Troubleshooting Using The 7 Segment Display; Simple Checking By 7-Segment Display; Checking Method By 7-Segment Display; Check Mode Items - Hitachi RAS-(3-6)HVNC1(E) Service Manual

8 Troubleshooting
8.3.3 Troubleshooting using the 7 segment display

Simple checking by 7-segment display
Turn ON indoor unit connected to
1
the outdoor unit
2 Turn ON the outdoor unit
3 Auto-addressing starts
Outdoor unit, circuit board, PCB1

Checking method by 7-segment display
Operating conditions and each part of refrigeration cycle can be checked by 7-segment and push switches (PSW) on the
PCB in the outdoor unit. During checking data, do not touch the electric parts except for the indicated switches because
220-240V is applied to them. Pay attention not to contact the tools with electrical parts. If contacted, electrical parts will be
damaged.
Y52C
8
8
Y20F
Y20A
Manual
8 8
defrost
. .
SEG1 PSW1 PSW2 PSW3
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Check mode items
N O T E
For figures consisting of more than 2 digits, the upper 2 digits and lower 2 digits of the figures are indicated alternatively
every 0.5 sec In the 7-segments display, as shown below (the lower 2 digits are shown together with a dot at the lower
right corner)
Example: 1253
292
SMGB0087 rev.0 - 12/2013
During auto-addressing, the following items can be checked using the
outdoor unit's on-board 7-segment LED display:
1 Disconnection of power supply to the indoor unit.
2 Reverse connection of the operating line between the outdoor and
indoor units.
3 Duplication of indoor unit number.
•
Y21
•
FAN1
•
YCH
•
FAN2
PSH
12 53
To start checking, press PSW2 switch for more than three sec-
onds.
To proceed checking, press the PSW2 switch.
To back to the previous item, press the PSW3 switch.
To cancel this checking, press the PSW2 switch for more than
3 seconds.