WARNING
Beware of rotating pulleys and moving belts.
There is danger of serious injury from pinching.
➤ Never check the drive belts unless the engine is at standstill.
➤ Never run the machine without a belt guard.
➤ Open both doors.
10.4.8.1 Visual check
1. Remove the belt guard, if fitted.
2. Check the belts thoroughly for cracks, fraying or stretching.
Replace damaged belts.
10.4.8.2 Checking belt tension
Check belt tension when they are warm, not hot, to avoid length variations through temperature.
The engine manufacturer recommends a tension measuring device for belts. For operation see the
engine service manual.
The belt tension may also be checked by hand if no tension measuring device is available.
Fig. 61 Belt tension checking by hand
A
Permissible deflection of the belt
*
Approximate pressure exerted: 10 kg
Permissible movement: 10 – 15 mm
Checking belt tension with tension measuring de‐
vice.
Belt tension checking by hand
1. Check belt tension with the tension measur‐
ing device.
2. Increase the tension on loose belts.
3. Replace the belt guard.
Press the belts in with the thumb at the mid-point
between pulleys.
1. Check belt tension by hand (see Fig. 61).
2. Increase the tension on loose belts.
3. Replace the belt guard.
10 Maintenance
10.4 Engine
No.: 9_6975 00 E
Service Manual Screw Compressor
M135 SIGMA CONTROL MOBIL
119
