I just came across a job were the services needed to be relocated to make room for a bridge.Anyway the power co. wants to change the services from a delta 240 to a wye 208. Should i concern myself with changing the heaters? Thanks.
I am sorry, I am talking about the overload heaters in starters. I know there is a 15 to 20% window on the voltage, but not sure on the load. I know 208 is more efficient so the amperage will be less, and with heaters being a little more precise on the motor load and just another means of protection. Usually when i order starters they specifically ask the fla. with the 125%. And for SC. poco they typiclly use phase c. blue for the high leg. I guess to be different. Anyway I am new to this forum, and will be asking more than answering. With this forum there is really no need for continuing education.
What is the nameplate voltage of the motors? There is only a 10% window on the motors. In order to provide X amount of HP, the voltage/current relationship will be inversely proportional. If the motors are listed as 240 volt, you should not operate them at 208. However, if you do, the current will probably increase and if your OL protection is properly sized, the relay will likely trip.
[This message has been edited by Redsy (edited 07-15-2002).]
The statement that 208 is more efficient is misleading, if not incorrect. A motor running on 240 will pull more amps when connected to 208. The amps will drop when going from 240 to 208 on resistance loads, i.e. electric heat.