Page 12
LGM/LCM156, 180, 210, 240, 300
FIGURE 11
FIELD WIRING REHEAT UNITS (Using A Humidity
Sensor With Less Than 150 Ft. Wire Runs)
9
8
J298
P298
1
2
3
4
5
6
7
10
A91
VIN
VO
GND
R
C
AI-1
HUM
TMP
AI2
C
R
UNUSED
WIRE
NOT
CONNECTED
NOT
CONNECTED
DRAIN
A55 UNIT
CONTROLLER
FIGURE 12
FIELD WIRING REHEAT UNITS (Using A Humid
ity Sensor With More than 150 Ft. Wire Runs)
ISOLATED 24V
TRANSFORMER
9
8
J298
P298
1
2
3
4
5
6
7
10
A91
VIN
VO
GND
R
C
AI-1
HUM
TMP
AI2
C
R
NOT
CONNECTED
NOT
CONNECTED
DRAIN
A55 UNIT
CONTROLLER
FIGURE 13
FIELD WIRING REHEAT UNITS
(Using A Dehumidification Switch)
7
10
8
9
R
DI
−
4
C
Use 24 VAC (R) from any terminal
available on P299
−
2,
−
5, or
−
7.
P299
DEHUMIDIFICATION
SWITCH
Blower Operation and Adjustments
Supply Air Staged Units -
The blower rotation will
always be correct on units equipped with an inverter.
Checking blower rotation is not a valid method of
determining voltage phasing for incoming power.
Supply Air Staged Units and Units Equipped With
Optional Voltage or Phase Detection
- The Unit
Controller checks the incoming power during start-up. If
the voltage or phase is incorrect, the Unit Controller will
display an alarm and the unit will not start.
A-Blower Operation
Refer to the Unit Controller Setup Guide to energize
blower. Use this mobile service app menu:
SERVICE > TEST > BLOWER
Instructions provided with the thermostat may also be
used to initiate blower only (G) demand. Unit will cycle on
thermostat demand. The following steps apply to
applications using a typical electro-mechanical
thermostat.
1- Blower operation is manually set at the thermostat
subbase fan switch. With fan switch in
ON
position,
blowers will operate continuously.
2- With fan switch in
AUTO
position, the blowers will
cycle with demand. Blowers and entire unit will be off
when system switch is in
OFF
position.
IMPORTANT
Three Phase Scroll Compressor Voltage Phas
ing
Three phase scroll compressors must be phased se
quentially to ensure correct compressor and blower*
rotation and operation. Compressor and blower are
wired in phase at the factory. Power wires are color-
coded as follows: line 1-red, line 2-yellow, line 3-blue.
1-Observe suction and discharge pressures and blow
er* rotation on unit start-up.
2-Suction pressure must drop, discharge pressure must
rise and blower* rotation must match rotation marking.
If pressure differential is not observed or blower* rota
tion is not correct:
3-Disconnect all remote electrical power supplies.
4-Reverse any two field-installed wires connected to
the line side of S48 disconnect or TB13 terminal strip.
Do not reverse wires at blower contactor.
5-Make sure the connections are tight.
Discharge and suction pressures should operate at
their normal start‐up ranges.
*Supply air inverter blower motors should rotate in the
correct direction; verify scroll compressor rotation
separately. Contact technical support if the blower is
rotating incorrectly.
