According to EU Regulation (EC) No. 640/2009, the IE3 efficiency requirement for low-voltage
motors with a power of 7.5 kW to 375 kW for line operation has been in force since January
From January 1, 2017, the IE3 efficiency requirement for motors with a power of 0.75 kW to
375 kW applies for line operation.
Efficiency IE2 still applies for motors that are operated from a converter.
Please note the applicable country-specific rules and regulations.
The rotor assembly is pressed onto the shaft together with the cage winding. The drive end of
the shaft usually has a cylindrical shaft end. Dependent on the design, a second shaft end
may be located at the non-drive end.
The cooling system is designed as a closed, internal cooling circuit. The heat lost from the
machine is dissipated to the ambient air via the machine's surface. A shaft-mounted fan moves
the cooling air in the primary circuit. Movement of the cooling air in the secondary circuit is
driven by a shaft-mounted fan.
● The internal fans are bidirectional.
● External fan:
SIMOTICS TN Series N-compact 1LA8
Operating Instructions 05/2016
– Machines with four poles and more as well as 1L.831.‑2: The external fans are
– Two-pole machines except 1L.831.‑2: The external fans are unidirectional. The
machines have an additional label on the end shield and on the rating plate with an
arrow indicating the direction of rotation.
The 1L.831.‑2 can optionally also be equipped with a unidirectional external fan.