Control Transformer Question?

[NCIVAN]

I have a project using 480 to 120 vac control transformer. I also need to run one small 1.5 amp 120 vac motor. Has anyone upsized and used the control transformer to do this?

 

[mbartoli]

While you don't provide much detail in your description of the system, Good practice would be to use a separate transformer for motor loads to avoid motor operation influencing the control system.

just my .02

 

[NCIVAN]

Thanks for your .02 I do appreciate it. I am working to find out if I will even need to run this small motor when the other 6, 480vac Motors run. This small motor may only run during Change Over for positioning.

 

[MasterBlaster]

If you elect to use one transformer, over-size it and fuse the motor separate from the control circuits. FAR better to use two transformers.

 

[WTFSUNELECSUP]

Code wise, the transformer size has to be 125% for the motor FLA, plus whatever for the controls load, I'd use (2) seperate transformers as the motor will make your power supply dirty. If you still want to use one transformer, use a 480v to 120/230v secondary and place the motor on one leg and the controls on the other, fuse your loads on the secondary side in addition to the primary 480volts side, ground your neutral point and you can always use a surge suppressor if your controls leg if they are electronic,

 

[keithkyll]

Motor "affecting control system", "make your power supply dirty", etc. Where do you guys get this stuff?
The electric company uses one transformer to power your house, and possibly some neighbors.
NCIVAN, upsize, fuse properly, and relax. It will work fine.
Make sure one side of the output is grounded for safety.

 

[NCIVAN]

Thank You

Thanks to all for the responses. This site is awesome!