Thermo King 098203, Maintenance Manual

Page: 254 / 264

Diagnosis: Troubleshooting, Warnings and Alarm Codes
252
137 Sensor System Overload
• The controller sensor measurement is overloaded.
• This situation will probably introduce wrong
readings at other sensors than the one introducing
the overload.
• Indicates:
• Not intended voltage is introduced at one of the
sensor inputs.
• Transducer, connection or cabling with voltage
supply for the sensor might short circuit this
voltage supply onto the measuring input.
• Sensor input which might initiate the problem:
• At connector J3:
• Humidity sensor (4-20mA type) pin 15-16.
• At connector J1:
• AVL position pin 1-3.
• Discharge pressure pin 4-6.
• Suction pressure pin 7-9.
• At least one of the sensors circuits holds a
short between sensor voltage and sensor
signal.
• Problem might be located any were from the
connection to the sensor itself.
• Action:
• Disconnect sensors and look for a non
intended short between sensor voltage and
the sensor line.
• The sensor with the problem might show up
with its own alarm.
138 AVL Sensor Error
• Occurs if the sensor is detected to be out of range,
open or short circuit.
• Indicates:
• Sensor failure.
• Using DATA menu evaluate sensor readings.
• Check wiring to be correct and connected.
• Check J1 plug is plugged and connected to
controller.
• Check voltage at J1 pin 1 to be 0.5 – 4.5 VDC.
• Check supply voltage at J1 pin 3 (GND) to pin
2 to be approximately 12.6VDC.
• Replace sensor.
139 Internal File Handling Error
• Occurs if the read or write process of nonvolatile
information (i.e. Configuration and settings) fails.
• Indicates:
• Internal file read or write failure.
• Replace controller.
140 Evaporator Section Too Hot
• Occurs if supply air, return air or evaporator coil
temperature reads temperature at or above 60C.
• Indicates:
• Failing heater circuit, hanging output.
• Failing evaporator fan.
• Observe temperature readings to locate the
problem.
• Use manual function test to determine the
failing component.
• Use the tester to determine the problem.
Alarm Codes, Descriptions and Corrective Actions (Continued)
Code Description Corrective Action