H .W . Flowmeter, Filter And Flow; Limiter; Function; Description And Location Of Parts - (Figure 14.2) - Biasi RIVA PLUS HE 24C ERP 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 .
- 32 -
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