28
No.
Symptom
LED indication
Abnormal point/
Condition
Condition
Remedy
20
Outdoor unit
operates.
7-time f ash
2.5 seconds OFF
Low discharge tem-
perature protection
Temperature of discharge temperature thermistor has been
50°C or less for 20 minutes.
• Refer to 11-5. "Check of LEV".
• Check refrigerant circuit and refrig-
erant amount.
21
8-time f ash
2.5 seconds OFF
PAM protection
PAM: Pulse Ampli-
tude Modulation
The overcurrent f ows into IC821 (Switching power transistor)
or the bus-bar voltage reaches 320 V or more, PAM stops and
restarts.
This is not malfunction. PAM pro-
tection will be activated in the fol-
lowing cases:
1 Instantaneous power voltage
drop. (Short time power failure)
2 When the power supply voltage
is high.
22
9-time f ash
2.5 seconds OFF
Inverter check mode The connector of compressor is disconnected, inverter check
mode starts.
• Check if the connector of the com-
pressor is correctly connected.
Refer to 11-5. "How to check
inverter/compressor".
NOTE:
1. The location of LED is illustrated at the right f gure. Refer to 11-6.1.
2. LED is lighted during normal operation.
The f ashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the f ashing frequency is “2”.
ON
OFF
2.5-second OFF
2.5-second OFF
0.5-second ON
0.5-second ON
LED
←
Flashing
Inverter P.C. board
OBH751
