Motors: The Proactive Approach To Voltage Unbalance – EASA article

EASAIt’s impossible to balance line-to-line voltages perfectly in three-phase circuits, so they typically differ by a few volts or more. However, if voltage unbalance exceeds 1%, it can markedly decrease the performance and energy efficiency of three-phase motors while increasing the likelihood of premature failure. Avoiding these issues requires a proactive approach that includes installing adequate protective devices and periodically checking for voltage unbalance at the motor terminals.

The article covers:
◾What it is
◾Common causes
◾Effects of unbalanced voltage
◾Testing for unbalanced voltages and single-phasing
◾Ways to correct unbalanced voltages

Read the full article at:

Publication: Engineered Systems
Publication date: June 2016
Author: Tom Bishop, P.E., EASA Senior Technical Support Specialist

Should you have any questions around voltage balancing or require any motor repair or maintenance to be carried out contact Mark Convery on or (0)7713 197130.