Thermo King CRR-40 119, Manual

Page: 145 / 170

Refrigeration Maintenance and Service Operations
145
Liquid Line Solenoid Valve
Replacement
Removal
1. Close the liquid line service valve and pump
down the low side to -35 kPa, -0.35 bar, 10 in.
vacuum. Break the vacuum with nitrogen
between 10 and 20 kPa, 0.10 and 0.20 bar, 1
and 3 psig.
2. Turn the unit On-Off switch OFF. Disconnect
electrical connections to liquid line solenoid.
NOTE: In most cases, only the coil requires
replacement. No other repair is possible on
the liquid line solenoid.
3. Unsolder the liquid line connections from the
valve.
4. Remove the valve from the unit.
Installation
1. Clean the tubes for soldering.
2. Place the new valve in position and solder the
connections.
3. Release a small amount of refrigerant from the
receiver tank to pressurize the liquid line.
Check for leaks (see “Refrigerant Leak Test
Procedure” in the Refrigeration Maintenance
chapter of this manual).
4. If no leaks are found, recover the leak test gas
(see “Refrigerant Recovery” in the
Refrigeration Maintenance chapter of this
manual).
5. Evacuate the low side (see “Evacuation and
Cleanup of the Refrigeration System” in the
Refrigeration Maintenance chapter of this
manual).
6. Reconnect the electrical wires to the valve.
7. Open the liquid line service valve and place
the unit in operation. Check the refrigerant
charge and add refrigerant as required.
Liquid Injection Valve Replacement
Removal
1. Close the liquid line service valve and pump
down the low side to -35 kPa, -0.35 bar, 10 in.
vacuum. Break the vacuum with nitrogen
between 10 and 20 kPa, 0.10 and 0.20 bar, 1
and 3 psig.
2. Disconnect the unit power source from the
unit. Disconnect the electrical connections to
the liquid injection valve.
NOTE: In most cases, only the coil requires
replacement. No other repair is possible on
the liquid injection valve.
3. Unsolder the liquid line connections.
4. Unbolt and remove the valve from the unit.
Installation
1. Clean the tubes for soldering.
2. Place the new valve in position.
3. Solder the liquid line connections.
4. Pressurize the low side with refrigerant and
check for leaks (see “Refrigerant Leak Test
Procedure” in this chapter).
5. If no leaks are found, recover the leak test gas
(see “Refrigerant Recovery” in this chapter).
6. Evacuate the low side (see “Evacuation and
Cleanup of the Refrigeration System” in this
chapter).
7. Reconnect the electrical wires to the valve.
8. Open the liquid line service valve and place
the unit in operation. Check the refrigerant
charge and add refrigerant as required.
CAUTION: Use a heat sink or wrap the
valve with wet rags to prevent damage to
the new valve.
CAUTION: Use a heat sink or wrap the
valve with wet rags to prevent damage to
the new valve.