side note, I noticed that the other Ac unit I have, 15k btu, has live + neutral to the consumer, but no earth. Ive managed to change everything else but this I have not as I have to remodel this room and will be getting it taken down shortly. When I go to put it back where should the earth go? is there a point on the inside unit? I did get a static or electrical shock from the compressor when it was on, so should i just earth this with a ground stake into the earth outside also?

 

Thank you again for your help

 

Regards

[bankruatsteve]

You could swap the breaker but it's not necessary.  Over-current will not be an issue as you described and either will trip on short circuit immediately.

 

The AC installers I have had just ignore the ground or drill a hole in the concrete and jam the ground wire in.  It's probably nothing to worry about but if you do run a ground there should be an identified ground screw on the chassis somewhere.