Table of Contents
Advertisement
11. Electric expansion valve
The electric expansion valve is driven by DC 12V. Power is supplied to 1 or 2 phases of 4-phase winding
G
to switch magnetic pole of winding in order to control opening degree.
Relationship between power switching direction of phase and open/close direction is shown below.
G
When power is supplied, voltages at pins 4 to 1 of CN15~CN18 are about 0.9V; they are about 12V
when no power is supplied. When power is reset, initialization is performed for 10 or 20 seconds.
During initialization, measure all voltages at pins 4 to 1 of CN15~CN18 using mutimeter. If there is any
pin with voltage that has not changed from around 0.9V or 12V, expansion valve or microcomputer is
defective.
Fig. 11-2 shows logic waveform when expansion valve is operating.
G
All manuals and user guides at all-guides.com
Table 11-1
Table 11-2
Pin
Lear
phase No.
wire
1
2
3
4
White
ON
ON
OFF
3
Yellow
OFF
ON
ON
2
Orange
OFF
OFF
OFF
1
OFF
OFF
OFF
Blue
Operation mode
1
2
3
4
5
6
7
8
VALVE CLOSE
8
7
6
5
4
3
2
1
VALVE OPEN
– 71 –
Drive status
4
5
6
7
8
OFF
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
OFF
ON
ON
ON
OFF
OFF
OFF
OFF
ON
ON
ON
MICRO COMPUTER
A
B
A
B
- Quick Links:
- Trouble Shooting
Hide quick links:
Advertisement
Table of Contents
