Nederman Electrical Serie Manuel De L'utilisateur page 26

Do not touch the motor with any tool during this operation.
Motors
Thermal function
Unplug the power cable before removing the covers.
Cable connections and
screws
Carbon brushes
Commutator
Motor
26
Check that the motors are running
clockwise as seen from above.
Control the thermal function by
blocking the cooling air inlets with
sheets of paper. The motors should
be switched off by the thermal func-
tion when the temperature exceeds
approximately 75°C/167°F.
Loose cable connections and
screws.
Worn-out carbon brushes.
Contaminated commutator
Resistance in the bearings.
See Chapter 7 Troubleshooting.
Secure cable connections, and tighten
screws.
Replace.
Brushes shall be replaced after
900 hours of use. See
Clean the commutator.
Replace the motor.
Figure 13 A.