Scotsman NME1854R - Manual (Page 34)

REFRIGERATION SYSTEM SERVICE
NME1854R & FME2404R
January 2000
Page 34
General: This ice machine uses R-404A refrigerant
and polyolester oil. Do NOT use mineral oil in this
refrigeration system.
· When the system is serviced, a special liquid
line drier is required. It is included with
replacement compressors.
· R-404A is not compatible with mineral oil so
these ice machines use Polyolester oil.
Polyolester oil absorbs water very easily. A
system opened for service must be re-sealed as
soon as possible (15 minutes maximum).
· Special leak detection equipment is required to
locate small refrigerant leaks. Usually a leak
detector capable of detecting a Halongenated
refrigerant or HFC-134a will work. Check with
the leak detector manufacturer if in doubt.
· Evacuate to 300 microns.
· Liquid charge the system
Access Valves: To use the access valves:
· Remove the cap from the stem, use a 3/16"
allen wrench to check that the valve is
CLOSED. The remove the core cap.
· Close the valve and replace the caps when
done. The valve must be closed and the caps
must be on or the valve will leak.
CHARGING PROCEDURES
Extra care must be taken when recharging this
remote system. No liquid refrigerant maybe placed
in the system at the compressor. DO NOT use the
valves at the front of the unit for weighing in the
charge. All liquid refrigerant must be weighed into
the receiver through the “front seated” king valve.
KING VALVE
SERVICE PORT
CHARGING
CYLINDER or
SCALE
RECEIVER
Head Pressure Control Valve
1. Purge system of refrigerant
2. Break off process tube on the top of the OLD
head pressure control valve.
3. Unsweat old valve from tubing.
4. Unsweat old dryer from tubing.
5. Install new valve in place, check for correct
connections and be sure the number on the side of
the valve is “180"
6. Wrap the new valve body in wet cloths to heat
sink the valve body.
7. Sweat in the new valve and the new dryer.
8. Evacuate the system, and weigh the nameplate
charge into the receiver.