Nederman VAC 20, Instruction Manual

Page: 27 / 328

VAC 20
27
EN
8.2 Belt transmission
Perform the following belt transmission inspection every 500 hours of operation:
1. Remove the belt guard.
2. Remove the motor side panel for easy access to the screws that anchor the motor.
3. Replace worn or damaged belts and pulleys.
4. Check the tension of the belt transmission and adjust if required.
The following figures can serve as a guide for all VAC models and give the force F
necessary to apply to one of the belts as shown in Figure 9 for 10 mm slack:
–
New belts: F=24 N (5.4 lbf)
–
Used belts: F=20 N (4.5 lbf)
5. Put back the motor side panel.
6. Put back the belt guard.
NOTE! New belts are liable to stretch slightly within the first 50–100 hours of use and
are to be more tightly tensioned than used belts.
8.3 Anti surge control
Every 500 hours check that the unit does not pump and that the valve ‘floats’ at varying air
flow. See sections 7.2.4 Adjusting Anti Surge Control by PLC or 7.2.5 Adjusting Anti surge
control by optional adaption kit.
8.4 Start-up valve
Perform the following start-up valve inspection every 500 hours of operation:
• Check that the spring holds the valve closed when the unit is standing still.
• Check that the spring holds the valve closed when the motor is in Y-mode.
• Check that the valve is open when the motor is in D-mode.
8.5 Flow restrictor FR 160
Perform the following flow restrictor inspection every 500 hours of operation:
• Check that the flow restrictor is activated when the motor current tends to exceed
the nominal current. Observe the damper arm at varying air flows. The variation must
cover the range where the restrictor is activated. If adjustments are necessary, see
Section
‘8.5.1 Adjusting FR 160’
.