step up transformer

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nizak

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I have a commercial building, the utility service is 200 amp 240V 3phase delta power. The building owner wants to install a piece of equipment that has electrical requirements of 60Amp/480 Volt 3 phase. In speaking with some local electricians I've found it seems "uncommon" for an application such as this where the secondary voltage will be 480 and the primary 240. Is this a common practice to do this? BTW, 480Volt power from the utility is cost prohibitive in the area this is. Thanks anyone for your comments.
 
I would have concerns over capacity. That one piece of equipment is 60% of the service if it is non-continuous. I think it warrents an investigation.
 
Voltages and tripping

Voltages and tripping

The new load is 50kW at 480V. The existing service is rated for 83kW. I think you are going to have problems. The 240-480V transformer, square D makes them, will introduce voltage drop. If you are adding a motor, the starting current could drop voltage significantly and you will have problems. Depending on the sizeof the utility transformer(s), there may not be enough capacity.

Sorry to say, IMHO, I think a service upgrade is needed. If you could go to 480V 200A, then step down for the small existing 240V load, you might be able to serve the added load and hold costs down, somewhat.

Is this new piece of equipment available in a 208V version? That might solve the voltage drop problem but I think you will have problems with supurious(?) tripping of the main breaker because you are so close to the rating.
 
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