E4: T3/T4 Temperature Sensor Error - Midea VRF Series Service Manual

2.4 E4: T3/T4 Temperature sensor error

Digital display output
Description
 Heat exchanger deicer temperature sensor (T3) error or outdoor air temperature sensor (T4) error.
 All units stop running.
 Error code is displayed on the unit with the error.
Trigger / recover condition
 Trigger condition: The main control board cannot receive the feedback signal of temperature sensor T3 or T4.
 Recover condition: The main control board can receive the feedback signal of temperature sensor T3 or T4.
 Reset method: Resume automatically.
Possible causes
 Temperature sensor not connected properly or has malfunction.
 Outdoor main PCB damaged.
Procedure
Temperature sensor connection on
outdoor main PCB is loose
Temperature sensor has short-circuited
Replace the outdoor main PCB
Notes:
1. Outdoor air temperature sensor (T4) and heat exchanger deicer temperature sensor (T3) connection is port CN1 on the outdoor main PCB.
2. Measure sensor resistance. If the resistance is too low, the sensor has short-circuited. If the resistance is not consistent with the sensor's resistance
characteristics table, the sensor has failed. Refer to Table 6-4.1 in Part 6, 4.1 "Temperature Sensor Resistance Characteristics".
E4
1
No
2
or failed
No
Yes
Ensure the sensor is connected properly
Yes
Replace the sensor
V6R VRF 50/60Hz
91