This ones for all you industrial electrical guys. Question is how much of a phase unbalance do you guys see in older factories. when plants are set up they are balance fairly well but over time the system can become unbalanced by the adding of single phase circuits. how much is exceptable and how will this effect motors on machines and other equipment. i took some readings from the main panel that feeds our overhead buss bar and this is what i came up with after the figures
it came to 4% unbalance which is equivalent to a 32% raise in temp for motors,
i also took a reading on a motor on one of our machine tools and came up with a 3% unbalance or 18% increase to motor temp.
so how much is exceptable and how can you correct for years of adding single phase circuits with out taking phase unbalance into consideration.
