Air con blowing 20a MCB a few weeks into box change in shop/commercial

[Pete999]

Not knowing much about A/C when we installed supplies to these outside units the A/C guys lashed in (sorry installed)small flexes to the indoor unit is there not internal fuses protecting these?

On SP units the compressor (outside) unit provide a SP supply plus control wiring, usually protected at the outdoor unit,

 

[The Ghost]

What is the distance fro the inner unit to the outside unit?

20m I guess, and yes I was going to calculate R1/R2 but thought no there is nothing like measuring it physically. The SWA is 2.5m² 3 core. The control cable coming back is possibly 1.5/2.5 at a guess.

 

[The Ghost]

The shop should have got access for you originally so that you could have tested prior to energising.

Beleive me when I say access was/is impossible until the guy upstairs lets me in.

 

[Toneyz]

How do you know by putting a 32A MCB complies if it is only PVC SWA it's borderline.

 

[plugsandsparks]

On SP units the compressor (outside) unit provide a SP supply plus control wiring, usually protected at the outdoor unit,

Pete999, as mentioned previously, i am a/c refcom certified installer / maintainer. I mentioned the air off simply for the OP to stick his hand near it perhaps with a thermometer, not start to be a refrigeration engineer, politely you have some knowledge of a/c but its either out of date or you have not experienced the full spectrum. Modern systems manipulate pressures and have quite robust protections in place, air off is very reliable. Many systems now are VRF the indoor unit is not powered from the outdoor unit, just saying

 

[Pete999]

Pete999, as mentioned previously, i am a/c refcom certified installer / maintainer. I mentioned the air off simply for the OP to stick his hand near it perhaps with a thermometer, not start to be a refrigeration engineer, politely you have some knowledge of a/c but its either out of date or you have not experienced the full spectrum. Modern systems manipulate pressures and have quite robust protections in place, air off is very reliable. Many systems now are VRF the indoor unit is not powered from the outdoor unit, just saying

So if it's a normal cassette type A/C split unit as they used to be called where do they pick up their supply from?

 

[Pete999]

Pete999, as mentioned previously, i am a/c refcom certified installer / maintainer. I mentioned the air off simply for the OP to stick his hand near it perhaps with a thermometer, not start to be a refrigeration engineer, politely you have some knowledge of a/c but its either out of date or you have not experienced the full spectrum. Modern systems manipulate pressures and have quite robust protections in place, air off is very reliable. Many systems now are VRF the indoor unit is not powered from the outdoor unit, just saying

So if it's a normal cassette type A/C split unit as they used to be called where do they pick up their supply from? Oh and in addition I don't, never have described myself as an A/C expert, I was just passing my limited knowledge on to someone who has less experience than me, by the way it was never mentioned that the system was a VRF type system, just saying.