Edwards TCU 40/80 - Page 34

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7.7 Semi-annual preventative maintenance
Refer to the Troubleshooting section on page 42 when results for any of the following checkpoints are
not as expected.
7.7.1 Required equipment
• 12" slotted screwdriver • Spare lamps (24 vac / 60 mA)
• 4" slotted screwdriver • Fluorinert
• Two 10" adjustable wrenches • Insulation Tape
• Halogen leak detector
7.7.2 Preparation
• Locate the two screws securing each of the side access panels and loosen to open doors.
• Listen for excessive or questionable noise or sounds coming from the pump assembly, motor,
compressor, or solenoid valves (SV1 and SV2).
7.7.3 Verify system status
• Verify system status led indicators on the front electrical panel. (See - Front panel power up
indicator conditions table on page 20.)
7.7.4 Refrigeration leak check
• Visually check for signs of compressor oil on the base, insulation, and on all refrigeration pipework.
• Using a halogen leak detector check around the discharge and suction service valves of the
compressor, and all accessible refrigeration pipework.
7.7.5 Fluorinert leak check
• Use a halogen leak detector to check all supply and return line connections at both the TCU and
process equipment, around the pump head assembly, drain valve, heater, flow switch, vent line, fill
line, and reservoir pressure relief valve.
7.7.6 Water leak check
• Visually check for signs of water leaks at all water line connections external to the TCU and at the
condenser connections inside the unit.
7.7.7 Insulation repair
Note: If ice formation is excessive, it may be necessary to correct this condition before insulation can be
repaired.
• Visually inspect refrigeration and process fluid lines both inside the TCU cabinet and at the supply
and return line connections for signs of ice formation. Correct insulation as necessary.
28 TCU 40/80 Temperature Control Unit