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Service Manual for Subway Front Counters
SERVICE INFORMATION
SERVICE BULLETIN NUMBER 26 NOVEMBER 12, 2003
REFRIGERATION SYSTEM EVACUATION PROCESS
When service of the refrigeration system is necessary, care must be giving during the evacuation process
to ensure removal of air, moisture, and other non-condensables from the system. To evacuate a system
properly, Duke
Manufacturing recommends a triple evacuation procedure outlined below. Failure to follow this process
could cause poor performance of the refrigeration system.
•
Evacuate system to 1500 microns
• Break the vacuum to 2 psig with dry nitrogen, if dry nitrogen is unavailable use the same type of
refrigerant as used in the system
•
Evacuate system to 1500 microns
• Break the vacuum to 2 psig with dry nitrogen, if dry nitrogen is unavailable use the same type of
refrigerant as used in the system
•
Evacuate system to 500 microns
•
The system is now ready to receive the refrigerant charge per the data plate information.
CAUTION: NEVER USE OXYGEN OR ACETYLENE IN PLACE OF REFRIGERANT AND DRY
NITROGEN FOR LEAK TESTING. A VIOLENT EXPLOSION MAY RESULT, CAUSING
PERSONAL INJURY OR DEATH.
ALWAYS USE A PRESSURE REGULATOR WHEN USING NITROGEN TO PRESSURE
TEST. FAILURE TO DO SO WILL RESULT IN EXTREMELY HIGH PRESSURE, WHICH
COULD EXCEED THE BURST PRESSURE OF THE COMPRESSOR OR OTHER
SYSTEM COMPONENTS AND RESULT IN PERSONAL INJURY OR DEATH.
