27
SKOPE OD1100N
Replacement Procedures
Service Manual
Hydrocarbon leak detector
Refrigeration gauge set – suitable for flammable hydrocarbon refrigerant
Dry nitrogen – suitable for purging and high pressure testing
Intrinsically safe refrigeration vacuum pump, rated by the manufacturer as suitable for use
with hydrocarbon refrigerant
Charging scales, rated by the manufacturer as suitable for use with hydrocarbon
refrigerant, accurate to 1 gram
Hydrocarbon refrigerant supply cylinder
Diagnosing
Lack of Gas
The following test is useful to do in a hydrocarbon-compliant workshop (see “Off
page 26) to work out if the system is short of gas. Always perform it before opening the
refrigeration system.
It is helpful to have a correctly operating cartridge running beside the cartridge being serviced
to compare behaviour.
Note
: This diagnostic procedure is indicative only.
Refrigeration Cartridge
The refrigeration cartridge is a bottom-mounted, electronically controlled (see page 10),
removable cartridge.
For servicing or transportation, the refrigeration cartridge unplugs and pulls out of the cabinet.
For safety and compliance, only repair the cartridge with SKOPE
-
supplied parts made
specifically for this cabinet. Other parts may appear to be suitable, but may not be approved
or safe for use in a fridge with hydrocarbon refrigerant.
Procedure 15: To diagnose lack of gas
1. Disconnect the cabinet from the power supply (see page 18).
2. Remove the refrigeration cartridge (see page 28).
3. Move the control probe outside the evaporator tub.
4. Remove the cartridge’s right panel.
5. Disconnect the evaporator fan motor (white plug).
6. Fit a temperature probe to the evaporator inlet tube.
7. Fit a temperature probe to the compressor suction pipe.
8. Connect the cartridge to a power supply.
9. Use the run test below to check the system performance. If there is no frost at all at the
evaporator inlet tube there may be a capillary blockage or compressor fault.
10. After the fault has been diagnosed and repaired, reassemble the refrigeration system and test
run.
Table 5: OD1100N Series (cartridge UBQENI-0052)
Time
1 min
2 min
3 min
4 min
5 min
6 min
Evaporator inlet tube (°C)
-14
-22
-26
-28
-28
-20
Compressor suction pipe
(°C)
16
0
-23
-27
-28
-22
Current (amps)
2.7
2.4
2.3
2.3
2.3
0.1
Suction frost
cold
cold
wet
soft ice
soft ice
soft ice
Compressor frost
wet
soft ice
70 mm soft ice
Compressor start
16 sec
on
on
on
on
defrost
