Alto Neptune 5, Руководство по обслуживанию, Страница: 22 / 61

4.
Function
Neptune_GB_Ver.2.0_10/03
B4
20.
Control Safety Block 1
Flow switch B2. NO
Magnet piston
HP hose to boiler
Low volume adjustment
Main ajustment nut
Fine adjustment screw
Low volume spring
Unloader spring
Microswitch B4. NC
Unloader valve piston
Safety valve
Non-return valve
Water inlet suction side
HP outlet from pump
Unloader valve seat
When the machine is started with a closed spray gun:
The pressure rises until the cutoff pressure is reached (set by the
unloader spring). The unloader valve piston is forced upwards
and will open the microswitch B4, which signals the PCB A1 to
start the timer which will stop the machine in 20 s. During that 20
s, the water being pumped will flow through the unloader valve
seat and return to the pump. Also during the initial start, water is
pressurized in the heat exchanger, the high pressure hose, and
the HP chamber under the unloader valve piston. When the
unloader valve opens, there is a lower pressure in the green
area, and the non-return valve is forced onto its seat, trapping
high pressure in the heat exchanger and HP hose. When the
pump stops, pressure in the green area goes to 0 bar.
High
pressure is shown with blue in this drawing and low or no
pressure, with green.
When the spray gun trigger is squeezed, the pressure trapped in
the heat exchanger and HP hose is reduced and the unloader
spring forces the piston down, allowing the microswitch B4 to
close, which signals the PCB A1 to start the pump motor.
You can also see in this drawing that the magnet piston has
moved up with water flow and will signal the PCB A1 to turn on
the burner if hot water is selected.
The safety valve will only open if the pressure in the system
exceeds P
10 %, such as might be caused by a blocked
unloader valve.
max
+
B4
ON
B4
B2
B2