Largest 120V Motor

[Npstewart]

Doing a project with a bunch of pool/fountain equipment. The equipment supplier gave us a list of equipment with the voltage and KW of the motors. some of these motors are requiring about 50amps @ 120V. Which means I would need a 60A/1p breaker. My question is, did someone put together this list that didn't know what they were doing?

The largest 120V motor ive seen is about 30A. Is it possible to even get a 60/1p breaker? Im thinking that these motors should be running off of 208. If they were running of 120V would they be very expensive to build?

As always, thanks.

 

[cpal]

without regard to operating voltage in general an inverse trip bkr for a motor branch circuit IAW Table 430.52 may be set @ not more than 250% of the motors FLC.

A 50 Amp motor may well need a 125A Inverse Trip Breaker.

 

[iwire]

I agree with cpal, I doubt a 60 would hold the start up of a 50 amp motor.

You do not have to use a single pole breaker, you can use one pole of a two pole if you have to.

That said, yeah it seems odd to use 120 volt motors that large.

 

[sii]

A quick search of Baldor's website shows that a 3hp motor, which is the largest single phase I could find, is rated at 25 FLA at 120 volts. The 50 amps mentioned would suggest somewhere well over 5 hp. I'm not sure you could find a 120 volt motor that large....I've never seen one anyway. Why not just use higher voltage motors?