Changing the belt
1. Loosen the locking nut
2
.
2. Turn adjusting nut
1
to loosen the tension on the belt until it can be removed from the pulley.
3. Install the new belt and use the adjusting nut
1
to adjust tension until the marker pin reaches
the lower end of the elongated hole.
4. Tighten the locking nut
2
.
10.10 Testing the safety relief valve
In order to check the safety relief valve, the machine's working pressure is raised above the acti‐
vating pressure of the valve.
Blow off protection and air system pressure monitoring are switched off during the test. In normal
operation, the blow-off protection will switch off the machine before the safety relief valve responds.
During the inspection, the blow-off protection will switch off the machine only when the activating
pressure of the safety relief valve has been exceeded by 14.7 psig.
➤ Follow the detailed description of this procedure in the SIGMA CONTROL 2 operating
manual
➤ Never operate the machine without a correctly functioning safety relief valve.
➤ Have a defective safety relief valve replaced immediately.
Excessive noise is caused when the safety relief valve blows off!
➤ Close all access doors, replace and secure all removable panels.
➤ Wear hearing protection.
Precondition The machine is switched off.
1. Close the user's shut-off valve between the machine and the air distribution network.
2. Read off the activating pressure on the valve.
(the activating pressure is usually to be found at the end of the part identification)
3. Log on to SIGMA CONTROL 2 with access level 2.
4. Observe the display of pressure on SIGMA CONTROL 2 and call up the test function.
5.
Risk of burns due to released cooling oil and compressed air when blowing off
the safety relief valve!
➤ Close all access doors, replace and secure all removable panels.
➤ Wear eye protection.
6. End the test as soon as the safety relief valve blows off or working pressure exceeds the acti‐
vating pressure of the safety relief valve by nearly 14.7 psig.
7. If necessary, vent the machine and replace the defective safety relief valve.
8. Deactivate the test function
9. Open the user's shut-off valve between the machine and the air distribution network.
10 Maintenance
10.10 Testing the safety relief valve
9_5875 33 USE
Operator Manual Screw Compressor
SM Tri-Voltage, SIGMA CONTROL 2
63
