Adjustments
The flow switch comes with a factory pre-set setting. Due to the different applications at site, it
may be necessary to perform some adjustments to the flow switch to allow it to function properly.
Such adjustments are done to cater for the flow rate requirements. To do this, turn the adjustment
screw clockwise or anticlockwise with a screwdriver. For the F61 switch, this screw is located next
to the SPDT switch. What this screw does is to adjust the spring tension which holds the switch
together.
Turning the screw clockwise will release the spring tension, therefore, a lesser flow rate will
activate the switch. Conversely, turning the screw anticlockwise will increase the spring tension,
therefore a greater flow rate is needed to activate the switch.
It is recommended that during trouble-shooting of the flow switch, this screw adjustment is
checked for wrong settings which could cause the system to trip.
Weather proofing
Since the flow switch is exposed to the external elements, and also because of the wet operating
environment, it is vital that the flow switch cover is screwed on tightly and properly.
For the F61SB model, the cover comes with a piece of rubber gasket around the edges to prevent
moisture from entering the switch.
Do not remove this gasket from the cover! Make sure that the gasket is seated correctly along
the edges before the four screws are tighten.
Some flow switches have an 'inverted cup' cover which prevents entry of moisture into the switch.
Such switches do not have a gasket. Nevertheless, it is vital that the cover sits properly and the
holding screws tighten securely. Example of this is the F61KB model.
In the same manner, care must be taken that the incoming cable into the switch is sufficiently
sealed to prevent moisture from entering the switch.
Failure to do so may cause shorting of the terminals and corrosion of the internal parts of the
switch.
Section 12 Page 144
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