Interroll Drum motor series i, S, S/A, D
Assembly and installation
Version 4.1 (06/2015) en-US 
Translation of original instruction manual
83
Drum coating
A drum coating (e.g. rubber coating) that was applied retroactively can cause the drum motor to 
overheat. For some drum motors, there may be restrictions concerning the thickness of the drum 
coating.
To avoid a thermal overload, the required output should be multiplied with 1.2.
Please contact Interroll concerning the type and maximum thickness of a drum coating if you 
want to apply one.
Sprockets
To operate link belts with sprockets requires that a sufficient number of sprockets are attached to 
the drum shell in order to support the belt and to correctly transfer the force. Sprockets that 
engage with the belt must have a floating fit to prevent them from interfering with the thermal 
expansion of the belt. Only one sprocket may be affixed for belt guidance; as an alternative, the 
belt may also be guided at the sides.
For a belt guidance with fixed sprocket, the number of sprockets should be odd so that the fixed 
sprocket can be arranged in the center. At least one sprocket should be used for every 100 mm 
belt width. The minimum number of sprockets is 3.
The force is transferred using a key steel welded onto the drum tube. In general, this key steel is 
50 mm shorter than the tube length (SL).
NOTICE
Damage to the belt
4
 Do not use a fixed sprocket together with side guides.