G-0400 REFRIGERANT FIELD
CONVERSION PROCEDURE
R-502 to R-402B
FOR MODELS
GR-0400A GR-0401W GR-0490N
GD-0402A GD-0403W GD-0492N
GY-0404A GD-0405W GY-0494N
retrofit refrigerant. Other
replacement refrigerants
may cause poor performance
and/or component failure.
WARNING!
Use only R-402B as
EQUIPMENT MODIFICATION REQUIREMENTS
Component Change Required
Compressor None (replacement compressor is precharged with POE oil)
Expansion Valve (TXV) None
High Pressure Cut-out None
Low Pressure Cut-out (Remotes) None
Fan Cycling Control (Air-cooled) None
All Solenoid Valves None
Water Regulating Valve (Water-cooled) None
Heat Exchanger None
Electrical Wiring None
Branch Circuit Fuse Size None
Air-cooled Condenser None
Water-cooled Condenser None
Evaporator None
SYSTEM PERFORMANCE AFTER CONVERSION
Daily Ice Production Energy Efficiency
G-0400 8% increase 5% increase
Operating discharge (high) pressure: air-cooled models will run 20-30 psig (138-207 kPa gauge)
higher than R-502 pressures published in service manuals. Set water-cooled head pressure the same
as R-502 settings.
Operating suction (low) pressure: will run 1-3 psig (7-21 kPa gauge) higher than R-502 pressure
published in service manuals.
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Manitowoc Equipment Works
Division of The Manitowoc Company, Inc. • 2110 South 26 Street, P.O. Box 1720, Manitowoc , WI 54221-1720 USA
Telephone 414-682-0161 • Fax - Sales: 414-683-7589 • Service/Parts: 414-683-7585 • Other: 414-683-7879
CONVERSION INSTRUCTIONS
1. Recover R-502 refrigerant from the ice machine in accordance with local and national governing laws.
2. Refer to “Equipment Modification Requirements” checklist on previous page.
3. Remove and replace liquid line filter drier. Use only Manitowoc approved OEM filter drier, P/N 8930233.
NOTE: compressor oil does not require changing.
4. Evacuate the ice machine. IMPORTANT: remote models require a 4-point hose hookup to evacuate
properly (refer to service manual or service bulletin, SB-18-84, for proper evacuation procedure).
5. Charge ice machine with R-402B refrigerant. System charge is identical to R-502 charge listed on
model/serial number tag. NOTE: charge with liquid only into the high side of the ice machine using
weigh-in method or “Dial-A-Charge” (refer to service manual or service bulletin, SB-18-84, for proper
charging procedure).
6. Remove purple R-502 label near service valves. Do not remove model and serial number tags!
7. Attach an R-402B conversion label, P/N 8134423, to each of the two locations:
A. Next to the serial number plate.
B. Next to the service valves.
IMPORTANT: write service company name and conversion date on each label.
8. Restart ice machine and verify it operates properly (refer to service manual, if necessary). Water-cooled
models maintain head pressure at the same R-502 setting.
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