Determine FLC of BLDC Motor

remspot

Member
Location
York, PA
I am trying to determine the FLC of a brushless DC motor for OCPD and branch circuit wire sizes. The motor is from Oriental Motor and is part # BLM6400SHP-GFV which is a 400 watt, 1/2 HP bldc motor. The sticker on the back of the motor shows 2A. I know the NEC has tables (430.XX) to determine the recommended FLC instead of using the nameplates. What kind of motor is this considered, DC? Or do I just go off the sticker amperage, or something else?

We are using a non oriental motor driver that we set the max output current and I have that at 2A. This uses a 120VAC input but has a voltage doubler circuitry (200-240VAC) and converts it to 280-340 VDC bus voltage.
 

tom baker

First Chief Moderator
Staff member
For a motor that small you could use 14 awg and 15 amp ocpd which would be good for short circuit and ground faults. What are you providing for a controller, disconnect and overload?
 

remspot

Member
Location
York, PA
For a motor that small you could use 14 awg and 15 amp ocpd which would be good for short circuit and ground faults. What are you providing for a controller, disconnect and overload?
How did you determine these values? The driver (controller) is described earlier, the disconnect and overload have not been figured out yet since this will possibly have multiple drivers, motors and other current consuming devices for an automation piece of equipment.
 

tom baker

First Chief Moderator
Staff member
I may of misread the motor amps as AC. In the OP you did not mention multiple drivers, motors, etc. So in that case, I don’t know the answer for FLC, and if it’s automation equipment the NEC typically not apply, it could be UL508A or NFPA 79.
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
A BLDC motor typically has to have a drive associated with it, which then falls into the conductor sizing rules for "power conversion" equipment under 430.122; 125% of the INPUT current on the AC side of the drive. The OCPD would be whatever the drive mfr states the drive is listed with.
 
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