cold room mains cable and isolator sizing

[wheats8]

Hi,

Im looking to give a quotation for a cold room but abit unsure how to calculate the correct size mains cable required to ensure the job is safe. I know the system needs a 20A breaker but not sure what size cable would be safest to use...also is the ampage of the rotary isolator worked out on the breaker size or the cable size?

Thanks

[cadwaladr]

dont quote for electrics if you are not an electrician,get an electrician to do it.

[r.bartlett]

Hi,

Im looking to give a quotation for a cold room but abit unsure how to calculate the correct size mains cable required to ensure the job is safe. I know the system needs a 20A breaker but not sure what size cable would be safest to use...also is the ampage of the rotary isolator worked out on the breaker size or the cable size?

Thanks

If you are at this level I would take the above advice and save yourself a lawsuit or worse a potential fatality