Solenoid - Stoelting F231 Service Manual

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5.7 SOLENOID

Solenoid valves are installed on the liquid and suction
lines of each freezing cylinder evaporator and on the liquid
line of the hopper evaporators (Refer to Figure 5-10 and
Figure 5-11). A solenoid valve has a magnetic coil that,
when energized, lifts a plunger and allows refrigerant to
fl ow. The solenoids are activated by the IntelliTec control
and determine which evaporator receives refrigeration.
The suction line solenoid prevents refrigerant fl ow in the
evaporator when the suction pressure drops due to the
operation of the other evaporators in the system.
ACTIVATING A SOLENOID
To open a solenoid, follow these steps:
A. Turn the machine on by pressing the Main Power
Off/On button.
B. Press the right arrow, SET, then the SEL button
to access the technician level on the control.
C. Navigate to the Left Output Control or Right Output
Control menu which is located under Utilities in
the Testing and Manual Operation screen. Refer
to Section 4 for details.
D. Activate the solenoid by moving the cursor to
the Liquid Solenoid option and pressing the SET
button.
Any energized component will deenergize after
leaving the Testing and Manual Operations menu.
SUCTION LINE SOLENOID TESTING
To check for leaking valve seats, follow the procedure
outlined below. The liquid line solenoid must remain open
for this test.
Machine barrels must NOT contain frozen product
for this test.
A. Turn the machine off by pressing the Main Power
On/Off button.
B. Attach a gauge to the Schrader valve located
after the evaporator of the side being tested.
C. Turn the machine on by pressing the Main Power
Off/On button.
D. Turn the opposite side Freezing Cylinder on by
pressing the On/Off Left or On/Off Right button.
If checking the solenoid on the left side, press the
On/Off Right button. For the right side, press the
On/Off Left button.
E. Start a freezing cycle of the opposite side by
pressing the Push To Freeze button or by pulling
the spigot handle.
NOTE
NOTE
NOTE
Figure 5-10 Liquid Line Solenoid Valve
Figure 5-11 Suction Line Solenoid Valve
F. If the pressure drops more than 3 psi in 30 seconds
on the side being tested, the suction line solenoid
valve seat leaks and should be replaced. Repeat
the procedure for the other side.
LIQUID LINE SOLENOID TESTING
The following test will check if a liquid line solenoid has
a leaking valve seat. The power to the solenoid is dis-
connected and refrigerant fl ow is monitored through the
system. If the valve seat does not leak, the suction pres-
sure during the test will be low.
A. Attach a gauge to the Schrader valve on the
suction line.
B. Turn the machine on by pressing the Main Power
Off/On button.
C. Press the right arrow, SET, then the SEL button
to access the technician level on the control.
D. Navigate to the Left Output Control or Right Output
Control menu which is located under Utilities in
the Testing and Manual Operation screen. Refer
to Section 4 for details.
E. Activate the compressor by moving the cursor
to the compressor option and pressing the SET
button.
F. The gauge should read well below 21 psig after
1 minute.
G. A leaking valve seat may also show frost on the
liquid line tubing just past the solenoid and before
the evaporator.
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