IS 325 is the primary specification for three-phase induction motors (the most common motor type) in India. It covers standard ratings from 0.18 to 315 kW, efficiency requirements, starting characteristics, temperature rise limits, and testing procedures. Referenced in pump, fan, and compressor specifications across all sectors.
Specification for three phase squirrel cage induction motors covering ratings, performance characteristics, testing, and marking for general purpose industrial use.
Key Values
Voltage415V ±10%, 3-phase, 50 Hz
Insulation classF (155°C) standard, H (180°C) option
IP protectionIP55 (standard enclosed)
Practical Notes
! Always specify IE (International Efficiency) class: IE2 is the BIS minimum, IE3 is recommended for energy savings.
! Standard voltage in India is 415V 3-phase. Motors designed for 440V or 460V (US) will run differently on 415V.
! For pumps and fans, check motor frame size compatibility with the driven equipment before procurement.
! IS 325 motors have higher starting current (6-8x rated) — check DOL starter capacity or use star-delta starter for >7.5 kW.