15
Air Handler Low Voltage Connections
The following composite wiring diagrams detail various configurations in which the air handlers can be used. Examples
include single-stage cooling and heat pump with single or two-stage electric heating. All these configurations can be
applied with convenient connections to outdoor thermostat applications.
The following sections are detailed:
•
Single-Stage Cooling
•
Heat Pump
Each diagram details the connections between room thermostat and the air handlers, and the connections between the
air handlers and the Condensing Unit (or Heat Pump) with optional connections to Outdoor Thermostats. For each
configuration, refer to the explanation of the proper jumper(s) to remove for the corresponding blower speed that will
result in the programmed fixed speed ECM motor.
IMPORTANT: WHEN MATCHING THE ASPT AIR HANDLERS TO A SINGLE SPEED COOLING OR HEAT PUMP
UNIT, REMEMBER TO CONNECT “Y” FROM THE THERMOSTAT TO THE “Y2” ON THE LOW VOLTAGE
TERMINAL BOARD.
An equivalent thermostat can be used in place of the manufacturer’s thermostat part number.
NOTE:
Some models feature low voltage wires and do not include a terminal block. For those applications use the
corresponding colored wires.
NOTES:
1) OUTDOOR THERMOSTAT (OT-1) SHOULD BE THE FIRST
TO CLOSE AND THE LAST TO OPEN.
2) JUMPER W1 AND W2 TOGETHER IF OT-2 IS NOT USED.
3) REMOVE WIRE WHEN USING OUTDOOR THERMOSTAT.
NOMENCLATURE:
OT - OUTDOOR THERMOSTAT (OPTIONAL)
EHR - EMERGENCY HEAT RELAY (OPTIONAL)
COLOR CODES
RD - RED
YL - YELLOW
BL - BLUE
BR - BROWN
OR - ORANGE
WH - WHITE
Wiring is subject to change. Always refer to the wiring diagram on the unit for the most up-to-date wiring.
COOLING UNIT WITH OPTIONAL HEAT KITS OF 10 kW AND BELOW
G
R
C
W1
Y
W
W2
Y2
Y1
O
G
R
TB
YL
BL
TO CONDENSING UNIT
24V CONNECTION
BL
YL
YL
WH
GR
RD
#18 GA. 4 WIRES WITH COOLING
3 WIRES WITHOUT
AIR HANDLER
HIGH VOLTAGE!
DISCONNECT ALL POWER BEFORE SERVICING.
MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO DO SO
MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
WARNING