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Operation and maintenance manual for
Hydrotech Drumfilter HDF501-series
5.2.1.HAND.mode.–.continuous.rotation
During continuous drum rotation and backwash, the water level inside the
drum is kept nearly constant.
The level sensor and the automatic control system are disabled when HAND
mode is selected.
5.2.2.AUTO.mode.–.automatic.level.control
With level control, the drum rotation and the backwash pump is activated when
the water level inside the drum reaches the level sensor. If an independent
rinse water supply is used, the level sensor controls a solenoid valve instead
of the pump.
The water level inside the centre drum will vary when AUTO mode is selected.
The lowest level is just after a backwash cycle, and rises until the level sensor
is reached. If a constant water level inside the drum is required, the filter
should run continuously (HAND mode).
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