Refrigeration Service - Scotsman CME650 Service Manual

REFRIGERATION SERVICE

General:
Scotsman recommends that any work on the
refrigeration system only be done when it is
certain that the system needs repair. Use
conservation minded service procedures:
Refrain from checking refrigeration
pressures without reason. There are many
ways to determine the proper operation of a
Scotsman ice machine without using refrigerant
gauges. Visual inspection of the water system,
observation of the ice formation, amp draw,
voltage, and other techniques will lead to proper
diagnosis. Scotsman also recommends that, at
the time of initial start up, gauges not be used.
Refrigerant should not be added except as a
way to determine the proper operation of the
product. If the system was low on refrigerant,
there is a leak, and it must be found and
repaired.
Refrigerant should not be wasted to the
atmosphere.
This system has a critical charge, it must be
recharged with the correct amount of refrigerant
as listed on the nameplate of the ice machine,
or performance will suffer.
Anytime the refrigeration system has been
opened, the dryer should be replaced. Note:
Only a HFC type dryer should be used.
When brazing the tubing connections to the hot
gas valve, the component must be protected by
heat sink material.
If gauges must be used, do not always
check the high side pressure. If the
condenser is clean and seems to be operating
correctly, it most likely is. The low side pressure
is much more important on an ice machine than
is the high side.
If gauges must be used, use very short hoses.
Minimal refrigerant discharged into the hoses
equals minimal refrigerant discharged into the
air.
Recover, reclaim or recycle refrigerant.
The method chosen is up to the service company.
There are various mechanical devices that may be
used to recycle refrigerant at the field level,
however, Scotsman requires that any refrigerant
placed into a Scotsman ice machine meet ARI
spec 700-88. Reclaim programs are available
through most refrigerant wholesalers.
Access Valves: To use the access valves:
Remove the cap from the stem of the valve, then
use a 3/16" allen wrench to check that the valve is
closed. The core cap may then be removed.
Close the valve and replace the caps when the
Torque Stem
Cap to 8-12 ft. lb.
Allen
Wrench
job is finished. The valve must be closed and
the caps must be on or the valve will leak.
October 1994
Page 23
CME650
Torque Stem
Torque Core
to 6-8 ft. lb.
Access Valves
Note: There are no Schrader
valve cores in the valve.
Cap to 7-12
ft. lb.