LSPM motor
Compressors equipped with an line start permanent magnet motor (LSPM motor) can be identified by the letter "U" added to the model designation (e. g. GSU60120VLB4-2). The built-in permanent magnets generate a non-negligible magnetic field which, however, is shielded by the compressor housing.
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Safety signs attached to the compressor
![](../assets/img/SmallWarningYellow.gif)
![](../assets/img/SmallWarningYellow.gif)
Strong magnetic field!
Keep magnetic and magnetizable objects away from compressor!
Persons with cardiac pacemakers, implanted heart defibrillators or metallic implants: maintain a clearance of at least 30 cm!
Work on a compressor with LSPM motor
Any work on the compressor may only be performed by persons that are not part of the specified group. Maintenance work beyond the work described in the present document and in the Operating Instructions ESB-130 may only be performed after consultation with BITZER.
![](../assets/img/SmallWarningYellow.gif)
![](../assets/img/SmallWarningYellow.gif)
Induction, electric voltage!
Never operate the motor with the terminal box open!
When the rotor rotates, electric voltage is induced in the terminal pins – even with the motor switched off.
The PTC temperature sensor integrated in the stator as a standard protects the LSPM motor from overload when the temperature rises (e. g. in case of prolonged locked rotor conditions). It is recommended installing an additional overload protective device that reacts more quickly, since repeated locking conditions would damage the magnets.
Permitted work on a compressor with LSPM motor
Work on the electric supply and screwed connections in the terminal box, oil change as well as inspection and replacement of pressure relief valves, cylinder banks and sight glass. No special tools are needed for this work. Before opening the compressor, thoroughly clean its environment. Pay special attention to loose metal particles! Do not open the motor cover!