Help,
I'm a residential electrician and don't work much with 3 phase power. My question is on a 3 phase 480 volt system is it abnormal to read 490 volts? I have a ac unit rated for 460 volts (nominal voltage) however as stated we are reading 490 volts at the unit. Is this a reason to be concerned? I should mention there are 3 other units on the roof also rated 460 volts and are operating normal.
Any feedback would be greatly appreciated.....
