Installation manual
19
18
Dry contact for thermostat
ENGLISH
Setting and using method
Setting and using method
Thermostat
LG does not supply this section
(Field supply)
LOW
MIDDLE
HIGH
L
L
N
L L
Operation
Thermal
FA
N
COOL
COMM
C
AC 24 V
R Y G O
n
For heat pump thermostat with O terminal signal input
Thermostat Fan & System Switch
Input
IDU Response
[Mode / Thermal / Fan]
FAN
[Auto / On]
MODE
[Cool / Heat / Off]
Operation
Thermal
[Y]
FAN
[G]
COOL
[O]
-
-
-
0
-
-
-
Disable Operation
Auto
OFF
-
1
0
0
0
Off
Cool
RT > SP
1
1
0
1
Cool / On / On
RT < SP
1
0
0
1
Off
Heat
RT < SP
1
1
0
0
Heat/ On/On
RT > SP
1
0
0
0
Off
ON
FAN
-
1
0
1
0
Fan/ Off/ On
Cool
RT > SP
1
1
1
1
Cool/ On/ On
RT < SP
1
0
1
1
Fan/ Off/ On
Heat
RT < SP
1
1
1
0
Heat/ On/ On
RT > SP
1
0
1
0
Fan/ Off/ On
Notes
• Thermostats that close contacts "O" or "B" during Cool or Heat call only have not been verified. "O"
and/or "B" contact closure must be maintained during respective cycle / mode selection.
• IDU Fan logic, depending on model selected, may delay IDU fan operation momentarily during a cold
start heat call. This function allows IDU coil to warm up prior to operating fan in some IDU models.
• Thermostats that use resistive anticipation are not supported at this time.
• Verify documentation of desired thermostat so that the logic is same as shown in the table above.
※
RT : Room Temperature
※
SP : Set Point
Thermostat
LG does not supply this section
(Field supply)
LOW
MIDDLE
HIGH
L L L
Operation
Thermal
FA
N
HEA
T
COMM
L
N
C
AC 24 V
R Y G B
n
For heat pump thermostat with B terminal signal input
Thermostat Fan & System Switch
Input
IDU Response
[Mode / Thermal / Fan]
FAN
[Auto / On]
MODE
[Cool / Heat / Off]
Operation
Thermal
[Y]
FAN
[G]
HEAT
[B]
-
-
-
0
-
-
-
Disable Operation
Auto
OFF
-
1
0
0
0
Off
Cool
RT > SP
1
1
0
0
Cool / On / On
RT < SP
1
0
0
0
Off
Heat
RT < SP
1
1
0
1
Heat/ On/On
RT > SP
1
0
0
1
Off
ON
OFF
-
1
0
1
0
Fan/ Off/ On
Cool
RT > SP
1
1
1
0
Cool/ On/ On
RT < SP
1
0
1
0
Fan/ Off/ On
Heat
RT < SP
1
1
1
1
Heat/ On/ On
RT > SP
1
0
1
1
Fan/ Off/ On
Notes
• Thermostats that close contacts "O" or "B" during Cool or Heat call only have not been verified. "O"
and/or "B" contact closure must be maintained during respective cycle / mode selection.
• IDU Fan logic, depending on model selected, may delay IDU fan operation momentarily during a cold
start heat call. This function allows IDU coil to warm up prior to operating fan in some IDU models.
• Thermostats that use resistive anticipation are not supported at this time.
• Verify documentation of desired thermostat so that the logic is same as shown in the table above.
※
RT : Room Temperature
※
SP : Set Point
