Gree GUHD18ND3FO - Page 114

U-Match Series DC Inverter Service Manual
111
7
COMM1
Communication line [1-3.3V
、
2-TX
、
3-RX
、
4-GND]
Communication needle stand of
main control drive
1-pin: +3.3V
2-pin: TXD
3-pin: RXD
4-pin: GND
8
CN2
Communication line with1-pin
GND, 2-pin B and 3-pinA
）
Communication needle stand with
indoor unit
1-pin: GND
2-pin: B
3-pin: A
9
CN1
Communication line with 1-pin plus
12V, 2-pin B, 3-pin A and 4-pin
GND
Communication interface
(reserved):
1-pin: +12V
2-pin: B
3-pin: A
4-pin: GND
10
H-PRESS
High pressure switch for fan speed
adjustment
Pressure protection switch for fan
speed adjustment
11
HPP
High pressure switch for system
protection (obligate
）
Interface of high pressure
protection
12
LPP
Low pressure switch for system
protection (obligate
）
Interface of low pressure
protection
13
OVC-COMP
Compressor overload protection
Interface of compressor overload
protection
14
T-SENSOR2
1&2 pin: Tube sensor
3&4 pin: Ambient temperature
5&6 pin: Air discharge
1&2 pin: Case temperature sensor
3&4 pin: Ambient temperature
sensor
5&6 pin: Discharge temperature
sensor
15
FA
Electronic expansion valve line
1 to 4-pin: Drive impulse
output;5-pin: +12V;
Interface of electronic expansion
valve:
1 to 4-pin: Drive impulse output;
5-pin: +12V;
16
HEAT
Compressor electrical heater
Compressor electric heating belt
17
VA-1
Chassis electrical heater
Chassis electric heating belt
18
4V
4-way valve
4-way valve