CB for motor

[elec_eng]

480V, 3ph 3/4hp motor, 1.6 FLA..

Per table 430.52, cb cannot be more than 250% of the FLA, which is 4A..

Minimum cb size I can get is 15A..Is this code violation?

Thanks,

Jey.

 

[ultramegabob]

Use a motor starter with overloads to get the protection you need.

 

[Cold Fusion]

480V, 3ph 3/4hp motor, 1.6 FLA..

Per table 430.52, cb cannot be more than 250% of the FLA, which is 4A..

Minimum cb size I can get is 15A..Is this code violation?

Thanks,

Jey.

Jey -
Read all of 430.52. In particular, look at 430.52.C.1, Exception 1. That lets you go to the next size up cb, which in your case is going to be 15A.

cf

 

[Pham Van Hung]

480V, 3ph 3/4hp motor, 1.6 FLA..

Minimum cb size I can get is 15A..Is this code violation?

Thanks,

hello Jey,
I agree with Cold Fushion, but please also pay attention to the minimum conductor size of 14AWG. Also check conductor rating > CB rating > continous load rating. If you choose too small conductor size, the conductor under certain circumstances can melt before the 15A CB can trip.

Regards,
HUngPV