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Operation & maintenance manual, Drum filter HDF 12/16/20/24 -series
8.6 Drive chain, drive with chain type H78
Drives with chain type H78 have plastic chain wheels; Figure 8.11 shows chain type H78 and chain
wheels. The filter is powered by a worm gear motor and a chain. See Appendix A and F for tech-
nical data.
8.6.1 Checking the drive chain for wear
The drive chain must be checked per the maintenance chart (see section 8.9). Start operation
again as in section 6.1 (Check measures for restart).
Before beginning maintenance or service, ensure that the main power switch is locked in
the OFF (0) position with a padlock.
8.6.2 Checking drive chain tension
Wear to the centre shaft’s bearings or to the drive chain affects the chain tension. Check the drive
chain tension as follows:
1. Stop the filter (turn the main power switch to the OFF (0)
position and lock it in the OFF (0) position with a padlock).
2. Tension the chain by turning the drum by hand in either
direction.
3. On the chain’s non-tensioned section, use a steel rule to
check that deflection is 25–50 mm: see Figure 8.11.
4. Adjust the drive chain tension as necessary according to
section 8.6.3 Adjusting drive chain tension.
5. Start operation again as set out in section 6.1. Check the
chain tension per the maintenance chart (see section 8.9).
Figure 8.11 Checking drive chain tension
