5
- 15
1
2
3
4
5
6
7
8
9
2WAY VRF SYSTEM
Trouble Diagnosis
3. 2WAY Alarm Codes
F17 Alarm
Alarm code
F17
Alarm meaning
Low pressure sensor of the outdoor unit has failure. (LPS)
Alarm conditions
(1) Sensor short circuit
(2) Sensor open circuit
Probable cause
(1) Sensor malfunction (including connector)
(2) The Outdoor Unit Control PCB malfunction
Check
(1) Measure the sensor resistance. Check that the sensor is operating normally.
(2) Use a remote monitor or a PC monitor to check the temperature that is recognized by the
microcomputer.
Correction
—
Example
—
Notes
—
F31 Alarm
Alarm code
F31
Alarm meaning
EEPROM on outdoor unit PCB has failure.
Alarm conditions
(1) Non-volatile memory is not present when power initialization occurs.
(2) Read values do not match after writing to non-volatile memory is complete.
Probable cause
(1) Memory was not inserted after the Outdoor Unit Control PCB was replaced.
(2) The lifetime of the non-volatile memory has been reached.
(3) Non-volatile memory is installed incorrectly (wrong direction, bent pins, etc.).
Check
(1) Check the non-volatile memory on the Outdoor Unit Control PCB.
Correction
—
Example
—
Notes
—
H01, H11 Alarm
Alarm code
H01, H11
Alarm meaning
H01 : Overcurrent in 1st compressor.
H11 : Overcurrent in 2nd compressor.
Alarm conditions
1st compressor, 2nd compressor primary current detected overcurrent higher than the values
(overcurrent) listed in the table below.
Model name
U-72ME2U9
U-96ME2U9 U-120ME2U9 U-144ME2U9
Current (A)
30.0
43.0
30.0
30.0
Model name
U-72ME2U94 U-96ME2U94 U-120ME2U94 U-144ME2U94
Current (A)
19.5
19.5
19.5
19.5
Probable cause
(1) Wiring failure
(2) Operating under extremely high-pressure status (over-loaded operation)
(3) Power source and voltage failure (sudden voltage decrease)
Check
(1) Wiring failure
Check whether the connection between “HIC PCB” and “inverter compressor” is wiring failure.
(2) Operating under extremely high-pressure status (over-loaded operation)
•
Failure to open the service valve of the outdoor unit
Check open/closed status of the service valve of the outdoor unit.
•
Connect a gauge to the high-pressure outlet and check for changes in the value displayed
by the monitoring software, and for large deviation of the gauge pressure.
(3) Check power source and voltage.
Correction
(1) Wiring failure
Correct wiring disconnection and wiring failure.
(2) Operating under extremely high-pressure status (over-loaded operation)
•
Open the service valve of the outdoor unit.
•
Replacing high-pressure sensor
When replacing a high-pressure sensor, carry out after refrigerant recovering of the outdoor unit.
(3) Improving power source and voltage
Example
—
Notes
—
SM830237-07_北米向け2WAY_VRF.indb 15
18/06/18 18:50:11