RS5280001 Rev. 0
36
To avoid death or severe personal injury, never use
oxygen, air or acetylene for pressure testing or
clean out of refrigeration system. Use of oxygen,
air, or acetylene may result in violent explosion.
Oxygen may explode on contact with oil and
acetylene will spontaneously explode when under
pressure.
Replacement Service Compressor
HFC134a service compressors will be charged with
ester oil and pressurized with dry nitrogen. Before
replacement compressor is installed, pull out 1 rubber
plug. A
pop
from pressure release should be heard. If
a
pop
sound is not heard, do not use compressor.
Positive pressure in compressor is vital to keep
moisture out of ester oil. Do not leave compressor
open to atmosphere for more than 10 minutes.
Compressor Testing Procedures
Refer to Technical Data Sheet “Temperature
Relationship Chart” for operating watts, test points,
and temperature relationship test for unit being tested.
• Temperature testing is accomplished by using 3 lead
thermocouple temperature tester in specific locations.
Test point T-1 is outlet on evaporator coil and T-2 is
inlet. Test point T-3 is suction tube temperature
midway between where armaflex ends and suction
port of compressor (approximately 30cm from
compressor).
• Thermocouple tips should be attached securely to
specified locations.
• Do not test during initial
pull down
. Allow one off cycle
or balanced temperature condition to occur before
proceeding with testing.
• Refrigerator must operate minimum of 20 minutes
after thermocouples are installed.
• Turn control to colder to obtain required on time.
• Wattage reading must be recorded in conjunction with
temperature test to confirm proper operation.
• Suction and head pressures are listed on
“Temperature and Relationship Chart” Normally these
are not required for diagnosis but used for
confirmation on systems which have been opened.
Service Procedures
To avoid risk of electrical shock, personal injury, or death, disconnect electrical power source to unit, unless test
procedures require power to be connected. Discharge capacitor through a 10,000 ohm resistor before attempting
to service. Ensure all earthing wires are connected before certifying unit as repaired and/or operational.
!
WARNING
Brazing
CAUTION
!
To reduce risk of personal injury or property
damage, take necessary precautions against high
temperatures required for brazing.
Satisfactory results require cleanliness, experience,
and use of proper materials and equipment.
Connections to be brazed must be properly sized, free
of rough edges, and clean.
Generally accepted brazing materials are:
•
Copper to copper joints
: SIL-FOS
(alloy of 15
percent silver, 80 percent copper, and 5 percent
phosphorous). Use without flux. Recommended
brazing temperature is approximately 760°C (1400°F).
Do not use for copper to steel connection.
•
Copper to steel joints
: SILVER SOLDER
(alloy of 30
percent silver, 38 percent copper, 32 percent zinc).
Use with fluoride based flux. Recommended brazing
temperature is approximately 649°C (1200°F).
•
Steel to steel joints
: SILVER SOLDER (see copper
to steel joints).
•
Brass to copper joints
: SILVER SOLDER (see
copper to steel joints).
•
Brass to steel joints
: SILVER SOLDER (see copper
to steel joints).
Checking Electric Heater Assembly
1.
Disconnect power to unit.
2.
Ensure heater element is cold, then remove
suspect heater and visually inspect element for
obvious damage (breaks, cracks in element, etc.).
3.
Attach ohmmeter to element leads. Check for
continuity (see technical data sheet for unit under
test).
If element reads open (infinite or very high resistance):
4.
Check disc type thermostat for continuity (see
technical data sheet for open and close values). If
open replace.
WARNING
!
