Adjusting Fr 160; Flow Restrictor Oil; Fan Bearings Temperature; Fan Bearings - Nederman VAC 20 Instruction Manual

EN VAC 20
8.5.1

Adjusting FR 160

Perform the following to adjust the FR160, see Figure 4:
1. Remove the protection cap, Item 5, covering the spring.
For fine adjustments: Loosen the screws, Item 7, to release the disc, Item 8.
For coarse adjustments: Move the free end of the spring to the nearest hole on the
disc.
2. Measure the motor amperage to check the result adjustment. This is usually made
with a clamp ampere meter around one of the three incoming phases to the motor
start and control unit.
A correct adjustment limits the motor current to a reading matching the nominal
current stated on the machine tag. A certain over current, ~10%, is accepted just
before the restrictor goes into operation.
3. Lock the disc.
4. Refit the protection cap covering the spring.
8.5.2

Flow restrictor oil

There is a risk that the restrictor starts self oscillating when the oil level is low. This can
cause damage to the restrictor and the fan.
Perform the following flow restrictor oil level check every 500 hours of operation:
• Turn the restrictor shaft rapidly by hand all the way to the outer end position when
the vacuum unit stand still, see Figure 11.
8.6

Fan bearings temperature

Perform the following fan bearings temperature control inspection every 500 hours of
operation:
• Check the bearing temperature on the two fan bearings, see Figure 1. Normal
temperature range is 50–90 °C (122–194 °F).
If the temperature is above 95 °C (203 °F) ensure the following:
8.7

Fan bearings

Change the fan bearings within 15,000 hours of operation, or sooner if there is reason to
suspect damaged bearings. See mounting instruction MI12-002 for more information.
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– Turn the disc clockwise to increase the air flow and motor load.
– Turn the disc anti-clockwise to decrease the air flow and motor load.
–
If the resistance is uneven: Check the oil level with a suitable probe. Top up
the oil to a level 70-80 mm over the piston surface if necessary. Use automatic
transmission fluid.
– If the resistance is even: The oil level is correct.
– The ambient air is cool. See Section '5.2.1 Location' for information.
– The openings for cooling and ventilation are free. See '5.2.1 Location' for
information.
– The belt is properly fitted. See Section '8.2 Belt transmission' for information
about maintenance of belts.
– The bearings are in good condition. See Section '8.8 Motor bearings' on how to
replace damaged or worn bearings.