UPS for Air Conditioners and Motors
Q: Can I use a UPS for an air conditioner or motor supply?
A: No — these are very harsh loads that distort mains supply due to high inrush currents on start-up, and often regenerate power back into the supply on switch-off (a “regen load”). The high start-up currents typically exceed what the UPS inverter can deliver — the inverter has a peak-load capability but only for very limited duration.
Two workarounds:
- Place a variable-speed drive (VFD) between the UPS and the motor, which soft-starts the motor and protects the inverter
- Use a generator instead of a UPS for these load types
Loads to watch for in the same family include: laser printers, pumps, large LED lighting (leading power factor), blade servers, and any motor-driven equipment.
Connections
- FAQ - Loads That Cause Problems — relates, source: https://standbysystems.co.za/ups-batteries-questions-and-answers/