Prebena MOUNTAINE 950, Manual

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PREBENA
Wilfried Bornemann GmbH & Co. KG
BEFESTIGUNGSTECHNIK
– FASTENING TECHNOLOGY
15
Table 2
Thread
Minimum
tightening torque
Maximum
tightening torque
М6
9 Nm 11 Nm
М8
22 Nm 27 Nm
М10
45 Nm 55 Nm
М12
76 Nm 93 Nm
8.2.6 Checking the belt tension (belt-driven compressors only)
Check the belt tension after the first 50 operating hours and then every 300 hours. If
necessary, adjust the voltage and clean the belt. If the voltage is too low the belt slips,
thereby causing vibrations. This, in turn, causes damage to the bearing due to the
changing load transfer. The pulleys overheat and the power coefficient of the piston
cylinder decreases. If the belts are too tight, the bearings are overloaded and the wear
increases, overheating the electric motor and the piston cylinder.
Check the belt tension as follows:
1 Switch off the compressor in accordance with Point 6.7.
2 Remove the protective device.
3 Apply Force F with 30 - 40 N perpendicular to belt centre (Figure 4).
4 Measure movement X (Figure 4). Belt deflection X should be 5- 6 mm.
5 If necessary, adjust the belt tension. After loosening the screws that hold the
motor to the base plate, adjust the tension by moving the electric motor. Ensure
that the electric motor and the pulleys of the piston cylinder are on the same
plane.
6 Secure the motor and mount the protection device.
Figure 4