Nilfisk-ALTO NEPTUNE 5 FA, Service Manual

Page: 31 / 63

D
31
Function
NEPTUNE 5 FA_EN_Ver.2.0_25/11
D
G
E
H
C
B
A
F
I
J
A: Hose connection/valve seat.
B: Non
return valves.
C:
Inlet for water from water supply.
D:
Magnet piston for reed switch E
E: Reed switch for start of motor/pump.
F:
Water inlet from pump.
G: Non
return valve/magnet piston for H
H:
Reed switch for start of heating
system.
I: Water
outlet.
J:
Back flow restriction.
Water supply connected to the machine:
Water from supply passes the non-return valves ”B” and lift up the piston ”D”.
Machine started in cold/hot water mode:
When piston ”D” is lifted up by the flow, the magnet in piston ”D” closes the reed contact NO ”E”
which gives a signal to the PC board, which starts up the motor/pump unit. The flow from the pump
lifts up piston ”G”. To secure the flow is all right, the magnet in piston ”G” closes the reed contact NC
”H” which gives the signal to the PC board. In hot water mode this signal controls the fuel solenoid
valve and the anti scale pump.
The fuel solenoid valve and the anti scale pump will activate when the PC board receives the signal
from reed contact ”H”.
Piston ”G”: When the gun is closed, piston ”G” closes the inlet of the flow control. Inside the piston
there is a retaining valve which opens when the outlet pressure in the flow control is more than10
bar higher than the inlet pressure, when the gun is released. This pressure differens will improve the
movement of piston ”G” when the gun again is activated.
Fig.D.9: Flow control