Lennox LGH094U Unit Information page 80

24 V POWER
TO M3 THERMOSTAT INPUTS
R
TO R
C
2
2 7
G
TO G
K55*1
S86
W1
5
B
W2
TO Y1
A
Y1
ALL OTHER THERMOSTAT
SIGNALS REMAIN CONNECTED
Y2
AS SHOWN ON THE RIGHT.
OCP
TO PROVIDE SUPERMARKET REHEAT SCHEME
USE S86 DEHUMIDISTAT AND K55.
A24
A2
5
Y3
1
J297A
A 7
Y2
2
K27*1
7 1 6
Y1
3
B
2
TO PROVIDE THREE
COMPRESSOR STAGES.
REQUIRES 3 HEAT, 3
A34
COOL THERMOSTAT
AND K27 RELAY.
+ EXC
GND
+SIG
A63
J298A
1
2
B
3
4
9
24 V COMMON
DESCRIPTION
KEY COMPONENT
SENSOR, ELECTRONIC THERMOSTAT
A2
CONTROL, OUTDOOR AIR CFM FLOW
A24
A34 DIFFERENTIAL PRESSURE TRANSDUCER
CONTROL BOARD, MAIN
A55
SENSOR, CO2 (IAQ) OPTIONAL
A63
SENSOR, HUMIDITY
A91
SENSOR ONE, SMOKE, RETURN AIR
A171
SENSOR TWO, SMOKE, SUPPLY AIR
A172
MODULE, CONTROL SMOKE DETECTION
A173
JACK, AIR FLOW CONTROL
J26
JACK, RT16 RETURN AIR SENSOR
J99
JACK, RT6 SUPPLY AIR SENSOR
J100
JACK, SMOKE DETECTOR ONE
J250
JACK, SMOKE DETECTOR ONE
J251
JACK, SMOKE DETECTOR TWO
J252
JACK, SMOKE DETECTOR TWO
J253
JACK, MODULE, CONTROL SMOKE
J255 DETECTION
JACK, SUPPLY SMOKE DETECTOR JUMPER
J261
JACK, ECONOMIZER
J262
JACK, BLOWER DECK
J264
JACK, THERMOSTAT * DDC INTERFACE
J297
JACK, IAQ INTERFACE
J298
JACK, SAFETY INTERFACE
J299
K27, *1 RELAY, TRANSFER
K55,*1 RELAY, BLOWER
K222,
RELAY, COMPRESSOR LOCKOUT
*1
PLUG, AIR FLOW CONTROL
P26
PLUG, RT16 RETURN AIR SENSOR
P99
PLUG, RT6 SUPPLY AIR SENSOR
P100
PLUG, SMOKE DETECTOR ONE
P250
PLUG, SMOKE DETECTOR ONE
P251
PLUG, SMOKE DETECTOR TWO
P252
1- The A55 Unit Controller energizes the thermostat components with 24VAC via J/P297-1.
2- The A55 Unit Controller proves the optional N.O. filter switch S27 (indicates dirty filter when closed) and optional
N.O. air flow switch S52 (indicates no air [i.e. broken belt] system shuts down).
3- The A55 Unit Controller receives data from the supply and return smoke detectors A171 and A172, blower motor
overload relay S42, discharge sensor RT6 and return air sensor RT16.
4- The A55 Unit Controller receives data from the electronic thermostat A2 (Y1, Y2, W1, W2, G, OCP)
and the CO sensor A63 (if economizer is used). A55 energizes the appropriate components.
2
ELECTRONIC OR ELECTROMECHANICAL THERMOSTAT
2
J297A P297
1
R
C 2
B
3
G
A24
J298A
4
W1
1 1
5
W2
2 2
B
6
Y1
3 3
9 7
Y2
10
8
OCP
C
9
10
J298A J298A
P298
1
1
2
2
B
B
3
3
9
4
C
VO 5
6
A91
J298A
7
D
1
VIN
8
2
9
B
GND
3
10
9
J299A P299
1
2
3
1
S135 S42
B
4
5
K222*1
C
6
7
S149 S179 D
6
8
8
9
10
PLUG, SMOKE DETECTOR TWO
P253
PLUG, MODULE, CONTROL SMOKE
P255 DETECTION
PLUG, ECONOMIZER
P262
PLUG, BLOWER DECK
P264
P297 PLUG, THERMOSTAT * DDC INTERFACE
PLUG, IAQ INTERFACE
P298
PLUG, SAFETY INTERFACE
P299
PLUG, SYS BUS
P304
SENSOR, SUPPLY AIR TEMP
RT6
SENSOR, RETURN AIR TEMP
RT16
SWITCH, FILTER
S27
SWITCH, AIRFLOW
S52
S42 SWITCH, OVERLOAD RELAY BLOWER MOTOR
SWITCH, DEHUMIDISTAT
S86
OVERLOAD, BLOWER MOTOR SUPPLY
S135
SWITCH, OVERFLOW ONE
S149
SWITCH, OVERFLOW TWO
S179
TRANSFORMER, 120 V GENERATOR POWERED
T8
A55
10
11
W1
W2
12
R
C
1
AI*1
2
HUM
3
4
TMP
4
DO*1
J100 P100
C
5 1
RT16
DO*2
6 4
RT6
DI*1
3
R
J99 P99
1 1
C
2 4
DI*2
R
J264C
DI*3 6 S52
6
R
7
DI*4
C
8
S27
P304
FOR MOTORS WITH S42 EXTERNAL OVERLOAD LESS
1
INVERTER, SEE INVERTER WITH BY PASS FOR S42 HOOK UP
USE S86 DEHUMIDISTAT AND K55 FOR OPTIONAL
2
SUPERMARKET REHEAT SCHEME, PRODIGY PARAMETERS NEED
TO BE MODIFIED UNDER THE SETTINGS MENU OR VIA UC
SOFTWARE FOR SIMULTANEOUS HEATING AND COOLING.
3 REMOTE LOCATION OF RT6
P298-8 (DO-1) IS SERVICE RELAY OUTPUT (24VAC)
4
IF USED CONNECT TO AN INDICATOR LIGHT
THERMOSTAT HOOKUP FOR PROGRAMMABLE CONFIGURATION
5
OF THE BOARD (A55).
PRODIGY SETTINGS MUST BE MODIFIED WHEN K222, S42,
6
S52, S149 OR S179 ARE INSTALLED
CONNECT A172 SENSOR TO J261 ON SUPPLY AIR SMOKE
7
DETECTOR ONLY
8
S179, OVERFLOW SWITCH USED ON LGH/LCH 420-600 UNITS
ONLY
9
A63, A34 & A24 ARE MUTUALLY EXCLUSIVE
10
FACTORY INSTALLED OPTION FOR LGH/LCH 242-600 UNITS
ONLY
Page 80
J255
1 6 3 4
P255
2
7
M3
J299A
DI1
1
2
R
RT6
T8
A
B
TO PROVIDE COMPRESSOR
SHUT OFF, 120 VAC
PROVIDED BY GENERATOR
ACCESSORIES
REV. 3