Manitowoc QD0202A, Service Manual

Page: 161 / 175

Section 7 Refrigeration System
Part No. 80-1100-3
7-49
NORMAL REMOTE MODEL PROCEDURES
Refrigerant Recovery/Evacuation
Do not purge refrigerant to the atmosphere. Capture
refrigerant using recovery equipment. Follow the
manufacturer’s recommendations.
CONNECTIONS
Make these connections:
• Suction side of the compressor through the suction
service valve.
• Discharge side of the compressor through the
discharge service valve.
• Receiver outlet service valve, which evacuates the
area between the check valve in the liquid line and
the pump down solenoid.
• Access (Schrader) valve on the discharge line quick-
connect fitting, located on the outside of the
compressor/evaporator compartment. This
connection evacuates the condenser. Without it, the
magnetic check valves would close when the
pressure drops during evacuation, preventing
complete evacuation of the condenser.
NOTE: Manitowoc recommends using an access valve
core removal and installation tool on the discharge line
quick-connect fitting. This permits access valve core
removal. This allows for faster evacuation and charging,
without removing the manifold gauge hose.
REMOTE RECOVERY/EVACUATION
1. Place the toggle switch in the OFF position.
2. Install manifold gauges, charging cylinder/scale, and
recovery unit or two-stage vacuum pump.
3. Open (backseat) the high and low side ice machine
service valves.
4. Open the receiver service valve halfway.
5. Open high and low side on the manifold gauge set.
6. Perform recovery or evacuation:
A. Recovery: Operate the recovery unit as directed
by the manufacturer’s instructions.
B. Evacuation prior to recharging: Pull the system
down to 250 microns. Then, allow the pump to
run for an additional hour. Turn off the pump and
perform a standing vacuum leak check.
NOTE: Check for leaks using a halide or electronic leak
detector after charging the ice machine.
7. Refer to Charging Procedures.
Important
Manitowoc Ice, Inc. assumes no responsibility for
the use of contaminated refrigerant. Damage
resulting from the use of contaminated refrigerant is
the sole responsibility of the servicing company.
Important
Replace the liquid line drier before evacuating and
recharging. Use only a Manitowoc (O.E.M.) liquid
line filter drier to prevent voiding the warranty.
Important
Recovery/evacuation of a remote system requires
connections at four points for complete system
evacuation. See the drawing on next page.