Nederman VAC 12/20 Manual De Instrucciones página 30

EN VAC 12/20
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.
9.5.2 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 14.
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9.6 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 12.
Normal temperature range is 50–90 °C (122–194 °F).
If the temperature is above 95 °C (203 °F) ensure the following:
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9.7 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.
9.8 Motor bearings
The recommended intervals for replacing permanent bearings or re-greasing
the grease nipple can be found on the motor data label or motor manual.
The operating time before service depends on size, environmental and
operating conditions. As following values are guidelines at normal operation:
• Replace permanent bearings before 15,000 hours of operation.
• Re-grease the bearings at least every 4,000 hours of operation.
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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 '6.2.1 Location' for information.
The openings for cooling and ventilation are free. See '6.2.1 Location'
for information.
The belt is properly fitted. See Section '9.2 Belt transmission' for
information about maintenance of belts.
The bearings are in good condition. See Section '9.8 Motor bearings'
on how to replace damaged or worn bearings.