Machine Xfmr question?

[milmat1]

Folks,
I am designing a control system for an industrial machine. Machine is 480VAC / 3PH powered.
And I have a 480 / 120V transformer for control voltage etc. (Transformer can be wired for 240 or 120 on secondary)

Now we have added a 230VAC servo drive. Is it considered OK to use this transformer for both my 240V , and the 120V control voltage?

If so, should I tap the winding at 120V and use the 240V winding?

Or do I need to add a 2nd transformer just for this 230V servo.

 

[LarryFine]

Now we have added a 230VAC servo drive. Is it considered OK to use this transformer for both my 240V , and the 120V control voltage?

If so, should I tap the winding at 120V and use the 240V winding?

Or do I need to add a 2nd transformer just for this 230V servo.

As long as you have the ampacity, I cannot think of a reason it shouldn't be done.

You will want to bond the center tap as a neutral to the building electrode system.

 

[petersonra]

I think I would be inclined to just add another transformer, unless the transformer you already have is big enough to handle the new load. But it's a design decision and up to the engineer designing it. Personally I'm not sure it matters one way or the other.

 

[milmat1]

I think I would be inclined to just add another transformer, unless the transformer you already have is big enough to handle the new load. But it's a design decision and up to the engineer designing it. Personally I'm not sure it matters one way or the other.

I am inclined to do this, as the transformer sizing would be marginal to use what I have already ordered.

Thank You All

 

[herding_cats]

I need the VA rating of the transformer, and the load requirements of the servo and I can calculate this all out.

 

[Jraef]

My only concern would be that a problem with the servo blows the fuses on the transformer, then you lose all controls, including the ability to annunciate the servo failure. So some poor electrician has nothing to work from to figure out what’s wrong, possibly increasing down time. 10 extra minutes of down time might more than exceed the cost of a separate transformer.