daikin fwc07b7fv1b current

[Integrator741]

Hi all,

I am trying to calculate maximum current drawn by daikin air conditioning unit.

On technical sheet it says maximum power is 6.6 kw.

So if I operate the unit at maximum power I draw 6.6/240 amps, don't I?

Now the unit is supplied by 1.5mm flex, which has current carrying capacity of 16 amps.

When I turn the unit on, it's working fine, but something is wrong with speed, because no matter what speed setting I press, the unit doesn't react. So I was thinking could it be the 1.5mm flex that's not giving enough current? Or something wrong with controls?

Thanks.

 

[Harald Kapp]

So if I operate the unit at maximum power I draw 6.6/240 amps, don't I?

6.6 kW / 240 V = 6600 W / 240 V = 27,5 A. No way to operate this unit on a 16 A fuse. Is this a single phase air conditioner or a three phase air conditioner? A three phase unit in delta connection will see sqrt(3)*240 V = 415 V per leg, thus current is 6600 W / 415 V = 16 A which is imho more plausible.

So I was thinking could it be the 1.5mm flex that's not giving enough current? Or something wrong with controls?

Is 1.5mm the diameter, radius or cross sectional area? Note that it is common to label a conductor according to the cross sectional area.
Assuming 1.5 mm is the diameter, this calculator gives a resistance of approx. 0.01 Ω per meter. Double that for a 2-wire cable to get 0.02 Ω per meter. At 25 A (assuming it is a single phase system) thsi is equivalent to 0.5 V voltage drop across each meter of cable or equivalently 0.2 % per meter of cable.
I doubt this voltage drop will influence the operation of the air conditioner. You will see a much higher change in voltage from voltage fluctuations typical for mains.
It is very probably the controller that is not doing its job.

 

[Integrator741]

It's a single phase. 1.5 mm diameter. Distance is not big either.... also it's fed from 13 amp spur, so I think it would have blown the fuse if it was taking that much current. But what can possibly be wrong with controller? All the other functions are fine.