d. Printed circuit board (PCB) of CH unit
By the LED on the PCB in the CH unit, the condition of the expansion valve and alarm information can be checked.
LED4
PCB - CH Unit
LED5
LED6
LED7
1) The table below indicates the LED condition for each expansion valve when performing normal operation.
Part name
Expansion valve
Contents of functions
LED4 (Green)
MVD2
Fully opened (480 pulse): Turn ON
Fully closed (0 pulse): Turn OFF
LED5 (Green)
MVD1
Fully opened (600 pulse): Turn ON
Fully closed (0 pulse): Turn OFF
LED6 (Green)
MVS2
Fully opened (480 pulse): Turn ON
Fully closed (0 pulse): Turn OFF
LED7 (Green)
MVS1
Fully opened (600 pulse): Turn ON
Fully closed (0 pulse): Turn OFF
2) When alarming, the alarm code is indicated by LED.
LED
Alarm code
Contents
4
5
6
7
O
O
X
X
03
Abnormal transmission between CH unit and outdoor unit.
X
X
O
O
03
Abnormal transmission between CH unit and indoor unit.
O
O
O
O
C1
2 or more CH units are connected between outdoor unit and indoor unit.
O
O
O
X
C2
9 or more indoor units connected to CH unit.
X
O
O
X
C3
The indoor units of different refrigerant cycle is connected to CH unit.
O: Flashing (Turn ON; 0.5 sec. / Turn OFF; 0.5 sec.)
X: Turn OFF.
8 Troubleshooting
261
SMGB0065 rev. 1 - 12/2010
8