Carrier 40MBDAQ - Page 36

40MBDAQ: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
36
DIAGNOSIS AND SOLUTION (CONT.)
J0 (Evaporator high temperature protection)
Description: When the evaporator coil temperature is more than 140°F(60°C), the unit stops. It starts again only when the
evaporator coil temperature is less than a certain value.
Recommended parts to prepare:
• Evaporator coil temperature sensor
•Fan
•PCB
Troubleshooting
Evaporator high temperature protection.
Is the compressor operating?
Check the outdoor ambient temperature.
YES
Is it higher
than 86°F (30°C)?
Stop the unit.YES
Check if the air-outlet is blocked.
NO
Is it blocked? Clean the air-outlet.
YES
Check the indoor fan.
NO
Is it running normally?
Refer to the
Fan Speed Is Out of Control
malfunction.
Identify the cause and solve.
NO
Check the heat
exchanger and
lter.
YES
Are they
dirty?
Clean the heat
exchanger and lter .
YES
Replace the indoor main PCB.
NO
Check the connection
between T2 and the PCB.
NO
Is it in working order?
Check the resistance of T2
according to Appendix 1.
YES
Is it normal?
YES
Correct the
connection.
NO
Replace the
temperature sensor.
NO