26 Oct 2022

Bespoke Pit Fan Motors With Fin Cooling

MENZEL ELEKTROMOTOREN HAS designed and manufactured three powerful 6,600V squirrel cage motors as integral components for pit fans. A customer specified cylindrical motor casings as compact as possible. The greatest challenge was implementing the required rated power of 1,700kW in cylindrical casings. To achieve this, Menzel designed fin-cooled motors (cooling type IC 411) in frame size 630, an unusual design for motors this large.

The manufacture is complex, but the result is optimal for the constricted installation conditions. To save additional space, all connection cables are routed out of the motors, and the terminal boxes are mounted outside the fans.

Since the driven fan wheels are mounted directly on the motor shafts, the motor bearing must compensate for additional high loads; radial loads up to 20700N and axial loads up to 27000N.

For the required bearing service life of 100,000 hours, Menzel implemented a special rolling bearing setup. In addition, the motors have a second shaft end for a holding brake. The three-phase squirrel cage motors are designed for operation on a frequency converter (duty type S9) with speed changes and reversal of the rotation direction. This allows the pit fans to ventilate the mine and extract dangerous firedamp if necessary.

 

www.menzel-motors.com