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	Subject - Can I run older 240V 3 phase motors on 208V? hobbie5o I have a shop full of older machines with 240 volt 3 phase motors. I just moved into a newer building with 208 volt 3 phase service. Can I ru these older motors on the lower voltage without damaging them? We typically do not run the machines anywhere near full load. JimmyDee I wouldn't run full load but you will have no problem running at 208 volts. Even though the older motors aren't rated for 208, I've found no problem in running them at 208. I would leave the 240 volt heaters in the starters so if the amperage is increased because of the lower voltage, they will trip out before damaging the motor. Jim hobbie5o Some of the machines have 230V and 220V (all 3 phase) listed on their motor plates. Are these better suited for the 208V without damage? These are older machines (~1950-1970), did they design for 240V with line losses, or did they actually run 220 and 230 volts? By the way, thank you for your previous reply. We have the machines up and running. Thanks, Scott. JimmyDee I really think the voltage is nominal and isn't that critical. When I was an apprentice everything was 110/220/440 and it is the same voltage as the 120/240/480 is today. I think it is the manufacturers choice and doesn't really mean anything. Jim skynrd The reason for the 240v is back when the power companies and electrical equipment manufactures all used a delta configuration on their 3 phase equipment when they started using the wye configuration the squre root of 3 IE: 1.73 (remember this # you'll need it)factors into all your 3 phase electrical calculations. Lenny PS God I'm getting old.