14 D.h.w. Flowmeter, Filter And Flow Limiter; Function; Description And Location Of Parts - (Figure 14.2); Removal Of The Sensor - Biasi Riva Plus HE M296.24SM/C Service Manual

d.H.W. floW SWiTCH, filTER ANd floW liMiTER
14 d.H.W. floWMETER, filTER ANd floW liM-
iTER

14.1 function

The d.h.w. flowmeter A in Figure 14.1 is a device that generates
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)

1
2
3
figure 14.2
1 Flow switch plug
2 O-ring
3 Flow limiter (optional accessory)
4 Body with flow meter turbine
5 Filter

14.3 Removal of the sensor

Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
figure 14.3
1 Remove the front panel of the case.
2 Disconnect the connectors B and remove the sensor holder
A
3 Remove the sensor.

14.4 Checks

5
4
2
figure 14.4
1 Remove the front panel of the case.
2 Don't disconnect the connectors B
3 Measure the electrical frequency at the leads of the sensor.
14.5 Removal of the flow switch group and d.h.w. cir-
E
d
C (Figure 14.3).
Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
Sensor operation
0..32 Hz
(without flow rate)
33..200 Hz
(witht flow rate)
wh = white
bu = blue
rd = red
Without flow rate the electrical frequency must be 0÷32Hz.
With flow rate the electrical frequency must be 33÷200Hz.
cuit filter
Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
b
C
bu
wh
rd
b
5V
rd
bu
wh
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