Auto paint booth

[papa]

I got called to wire a auto paint booth that has been relocated, to a new building that does not have a three phase service. It was originaly three phase. The owner has replaced the two 1 1/2 hp 3 phase exhaust fan motors with 1 1/2 hp single phase 240 volt motors . there may also be a third motor the same size installed later. Also there is two 120 volt lighting circuits total of 14 amps , and a solinod to kill the air line in case of a fire. The fire ex. system has a micro swith that is s/p d/t that is tripped in case of fire to shut down tht fans and air. The motors are started with two manual starters which I dropped one conductor on and resized heaters for new motors. My question can I install one 50 amp shut tripp breaker and pull # 8 thhn to a power block , then # 12 to fuse blocks for each motor starter? The lights will be on two seperate 20 amp circuits.

 

[bob]

My question can I install one 50 amp shut tripp breaker and pull # 8 thhn to a power block , then # 12 to fuse blocks for each motor starter?

1. According to table 430,248 a 1.5 hp motor draws 10 amps. Using a 50 amp breaker would violate 450.52. Are you saying that you would fuse the #12
per 450.52?

3. You need to determine if the paint booth will be classified under Section 500.

 

[benaround]

papa, I'd say your ok as long as tap is under 10' to fuses.

note: The new motors are explosion proof, right ?

 

[papa]

The #12 taps to fuse blocks will be less than 10 ft. The fan motors are mounted ouside the paint booth, so they do not have to be exlposion proof . Thanks, Eddie