H .W . Flow Switch, Filter And Flow Limiter; Function; Description And Location Of Parts; Removal Of The Sensor - Biasi RINNOVA ADAPTIVE M300V.2025 SM Service Manual

D.H.W. FLOW SWITCH, FILTER AND FLOW LIMITER
14 D .H .W . FLOW SWITCH, FILTER AND
FLOW LIMITER

14 .1 Function

The D.H.W. flow switch "A" in Figure 14.1 is a device that gener-
ates an electrical signal when hot water is drawn.
Figure 14 .1
When the flow rate through the D.H.W. circuit reaches about 2,5
litres/min', the sensor closes the electric contact that switches
the boiler D.H.W. operation ON.
14 .2 Description and location of parts - (Figure
14 .2 - Figure 14 .3)
The flow limiter is inserted inside the delivery connection of the
D.H.W. heat exchanger.
1 Flow switch plug
2 Body with flow meter turbine
3 O-ring
4 Sensor
5 Filter
1 2 3
Figure 14 .2
5
Figure 14 .3

14 .3 Removal of the sensor

A
Figure 14 .4
1 Remove the front panel of the case.
2 Remove the sensor holder "B" (Figure 14.4) and disconnect
3 Remove the sensor.

14 .4 Checks

4
Figure 14 .5
1 Remove the front panel of the case.
2 Don't disconnect the connectors "C".
3 Measure the electrical frequency at the leads of the sensor.
Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
B
the connectors "C" (Figure 14.5).
Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
Sensor operation
rd
5V
C
B
C
Without flow rate the electrical frequency must be 0÷32Hz.
With flow rate the electrical frequency must be 33÷200Hz.
wh
bu 0..32 Hz
(without flow rate)
33..200 Hz
(witht flow rate)
wh
bu
rd
wh = white
bu = blue
rd = red
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