Danfoss Turbocor TT Series Service Manual page 257

Compressor Status
Trigger Method
Description
Low Leaving Fluid DFT
Temperature Fault
High Pressure Ratio AFT
Fault
Bearing/Motor Fault INS
Active
Sensor Fault RFT
High SCR AFT
Temperature Fault
Troubleshooting
faults.
Recommendation:
Ensure the liquid motor-cooling line has sufficient liquid supply and is not blocked.
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Prevent prolonged operation at a pressure ratio less than 1.5.
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o Low Lift operation requires additional considerations, refer to Applications
Manual
Verify the solenoids are operational and not blocked. Refer to Section 4.6.3 S olenoid
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Verification on page 73.
Verify the solenoid actuators. Refer to Section 4.6.3 S olenoid Verification on page 73.
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Verify the Serial Driver. Refer to Section 4.26.3 S erial Driver Verification on page 217.
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Verify cavity temperature sensor. Refer to Section 4.31.3 C avity Temperature Sensor
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Verification on page 242.
(Removed from CC 4.X.X software)
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Suggests insufficient evaporator fluid flow or insufficient system load.
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Check evaporator fluid flow and system load.
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Verify leaving fluid temperature sensor.
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Ensure LEAVE jumper is installed on the I/O board.
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Review the fault log for entering and leaving air/water temperature (if available) and
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other conditions that are recorded at the time of fault.
Suggests the condenser ressure is high, not enough load on the evaporator, or
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insufficient water/air flow in either condenser or evaporator.
Check the electronic expansion valve (EXV) operation, condenser, evaporator loads, and
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water/air flow.
Review the fault log for suction and discharge pressures and other conditions that are
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recorded at the time of fault.
If a Motor Fault type or a Bearing Fault type is present, the Bearing/Motor Fault is
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triggered.
This is not an actual fault, only an indication that a fault has occurred in the Motor or
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Bearing section. Refer to Table 5-8 M otor/System Status on page 260 and Table 5-5
Bearing Fault Types on page 254.
Review fault log for indication of values out of specified ranges recorded at time of fault.
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Verify the questionable sensor and related connections for failure.
Inverter temperature: The sensor embedded in the Inverter requires a replacement of
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the Inverter if determined faulty.
Cavity Temperature: Refer to Section 4.31.3 C avity Temperature Sensor Verification on
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page 242.
Suction Temperature: Verify suction pressure/temperature sensor. Refer to Section 4.32.3
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Pressure/Temperature Sensor Verification on page 246.
Discharge Temperature: Verify discharge pressure/temperature sensor. Refer to Section
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4.32.3 P ressure/Temperature Sensor Verification on page 246.
Leaving Water Temperature: Verify LEAVE jumper is installed on I/O board.
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Suction Pressure: Review fault log for recorded value.
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Discharge Pressure: Review fault log for recorded value.
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Removed from CC 4.2.X and later software
Indicates the SCR cooling is insufficient.
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If this fault occurs three times within a 30-minute period, a Lock-Out Fault will occur.
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M-SV-001-EN Rev. H-1/23/2023 Page 257 of 294