Interroll Drum motor series i, S, S/A, D
Troubleshooting
98
Version 4.1 (06/2015) en-US 
Translation of original instruction manual
Fault Possible cause Remedy
Motor heats up in regular 
operation
Overload of the drum motor Check rated current for overload.
Ensure that the motor is not rubbing against the conveyor belt 
frame.
Ambient temperature above 
40 °C
Check ambient temperature. If the ambient temperature is too 
high, install a cooling unit. Contact local Interroll dealer.
Excessive or frequent stops/
starts
Check whether the number of stops/starts corresponds to the 
specifications of the drum motor and reduce this number if 
necessary. Install a frequency inverter to optimize the motor 
output.
Do not use motors of the S-series for start-stop operation.
For motors of the i-series, the start-and-stop ramps may not be 
less than 0.5 seconds. Ramps can be set with a frequency 
inverter. For shorter ramps, a motor of the D-series must be 
used.
Contact local Interroll dealer.
Belt tension too high Check belt tension and reduce as necessary.
Motor is not suitable for the 
application
Check whether the application meets the specifications of the 
drum motor.
Use special reduced-power motors for the operation with link 
belts or without belts.
Coating too thick Replace coating or contact local Interroll dealer.
Wrong voltage supply Check the voltage supply.
For single-phase motors, ensure that the correct starting or run 
capacitors are used.
For 3-phase motors, ensure that no phase has failed.
Wrong settings at frequency 
inverter
Check whether the frequency inverter settings meet the 
specifications of the drum motor and change them if necessary.
Loud noise of drum motor in 
regular operation
Wrong settings at frequency 
inverter
Check whether the frequency inverter settings meet the 
specifications of the drum motor and change them if necessary.
Loose motor mount Check motor mount, shaft tolerances and fasteners.
Belt tension too high Check belt tension and reduce as necessary.
Wrong/incorrect profile 
between drum shell and belt
Ensure that belt and drum profile match and are correctly 
connected. Replace as needed.
Observe installation guidelines of the belt manufacturer.
Drum motor incorrectly 
mounted
Check the mounting location of the serial number (See 
"
Positioning the drum motor", page 76).
An outer conductor failed Check connection, check supply system.