Hope this is an ok area for the ?. Cust. has a Powermatic 3520b lathe and all I can find is that it's 3 or single phase, 2hp. Someone (co. ?) told him it takes a 40a breaker. Does this seem excessive? Resi basement location.

Look on the motor nameplate and get the FLA
(full load amps). If its single phase the FLA should be about 12 amps. Use a 25 or 30 amp breaker. If its 3 phase the FLA should
be about 7 amps. 15 or 20 amps breaker. usually a residence does not have 3 phase service. You may have to change the motor.

Don't be too quick to jump to the conclusion that it's a 230 volt wired motor.
A 2hp motor will draw about 24 amps when wired for 115.
If that were the case, a 40A Breaker wouldn't be excessive

If it a 3 phase motor, you can use a small VFD to generate the 3 phase from a single phase input.

Larry

Thanks guys. It's an either/or unit. I don't carry 8-2 in the van and was hoping against another trip for wire. Electure, is that run or start? Does that apply?

Here is the link with the manual for the lathe. It seems wierd that in the specs it doesn't list the FLC. It does state that it is a 230v motor like you said single/or three phase.

http://www.wmhtoolgroup.com/shop/index.cfm?navPage=4&iid=6056397

Go to page 13 of the manual, it already has a inverter.

Viewed the .PDF manual, available from the link that RobbieD provided.

Found out the following about this Lathe:

<OL TYPE=1>

[*] The Lathe Motor is powered and controlled via an intregal VFD, which is Factory installed,


[*] The Motor is a TEFC make, rated for 2 HP at 220V, 60 Hz,


[*] No indication if the 2 HP Motor is Single Phase or Polyphase - but seeing that the Motor is controlled by a VFD, I am thinking it would be a Polyphase Motor - likely a Wye connected TEFC type 3 Phase Squirrel Cage Induction Motor,


[*] The machine may be connected to either a 1 Phase 230 Volt power system, or a 3 Phase 230 Volt system,


[*] If 1 Phase 230 Volt, 2 Wire system is used, the Factory's Standard 3 wire cord, supplied with the machine, may be used and no alterations need to be made to the machine,


[*] If 3 Phase 230 Volt 3 Wire system is used, the cord needs to be changed out with a 12/4 cord, and termination alterations are required.
</OL>

No FLA ratings are listed anywhere, so it seems like the Branch Circuit might be best rated for the FLA of a 2 HP 230 Volt 1 Phase Squirrel Cage Induction Motor.

As viewed by the NEC, this would result in at least 12 FLA for a 230 Volt Motor, and at least 13.2 FLA for a 208 Volt Motor.

Looks like a 20 Amp Circuit would be sufficient for the Lathe, and a Breaker from 20 Amps to 40 Amps could be used.

Definitely need to do these two things first:

1: Check the nameplate's ratings, and base circuitry ratings from that,
&
2: RTFM!!!
(stands for: Read The Fu..,, err... Fine Manual)

Scott35

Thanks all- I finally got to see the lathe; nameplate read 17.5a @ 240v 1ph.Used 10-2 for the circuit,20a bkr. Why 'they' told the h/o 40a is beyond me.