2 motors the same

[jim123]

I'm in the process of changing from two single phase 208 motors 2 hp ( 20.5 amps each) to a new system of two 3 phase 208 motor 2hp (5.5 amp).There are two 30 amp feeds coming from a panel for these single phase motors, what I want to do is to use the wires to feed the two 3 phase motors only using one 30 amp 3 phase breaker (inverse} and wire is thhn all in emt. Would I have a problem with inrush and would I have to now put a disconnect close to these motors. These 2 motors are on a controller for sump pumps . They will be alternating but there is a possibility that both could run at the same time.Thanks for your help

 

[Cow]

What about overload protection? What will control them?

 

[jim123]

the control cabinet has two motor starters with overloads and there is a separate 120 feed for the control which operates the float switches

 

[GoldDigger]

To be used for a new three phase circuit, the existing wires must all be in the same raceway. Are they?

 

[jim123]

yes all wires are coming from the same panel

 

[ActionDave]

Sounds good to me.

 

[kwired]

yes all wires are coming from the same panel

But are the conductors of the circuit between the panel and controller or any other enclosures all in same raceway or cable? That was the bigger question. If you had a conduit for each motor before you can not use two conductors in one raceway and the third in another raceway.

 

[jim123]

But are the conductors of the circuit between the panel and controller or any other enclosures all in same raceway or cable? That was the bigger question. If you had a conduit for each motor before you can not use two conductors in one raceway and the third in another raceway.

Yes all conductors r in the same conduit

 

[GoldDigger]

Yes all conductors r in the same conduit

That part would be OK then, just mark the one black conductor that is now on a different phase.
The remaining concern will be to follow the NEC rules for multiple motors on one branch circuit (in terms of wire size, OCPD (overload and short circuit) and disconnects), and those are fairly clear.

 

[tom baker]

430.102 requires a disconnect within sight of the motor and controller, there is an exception for submersible motors.
Disconnects must be capable of being locked in the open position.

 

[GoldDigger]

... there is an exception for submersible motors.

For a sump pump, I guess without the exception "in sight" of the motor would depend on the clarity of the water in the sump.