Refrigeration Maintenance
10-6
The ball in the sight glass should be floating. If there is no indication of refrigerant in the sight glass, the unit is low on
refrigerant. For category B SLX, open doors to view the sight glass and close again
NOTE: If the ball floats, there is sufficient refrigerant in the unit for that load at that particular compartment temperature.
This test does not determine if the unit contains a full charge of refrigerant.
Refrigerant Overcharge Check
Use the following procedure to identify a system with an excessive refrigerant charge:
1. Install a calibrated gauge manifold on the compressor.
2. Operate the unit in high speed COOL to stabilise system pressures and reduce the compartment temperature to approximately
16 C or colder. Also operate all remote evaporators on COOL to reduce the compartment temperature to 16 C.
3. Observe the discharge pressure and cover the condenser grille to increase the discharge pressure 5.20 to 6.90 bar, 75 to 100 psi
above the observed pressure. On SL, SLe models, the condenser grille is located above the unit control panel. For SLX, SLXe
and SLXi, it is located on the side of the unit, above the control panel.
NOTE: If the ball and liquid level in the sight glass decline during this step, the unit is not overcharged. You do not need to
continue this test.
4. Remove the condenser cover to rapidly reduce the discharge pressure.
Note: Momentarily open doors for this check
5. Observe the receiver tank sight glass(es) and the unit’s discharge pressure.
When the discharge pressure decreases approximately 3.45 bar, 50 psi; the ball in the sight glass should move and the liquid
level should decline. When the discharge pressure stabilises, the ball and liquid level will rise to the previous level. If the
liquid level declines during this test, the refrigerant charge is correct.
If the ball does NOT move or liquid level does NOT decline, the unit has an overcharged of refrigerant. Remove refrigerant
to reduce the refrigerant charge.
To remove refrigerant:
1. Connect and purge/evacuate a gauge manifold set to the receiver tank outlet valve and an approved sealed container.
2. Operate the unit in high speed COOL (and the remote evaporators in COOL).
Note: For Category B unit, close all doors on unit and ensure all unit panels and skins are securely attached.
3. Use a gauge manifold set from step 1 to pump refrigerant from the receiver tank into the approved sealed container.
4. When the liquid level begins to decline in the receiver tank sight glass (bottom sight glass on two sight glass receiver tank),
close the hand valve on the gauge manifold immediately. Allow the new liquid level in the sight glass to stabilise (1 to
2 minutes).
Note: For Category B unit, close all doors on unit and ensure all unit panels and skins are securely attached.
• If the refrigerant level is still high, repeat steps 2 through 4.
• If the refrigerant level is now low, add refrigerant to the unit (see below).
• If the refrigerant level is ok, perform a complete refrigerant level check and repeat the overcharge test.
5. Always recover remaining refrigerant from the hoses before disconnecting the gauge manifold set from the unit.
Summary of Contents for SLXi Spectrum
Page 17: ...Safety Precautions 2 5 Warning Decals...
Page 18: ...Safety Precautions 2 6 Warning Decals Information Decals...
Page 74: ...Unit Description 5 30...
Page 128: ...Controller Operation 7 28...
Page 156: ...Electrical Maintenance 8 28...
Page 234: ...Refrigeration Maintenance 10 22...
Page 309: ...13 Mechanical Diagnosis TK 482 TK 486 and TK 486V Engines 13 2...
Page 316: ...Mechanical Diagnosis 13 8...
Page 322: ...Refrigeration System Diagnosis 14 6...
Page 332: ...Single Temperature Refrigeration System Diagrams 15 10...
Page 339: ...Multi Temperature Refrigeration System Diagrams 16 7...
Page 340: ...Multi Temperature Refrigeration System Diagrams 16 8...