21
Operation and maintenance, Discfilter HPF2200-series PFLC
5.2.1 Level differences
The maximum permitted difference between
the water levels inside and outside the drum
is 250 mm during normal operation (see Figure
5.4). The recommended level difference is 100–
200 mm.
If an even flow after the filter is required, the
filter must be run with a small level difference.
The filter must be installed so that the
level difference in the event of operating
disturbances under no circumstances ex-
ceeds 450 mm.
The filter must be run so that the level difference during normal operation does not exceed
250 mm.
Prolonged operation with a greater level difference will significantly shorten the life of the
filter panels and other vital parts.
5.2.2 Operating mode AUTO – Automatic level control
With automatic level control, drum rotation and the backwash pump are activated once the le-
vel difference between filtered and unfiltered water exceeds an adjustable value. The filter is
force-started if the filter has stood still for an extended period of time. If an external backwash
water supply is used, the level sensor can control a solenoid valve instead of a pump.
The water level inside the drum will vary when AUTO mode has been selected. The water level
is at its lowest immediately after a backwash cycle and then rises until drum rotation and back-
washing start.
5.2.3 Operating mode REMOTE – Remote control
In REMOTE operating mode, the filter can be controlled remotely. In remote control mode, the
filter can either be controlled as if in AUTO operating mode or using an external controller, see
the “Automatic System Manual”.
Figure 5.4 Maximum permitted level difference during
operation.
