Mitsubishi Electric PRH-P8MYA Technical & Service Manual page 49

<Outdoor-side unit operation monitoring function>
The operation status and check code contents can be ascertained by means of the 2-digit number and symbol on digital
display light emitting diode LED2 by operating DIP switch SW2.
<Description of operation of digital display light emitting diode (LED2)>
• When ON (normal operation): Displays the operation mode.
[Tens digit: Operation mode]
Display Operation mode
O stopped
C Cooling/Dry
H Heating
d Defrost
• When blinking (Operation stopped by tripping protection device): Displays the check mode
Display Check unit
0 Outdoor-side unit
1 Indoor-side unit
• PRH-P8MYA/P10MYA/P16MYA/P20MYA
Display
U2 Compressor discharge temperature abnormal, CN23 short-circuit connector unplugged
U3 Compressor discharge temp thermistor (TH2) open/short
U4 Liquid temp thermistor (TH1), Condenser/evaporater temp thermistor (TH3) open/short
U6 Compressor overcurrent protection trip (51C trip)
UE High pressure protection (63H1 trip)
UL Low pressure protection (63L trip)
P1-P9 Indoor-side unit abnormal
A0-A8 M-NET communication abnormal
ON
LED2
[Units digit: Relay output]
Display
0
1
2
3
4
5
6
7
Display
Indoor-side/outdoor-side communication receive abnormal
E8
(outdoor-side unit)
Indoor-side/outdoor-side communication send abnormal
E9
(outdoor-side unit)
Indoor-side/outdoor-side connection erroneous wiring
EA
Indoor-side/outdoor-side connection erroneous wiring
Eb
(indoor-side unit power failure, disconnection)
Ed Serial communication abnormal (M-NET)
E0-E7 Communication other than outdoor-side unit abnormal
F8 Input circuit faulty
Check contents (operating)
- 46 -
SW2
1 2 3 4 5 6
ON
OFF
(Load status)
Compressor 4-way valve
– –
– –
– ON
– ON
ON –
ON –
ON ON
ON ON
Check contents (at power on)
Bypass solenoid valve
–
ON
–
ON
–
ON
–
ON