3 Phase motor starter for a 1 phase motor (FNG)

[outlawspeeder]

If this is in the wrong spot please let me know.

I am looking for a hand or rewiring the controls for a 3 phase motor to a one phase motor. I am a home machine shop guy normally but I figure like the forums I use, people like to help each other.

Below is a pic of a CR 106 B1. It was used to start a 3 phase motor and to protect the motor. Is there a way to use this to power a 1 phase motor. I plan on using 220. The power switch is a push button on and off. The old motor is a 3 phase 3/4 hp and the new motor is 1 phase 3/4 hp. Is there a better way?

I can't find a wiring schematic for to use this for 3 phase let a lone 1 phase and the cover panel is missing. The wires inside was removed before I got it. I can play and figure it out but I don't want to let the magic blue smoke out of it.

Yes I know I can use a VFD, phase-o-matic, rotary phase converter.... But I have the motor.

Thanks





https://www.google.com/url?sa=t&rct...0and%201.pdf&usg=AOvVaw33lU7ucXoda6DE4VayoJHA

 

[Bluejets]

Why would you need a starter for a single phase motor of that size?
Just plug in and turn on.

 

[outlawspeeder]

Does the starter (CR 106) provide protection to the motor? Does the motor need protection? It is being used in a medium size band saw.

 

[Minder]

Normally when using a 3ph contactor for a 1ph motor it is normal for the live conductor to be looped out of the bottom of the O/L and through the next contact input, IOW poplate the three entries and exits.
M.

 

[Tha fios agaibh]

I would loop together 3 contacts on top and connect it to line (mains) voltage and then tie motor load to the bottom contacts under the heater elements.

You only need one contact, but since a 1 phase motor will draw more current than the 3 phase motor i would bridge the contacts. You'll probably need to change original heater elements on the starter to a higher current (heat#) to suit your new motor or it will trip the overload relay under a heavy load.

 

[Minder]

This shows how it is done with 240v 1ph if not switching the neutral then another loop is required for L1.
https://springercontrols.com/news/single-phase-motor-3-phase-contactor/
M.

 

[Bluejets]

Still say it's not necessary but if the Op needs control via a control circuit, say for a control isolator such as emergency stop, or a foot switch or whatever, then one would need to know the voltage of the control.
If it is originally derived from the 3 phase i.e. 415v then forget it.
If there was a neutral fed in originally on the 3 phase, then ok.
But then there is the overload unit which may not be within the range as they do vary depending on whether a star or delta wind.
Either way, the single phase would come normally with their own internal thermal overload.
All depends on many aspects of the actual motor.