Outdoor Unit Operation Monitor Function; Digital Indicator Led3 Working Details; Display During Error Postponement; When The Display Blinks - Mitsubishi Electric MXZ-8A140VA Technical & Service Manual

<Outdoor unit operation monitor function>
Digital indicator LED3 displays 2 digit number or code to inform operation condition and the meaning of error code by
controlling DIP SW2 on outdoor controller.
Operation indicator SW2 : Indicator change of self diagnosis
SW2 setting
ON
1 2 3 4 5 6
<Digital indicator LED3 working details>
(Be sure that 1 to 6 in the SW2 are set to OFF.)
(1) Display when the power supply is ON.
When the power supply is ON, blinking displays by turns.
Wait for 4 minutes at the longest.
(2) When the display lights (Normal operation)
1Operation mode display
LED3
The tens digit : Operation mode
Display Operation Model
O OFF / FAN
C COOLING / DRY
H HEATING
d DEFROSTING

2Display during error postponement

Postponement code is displayed when
compressor stops due to the work of
protection device.
Postponement code is displayed while
error is being postponed.

(3) When the display blinks

Inspection code is displayed when compressor stops due to the work of protection devices.
Display Inspection unit
0 Outdoor unit,
Branch box unit
1 Indoor unit
Display Contents to be inspected (When power is turned on)
F3 63L connector(red) is open.
F5 63H connector(yellow) is open.
2 connectors (63H/63L) are open.
F9
Branch box/outdoor communication error (Signal receiving error) (Outdoor unit)
E8
Indoor/branch box communication error (Signal receiving error) (Branch box)
Branch box/outdoor communication error (Transmitting error) (Outdoor unit)
E9
Indoor/branch box communication error (Transmitting error) (Branch box)
• Miswiring of indoor - branch box/branch box - outdoor unit connecting wire
EA
• Too many indoor units/branch box are in the system.
Miswiring of indoor - branch box/branch box - outdoor unit connecting wire(converse wiring or disconnection)
Eb
Startup time over
Ec
Communication error except for outdoor unit
E0~E7
Display detail
(Lighting)
The ones digit : Relay output
Display
0
1
2
3
4
5
6
7
8
A
Display Contents to be inspected (During operation)
U2 Discharge temperature fault
Low-discharge superheating fault, Erroneous connection of refrigerant pipes or the
U7
connecting wires
High pressure fault (63H operates)
U1
UL Low pressure fault (63L operates)
U6 Abnormality of power modules
Compressor overcurrent shutoff (Start up locked)
UF
Current sensor fault (P. B.)
UH
UP Compressor overcurrent shutoff fault
U3 Discharge pipe/compressor thermistor (TH4) open or short-circuit
Outdoor unit thermistors (TH3, TH6, TH7, and H8), 63HS, and branch box thermistors
U4
open or short-circuit
U5 HEATSINK temperature fault
U8 Abnormality in outdoor fan motor
Voltage fault, current sensor fault (N. F.)
U9
Forced compressor stop
PA (Overlap malfunction of drain pump in indoor unit and linear expansion valve in branch box.)
73
Explanation for display
1 second
interval
ON
1
Warming-up
Compressor
Compressor
— —
— —
— —
— —
— ON
— ON
— ON
— ON
ON —
ON —
SW2
(Initial setting)
2 3 4 5 6
Solenoid valve
4-way valve
(SV1, 2)
— —
— ON
ON —
ON ON
— —
— ON
ON —
ON ON
— —
ON —
Unit