Miele G 7881 Service Manual

2.2 Connection to a Shutoff Valve with Spring-Loaded Valve
Fig. 2:Shutoff Valve with WaterProof Valve
–Correct function
If the on-site shutoff valve contains a spring-loaded valve (041 Fig. 2, Pos. 2),
then, even if the valve is opened, the spring can hold the valve plate closed if the
counter pressure at the valve exit (041 Fig. 2, Pos. 4) is the same as that of the
supply. When both valves in the WaterProof system open, the supply pressure
can open the valve plate (041 Fig. 2, Pos. 2) against the...

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Note
Miele washer-disinfectors are approved by the German water authority (shown
by the DVGW certification). Shutoff valves with spring-loaded valve plates are
therefore not required and can, if necessary, be replaced with non-spring-loaded
versions.
2.3 Water Paths
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Fig. 3:Water Paths–24-Inch Machine with the Maximum Number of Options
1 Non-return device
2 Softener reactivation reservoir
3 Cabinet
4 Water intake - Soft water from softener
5 Flow meter
6 Water inlet valve - Demineralized water
7 Water...

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Fig. 4:Water Paths–28-Inch Machine with the Maximum Number of Options
1 Non-return device
2 Softener reactivation reservoir
3 Cabinet
4 Water intake - Soft water from softener
5 Flow meter
6 Water inlet valve - Demineralized water
7 Water inlet valve - Hot water
8 Non-return valve
9 Water softener - Soft water output
10 Water inlet valve - Cold water
11 Water softener - Supply water intake
12 Salt container intake
13 Salt container
14 Water inlet valve - Cold water for steam condenser
15 Non-return...

2.4 WaterProof System
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Fig. 5:WaterProof System
Two independently functioning solenoid valves in the intake hose are combined to
form the WPS valve, e.g., Y1 (cold water), Y12 (hot water) and/or Y20
(demineralized water). The two valves located directly at the shutoff valve
connection are connected in series, both electrically and for water flow. This
ensures that if one valve should fail (e.g., due to blockage caused by a foreign
object) the water flow can still be switched off by the other valve if...

2.5 Water Intake, Water Diverter
Fig. 6:Water Diverter
In accordance with DVGW guidelines, the water diverter is provided with a non-
return device which prevents the possibility of a reflux of water back into the
supply should a vacuum exist.
The water intake hose from the WaterProof System (WPS) (cold/hot water) is
connected to the water diverter (041 Fig. 6, Pos. 14). Hard supply water flows past
the non-return valve (041 Fig. 3, Pos. 8) via flow meter 1B3/4 (041 Fig. 3, Pos. 5)
through the intake...

The majority of the water, blocked by the ball valve at the water reservoir inlet,
flows via the water channel (041 Fig. 6, Pos. 3) downwards to the water diverter
outlet (041 Fig. 6, Pos. 13) and then to the water softener (041 Fig. 3, Pos. 10).
After passing through the water softener, the now-soft water flows via the soft
water intake (041 Fig. 6, Pos. 10) back into the water diverter. It then flows into the
cabinet via the water intake (041 Fig. 3, Pos. 4) into the cabinet. Cabinet
ventilation is...

compared with a reactivation table (041 Table 3) stored in memory. The quantity
of demineralized water taken in, registered by flow meter 2B3/4, is not taken into
account because this water does not pass through the water softener.
For reactivation the electronic activates solenoid valve Y38 (041 Fig. 7, Pos. 8).
Supply water from the reservoir (041 Fig. 7, Pos. 6) in the water diverter then flows
into the salt container where it dissolves a quantity of salt. The brine then flows
past a mechanical...

Water Hardness Setting, °d (Degree of
German Hardness)Total Water Quantity After Which Reactivation
Will Occur (Gallons (Liters))
25 37 (140)
26 35 (131)
27 32 (122)
28 30 (113)
29 28 (105)
30 25 (96)
31 24 (91)
32 23 (86)
33 22 (82)
34 21 (78)
35 20 (74)
36 18 (70)
37 17 (66)
38 16 (62)
39 16 (59)
40 15 (56)
41 14 (53)
42 13 (51)
43 13 (50)
44 13 (49)
45 - 60 13 (48)
Table 3:Reactivation Showing Relationship Between Water Hardness and Water Quantity
In normal operation, reactivation (if required) is...

Reactivation takes place in 7 steps:
–2.5 minutes of brine flowing into ion exchanger.
–2.5 minutes of contact time for brine in ion exchanger.
–Flushing with 0.4 gallons (1.4 liters) of cold water followed by 10 seconds of
drainage.
–Flushing with 0.4 gallons (1.4 liters) of cold water followed by 10 seconds of
drainage.
–Flushing with 0.4 gallons (1.4 liters) of cold water followed by 10 seconds of
drainage.
–Flushing with 0.4 gallons (1.4 liters) of cold water followed by 30 seconds of
drainage....

2.7 Flow Meter
The incoming water rotates an impeller in the flow meter. A permanent magnet
located in the flow meter axle activates an external reed switch each time the axle
rotates. The pulses supplied by the reed switch are registered by the electronic.
Approximately 200 pulses represent 0.3 gallons (1 liter) of water. An adjustment of
the number of pulses perliteris not possible. If the flow count is not satisfied after
5 minutes, then the machine will fault out. There is also an overflow level...