Yet another aircond installation question.

[jack2964]

I am in the midst of adding a small (2-bdrm) out-building for myself with an extra guest room and have been shown these stuff by the 'builder'. Pls. view pics.

Each bedroom has an attached bathroom and will be air-conditioned plus hot water shower.

I have been told by the builder everything will be wired to the CU and all will be fine but I have my doubts.

The bedrooms are tiny (approx 3m x 3m). Having gone through a few of the older threads I think I'll need 2X dedicated aircond breakers 

and 2X hot shower breaker. Please advise. Thank you.

 

[bankruatsteve]

Is the CU dedicated to the outbuilding?  If so, you may as well use the breakers for separate circuits.  Can't see the size of them but 2.5mm2 cable should not exceed 24 amp breaker (normally on 20 amp).  Otherwise, both AC can easily be together on one breaker (unless you need isolation).  The shower units should be on separate circuits and no larger than 4.5Kw.  Larger units would need 6mm2 cable with 32 amp breaker.  Be sure they install GROUND.

[jack2964]

2 minutes ago, bankruatsteve said:

Is the CU dedicated to the outbuilding?  If so, you may as well use the breakers for separate circuits.  Can't see the size of them but 2.5mm2 cable should not exceed 24 amp breaker (normally on 20 amp).  Otherwise, both AC can easily be together on one breaker (unless you need isolation).  The shower units should be on separate circuits and no larger than 4.5Kw.  Larger units would need 6mm2 cable with 32 amp breaker.  Be sure they install GROUND.

Yes the CU is just for this new build and will be grounded. The CU pic isn't too clear but of the 8 breakers on the right half I have 2x C16; 3x C20 and 3x C32 breakers. Would this be sufficient for two airconds and 2 hot showers? 

[bankruatsteve]

Guessing you are stuck with that breaker configuration (can't replace, right?).  If me, I would put the showers on the 32a breakers but again that will require 6mm2 cable.  

 

The AC's could could both go on the 3rd 32a breaker if you don't have another use for it.  (using 6mm2)

 

Edit:  if you don't have 6mm2 cable for the 32a breakers, you could just go with two 2-core 2.5mm2 cables (one for N the other for L) as that would effectively be 5mm2 and good for 32a.

 

Edited July 2, 2017 by bankruatsteve

[jack2964]

25 minutes ago, bankruatsteve said:

Guessing you are stuck with that breaker configuration (can't replace, right?).  If me, I would put the showers on the 32a breakers but again that will require 6mm2 cable.  

 

The AC's could could both go on the 3rd 32a breaker if you don't have another use for it.  (using 6mm2)

 

Edit:  if you don't have 6mm2 cable for the 32a breakers, you could just go with two 2-core 2.5mm2 cables (one for N the other for L) as that would effectively be 5mm2 and good for 32a.

 

Thanks Steve all duly noted. I'll go get some 6mm2 cable.

45 minutes ago, bankruatsteve said:

Is the CU dedicated to the outbuilding?  If so, you may as well use the breakers for separate circuits.  Can't see the size of them but 2.5mm2 cable should not exceed 24 amp breaker (normally on 20 amp).  Otherwise, both AC can easily be together on one breaker (unless you need isolation).  The shower units should be on separate circuits and no larger than 4.5Kw.  Larger units would need 6mm2 cable with 32 amp breaker.  Be sure they install GROUND.

Yes the CU is just for this new build and will be grounded. The CU pic isn't too clear but of the 8 breakers on the right half I have 2x C16; 3x C20 and 3x C32 breakers. Would this be sufficient for two airconds and 2 hot showers?