MAINTENANCE & REPAIR
31
ENTERING THE SYSTEM
Entering the system should only be done as a last
resort. Extreme care must be used no matter what the
reason is for entering the system. Of course there are
times it cannot be avoided, such as component or
compressor replacement, or a leak within the system.
The system must also be entered any time you need
to obtain the operating pressures. Again, use extreme
caution to avoid any possible contamination.
Cabinets that use semi-hermetic compressors allow
easy access through the valve ports.
Cabinets using hermetic compressors do not have
valve ports, this product has process stubs for both
suction and discharge sides of the system.
Line taps should only be used to obtain pressure
readings, and not for reprocessing a system. The
opening of a line tap is too restrictive for pressure of
vacuum procedures.
Install hand valves at the process stub ends. Hand
valves will be less restrictive to flow because of a
larger opening. They will also be easier to use during
repair procedures.
EVACUATION
Once the system has been cleaned and components
have been replaced, you are ready to initiate the final
servicing procedures necessary to achieve proper
cabinet operation.
Pull an evacuation to approximately 50 microns. You
can be sure that any contaminants that can affect the
system’s operation are now removed.
Use this time to check any joints for potential leaks.
CHARGING
You should use a charging cylinder to measure in the
the correct amount of refrigerant. The charging
methods are:
1) Add the refrigerant to the system until you reach a
predetermined balanced pressure. This will give you
an approximate static charge.
2) Weigh in the refrigerant using a scale calibrated in
ounces.
The cabinet’s operation is now ready to be tested. A
final check of the refrigeration lines should be made
before running the cabinet.
Be sure the refrigeration lines are not kinked or
rubbing against each other.
Also check that the door seals properly. An air leak will
affect proper operation, and the cabinet’s ability to
reach its coldest temperature.
Run the cabinet a both 100% run and also at a
cycling temperature for at least one day. If the
temperature and pressures are correct, the system
can be considered repaired.
Hermetic systems should now have their process
stubs pinched off, hand valves removed and the ends
brazed shut.
Dipping Cabinet 1298.02 2/3/03 1:14 PM Page 33
Summary of Contents for R-404A
Page 3: ...Introduction...
Page 13: ...SECTION II Principles of Operation...
Page 14: ......
Page 28: ......
Page 29: ...SECTION III Maintenance Repair...
Page 55: ...PARTS LISTING With Illustration Identification...
Page 56: ...CABINET PARTS EXPLODED VIEW 54 CABINET PARTS EXPLODED VIEW 2 1 3 4 7 9 8 6 10 11 5...
Page 60: ...CONDENSING UNIT EXPLODED VIEW 58 CONDENSING UNIT EXPLODED VIEW...
Page 62: ...ELECTRICAL PARTS EXPLODED VIEW 60 ELECTRICAL PARTS EXPLODED VIEW...
Page 64: ...1 6 7 2 4 3 5 LID EXPLODED VIEW 62 LID EXPLODED VIEW...
Page 66: ......
Page 67: ...ACCESSORIES...
Page 68: ......
Page 73: ...ADJUSTABLE LEG KIT 52 1831 01 ACCESSORIES 71...
Page 74: ...CASTER KIT 52 1830 01 72 ACCESSORIES...
Page 76: ...CAN CLAMP INSTALLATION 74 ACCESSORIES...
Page 79: ......
Page 80: ...by National Refrigeration Products 563 Corbin Road Honea Path South Carolina 800 486 8369...
