When the equipment is operated with a variable fan speed control device, steps must be taken to avoid both
operating at or near to the fan's «critical speed» and below a minimum of 15 Hz for a belt driven unit (or direct
driven fans) or 20 Hz for a unit with gear box. For more information consult your local BAC Balticare
representative.
When operating with VFD drives above nominal frequency be aware of the potential risk for motor overload
or mechanical damages.
It is recommended to provide sinus filters on the VFD to prevent bearing damage on fan motors.
CAUTION
Refer to fan motor nameplate data when programming a VFD.
The purpose of a low level cut out switch for pump protection is to protect the pump from running dry in case of
make-up failure or extreme water loss. The status of the alarm can be checked prior to pump start-up, but should
not be considered during the first minute after start-up, since activation of the pump can cause a water level drop,
that might trigger the alarm. Normal make-up will stabilize the water level after a short period of time.
FRP propeller
At temperatures below -20°C, FRP fans should be started at reduced speed to assure their structural integrity.
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