Voltage drop and calculation

[Davidbear]

Air compressor. Single phase 240v 17.8amps 150f run of wire run inside of a shop. What size wire and voltage drop and breaker should it be ran on?

 

[charlie b]

How about sharing your answer, before we work it out for you?

 

[Davidbear]

I have a guess that it trying too learn something new. 25 amp breaker number 6 wire. Seeing how other people do calculations just learning.

 

[charlie b]

You didn't say whether this was single phase or three phase. My calculation tells me you can stay below 2% VD if you use #10 wire for a three phase system or #8 wire for a single phase system. This assumes copper wire. I agree with a 25 amp breaker.

 

[Davidbear]

Single phase.

 

[Davidbear]

Thank you.

 

[Besoeker3]

• Multiply current in amperes by the length of the circuit in feet to get ampere-feet. Circuit length is the distance from the point of origin to the load end of the circuit.
• Divide by 100.
• Multiply by proper voltage drop value in tables. Result is voltage drop.

Our cable tables per BS7671 give as mV/A/m. The m being metres. Seems simple enough.