230-Volt Motors on 208-Volt Service
Will slightly under-powering 3-phase shop equipment cause trouble? Probably not, but there are ways to modify voltage just in case. November 21, 2005
Question
I'm looking at a machine that is rated for 3 phase 230 volts, but my shop is wired for 3 phase 208 volts. Will the machine run or will it run poorly?
Forum Responses
(Cabinetmaking Forum)
From contributor R:
We have 208 three phase in our shop and a mix of machines with motors rated for 230 and 208 with no problems. Contact your local motor repair folks for a more detailed explanation, but I recall that it may not have full power. However, we can't notice any measurable difference.
From contributor L:
Operating a motor rated at 230 vac on 208 vac will cause the motor to operate at a higher temperature and slightly less HP will be produced. Motors are usually rated to run at +-10% voltage, so this falls within the guidelines, barely. If you want to do the proper thing, get yourself a pair of buck/boost transformers to boost your voltage to 230. They will cost you about $110 apiece and when you get them, make sure you ask the seller to send you the literature on how to wire them up for your 3 PH power. You can always find wiring diagrams on the net. Good luck, and be safe when playing with power.
From contributor B:
I have the same situation and had the same concerns. No problems for two years running. I think you'll fall within the percentage.
From contributor J:
Most of the time you will not have any problem running a 230 motor on 208. Do keep in mind that during the summer months, our voltage sometimes drops down to 194-198 volts, which is well more than the +/- 10%. If you have more than one machine that is rated at 230, consider installing a larger dedicated transformer and panel board to run those machines at 240 delta. You need a 240 volt primary by 208Y/120 secondary transformer. You'll be using this in step-up configuration, so do not hook up the neutral wire. A 30 KVA transformer will give you 72 amps at 240. If you can afford to wait a little while, you can find everything you'll need on E-bay for probably just a few hundred dollars.
