huh?????????

[diovol]

im about to wire up my compressor ( from pressure switch to female outlet) which is a 7hp 230volt 80 gallon porter cable model c7550.
When I checked the motor to see what amperage it is it says 23A. The thing i found weird was that the motor to the pressure switch is wired with 12/2 wire..... It is a WEG motor.

Now I bought the compressor used but only 4 months old so im not sure if the motors come wired already and all you have to do is wire the cord to the outlet but when i went to HD and i told the guy what i was using he said i must use 10/2.....

thanks

 

[nehog]

You should be OK on the 12 AWG on the run between the pressure switch and the motor, it's only a few feet. There are some special tables for looking this up (basically called appliance wiring), and as voltage drop over a few feet is not much, wire size can be smaller.

I suppose if you wanted, you could replace it with 10 AWG, I'd recommend stranded (for better vibration resistance) in a flexible conduit.

 

[rockwithjason]

this is a tricky one that trips up many people. the rating on 12ga thhn insulated wire which is the most commonly used wire is actually 30 in the 90degf column of table 310.16. however there is a foot note that limits 12ga to 20a only. in oem builds, they can use this higher rating as long as UL or whomever they use for their acceptance testing signs off on it. we in the field cannot use 12ga for 30a because of the code limitations. I would not bother changing any of the factory wiring but I would use 10ga for any wiring you add.

 

[diovol]

this is a tricky one that trips up many people. the rating on 12ga thhn insulated wire which is the most commonly used wire is actually 30 in the 90degf column of table 310.16. however there is a foot note that limits 12ga to 20a only. in oem builds, they can use this higher rating as long as UL or whomever they use for their acceptance testing signs off on it. we in the field cannot use 12ga for 30a because of the code limitations. I would not bother changing any of the factory wiring but I would use 10ga for any wiring you add.

exactly what i am doing.... thank you.