Multiple motors on same branch circuit

[Terry D]

I have (4) 3-phase 208 1/2 hp. fan motors with a FLC of 2.4 amps each that I would like to wire to one branch circuit. Each will have its own starter and disconnect. They will all come on together and go off together by a remote location switch. When sizing the OCPD for this branch circuit, am I'm reading 430.53(A) correctly where it says 15 amps max. If this is correct, I'm thinking it may trip the breaker on start up.

 

[ycgoat]

I read that to say max 20 amps for less than 1 HP motors, but there are other requirements too.

 

[Terry D]

I read that to say max 20 amps for less than 1 HP motors, but there are other requirements too.

I read that 20 amps max is for a 120 volt circuit. These would be 208

 

[larry_g]

Have you considered time delay relays in the start circuit so that you can cascade the start of the fans by a given time delay on three of them?

lg
no neat sig line

 

[ycgoat]

I read that 20 amps max is for a 120 volt circuit. These would be 208

you are correct, I missed that

 

[American Locomotive]

I think you would probably be okay. It's only 2HP total worth of motors. Most breakers won't insta-trip until they hit 7-8x rated current.

I once started a 15Hp motor on a 30a 240v breaker. Start current was 120-140a.

 

[alfredeneuman]

To calculate the feeder load (NEC) take the largest motor and multiply it at 125%
They're all the same size, thus 125% of 2.4=3.
Then calculate the remaining 3 at 100%=7.2
Total is 10.2A