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9.2
P
OTENTIOMETER
/
S
9.2.1
The potentiometer shaft is frictioned and is accessible from the upper side
inside the gear motor.
9.2.2
Disconnect the cables connected with the regulation system from the
respective terminals n. 30, 31 and 32 [Pot. A] and, if necessary, n. 33, 34 and
35 [Pot. B].
9.2.3
By means of a suitable screwdriver with 5 mm cut rotate the potentiometer
shaft and measure the resistance value of 0 Ohm between terminals n. 31 and
32 and, if necessary, also between terminals n. 34 and 35 when the valve is
closed [picture 2].
Picture
2
9.2.4
By rotating the potentiometer:
●
clockwise
3
the resistance value increases
●
counter dock wise
4
the resistance value decreases
9.2.5
The gearbox between the gear motor shaft and the potentiometer shaft is
foreseen for a 90° rotation angle between closed valve and totally open valve.
Hence should the gear motor opening be reduced with a rotation angle lower
than 90°, the variation of the potentiometer resistance value will be
proportionally reduced.
If, vice versa, the rotation angle had been wrongly adjusted over 90° there
will be no increase in the resistance value beyond the plate maximum value.
