I have a customer who bought some used 3 phase industrial mixers. One of the three has a single 2hp motor with a voltage rating of 208 delta/ 360 wye, my available voltage is 240 volt, 3ph. The low voltage amps is 6.6 on this motor. Will my available voltage damage this motor which is continuous duty? Need transformer to step down house voltage? Thanks in advance, Andy
First IMO if you do that you have a code violation.
110.4 Voltages. Throughout this Code, the voltage considered shall be that at which the circuit operates. The voltage rating of electrical equipment shall not be less than the nominal voltage of a circuit to which it is connected.
Along with that it is a bit high, + or - 10% is about as much as you should push it.
208 + 10% = 229.
240 is little more than 15% high.
I would look into getting a pair of small bucking transformers.
Bob Badger Construction & Maintenance Electrician Massachusetts
What frequency is this motor designed for? If it is a European motor designed for operation at 50 Hz, then use at 60Hz will also enter into the voltage calculation, and if the motor runs faster, then this may impact the operation of the mixer.
All other things being equal, a motor designed for 50 Hz operation will require 6/5 the supply voltage and run at 6/5 the speed on a 60 Hz supply.
running a 208 motor on 240 will burn up in time, I know 3 phase motors are exspensive, but is it worth it to buck the voltage down to 208??? well your there to install and make money, but I would think it be better money spent to get a 240v motor beings it only one motor out of the batch he got a deal on.
Thanks for the replies. It's certainly not a new motor, so I'm going check the availabilty of a replacement motor rated at the 240 voltage. The nameplate isn't easy to read due to abuse and painting, but I'll check the frequency rating. Besides, it apparently came from the same place as the 240 volt units and was probably fed with 230 or 240 volts there and is ready to die any day. Andy