Error Code [1302] (At Startup); Error Code [1500] - Mitsubishi Electric R410A Service Handbook

[7-3 Error Code Definitions and Solutions: Codes [1000 - 1999] ]
7-3-4

Error Code [1302] (at startup)

1. Error code definition
High pressure fault 2 (Outdoor unit)
2. Error definition and error detection method
If the pressure of 0.098MPa [14psi] or lower is registered on the pressure sensor immediately before start-up, it will trigger an
abnormal stop, and error code "1302" will be displayed.
3. Cause, check method and remedy
(1) Inner pressure drop due to a leakage.
(2) Pressure sensor failure
(3) Shorted-circuited pressure sensor cable due to torn
outer rubber
(4) A pin on the male connector on the pressure sensor
is missing or contact failure
(5) Disconnected pressure sensor cable
(6) Failure of the pressure sensor input circuit on the
controller board
7-3-5

Error Code [1500]

1. Error code definition
Refrigerant overcharge
2. Error definition and error detection method
An error can be detected by the discharge temperature superheat (TdSH).
1) If the formula "TdSH 10°C [18°F]" is satisfied during operation (first detection), the outdoor unit stops, goes into the 3-minute
restart mode, and starts up in three minutes.
2) If a TdSH of 10°C [18°F] or below is detected again (second detection) within 30 minutes of the first stoppage of the outdoor
unit as described above, the outdoor unit stops again, goes into the 3-minute restart mode, and restarts after three minutes.
3) If a TdSH of 10°C [18°F] or below is detected (sixth detection) within 30 minutes of the fifth stoppage of the outdoor unit as
described above, the unit comes to an abnormal stop, and "1500" appears on the display.
4) If a TdSH of 10°C [18°F] or below is detected after 30 minutes have elapsed after a stoppage of the outdoor unit, the unit will
follow the same sequence as the first detection of the condition as described in section 1) above.
5) The period of 30 minutes after a stoppage of the outdoor unit is regarded as a preliminary error, and a preliminary error code
appears on the LED display.
3. Cause, check method and remedy
(1) Overcharged refrigerant
(2) Thermistor input circuit failure on the control board
(3) Faulty mounting of thermistor (TH4)
(4) Outdoor unit LEV2a, b actuation failure
HWE14080
Cause
Cause
Heating
Check method and remedy
Refer to the following page(s). [8-5-1 Comparing the
High-Pressure Sensor Measurement and Gauge
Pressure](page 253)
Check method and remedy
Refer to the following page(s). [6-9 Evaluating and Adjust-
ing Refrigerant Charge](page 127)
Check the temperature and pressure readings on the sen-
sor that are displayed on the LED monitor.
Check the temperature and pressure readings on the
thermistor that are displayed on the LED monitor.
Refer to the following page(s). [8-8 Troubleshooting LEV
Problems](page 258)
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