Hvac Wiring Diagrams; Conventional Heat/Cool Single Transformer - Aprilaire 8840 Safety & Installation Instructions

HVAC WIRING DIAGRAMS

CONVENTIONAL HEAT/COOL SINGLE TRANSFORMER (USE JUMPER)
THERMOSTAT
CONVENTIONAL HEAT/COOL TWO TRANSFORMER (REMOVE JUMPER)
THERMOSTAT
1 R and C can be
powered from the
HVAC equipment
transformer or any
other constantly
powered 24VAC
source.
8
C
TRANSFORMER
R
1
RC
2
RH
3
HC HP
W W 1 HEATING
st
W2 W2 2 HEATING
nd
W3 B 3 HEATING
rd
Y Y 1 COOLING
st
Y2 Y2 2 COOLING
nd
Y3 O
3 COOLING
nd
G G FAN
L
C
EQ
1
TRANSFORMER
C
R
1
COOLING TRANSFORMER
RC
2
RH
3
HEATING TRANSFORMER
HC HP
W W 1 HEATING
st
W2 W2 2 HEATING
nd
3 HEATING
W3 B
rd
Y Y
1 COOLING
st
Y2 Y2
2 COOLING
nd
Y3 O
3 COOLING
rd
G G FAN
L
C
EQ
HVAC WIRING DIAGRAMS
HEAT PUMP SINGLE TRANSFORMER (USE JUMPER WIRE)
1
THERMOSTAT
2
3
HEAT PUMP TWO TRANSFORMER (REMOVE JUMPER WIRE)
1
THERMOSTAT
2
3
1
R and C can be
powered from the
HVAC equipment
transformer or any
other constantly
powered 24VAC
source.
C
R
HEAT PUMP TRANSFORMER
RC
RH
HC HP
W W 1 HEATING
st
W2 W2 2 HEATING
nd
W3 B REVERSING VALVE
Y Y 1 COMPRESSOR
st
Y2 Y2
2 COMPRESSOR
nd
Y3 O REVERSING VALVE
G G FAN
L FAULT DETECT
C
EQ
1
TRANSFORMER
C
R
HEAT PUMP TRANSFORMER
RC
RH
HEATING TRANSFORMER
HC HP
W W 1 HEATING
st
W2 W2 2 HEATING
nd
W3 B REVERSING VALVE
Y Y 1 COMPRESSOR
st
Y2 Y2 2 COMPRESSOR
nd
Y3 O REVERSING VALVE
G G FAN
L FAULT DETECT
C
EQ
9