Honeywell PC8900A Manual page 8

W8900B Terminal
Designations
1 PC8900A Control Panel
2 PC8900A Control Panel
3 PC8900A Control Panel
4 PC8900A Control Panel
AUX a Stage-3 heat control (strip heat)
B Heating, changeover valve
C 24 Vac transformer common
CO Carbon dioxide monitor
2
E Emergency heat relay
VNT VNT relay
G Fan relay
GND Ground
L System monitor
O Cooling, changeover valve
R 24 Vac system transformer
S, S1 Remote Air Temperature Sensor
T, T1 Discharge Air Temperature Sensor
Stage-2 heat control (compressor)
W2 b
c Compressor contactor
Y1/W1
Compressor contactor
Y1/W1 c
Stage-1 cool control
Y1/W1 c
Y1/W1 c Stage-1 heat control
Y2 Stage-2 cool control
None Clogged filter switch or common connection
None Defrost
None HSII Control Panel
None LEDs
None LO and HI speed fan relays
None Momentary circuit, changeover
None Outdoor thermistor
d External temperature readout, T relay
Out
a AUX controls the auxiliary heat like W2, and allows additional stages of auxiliary heat with outdoor thermostats while
maintaining the proper second stage anticipation.
b
For systems without 2nd stage heat, configure W2 to No.
c
For systems requiring separate W1 and Y1 terminals for proper heat pump operation, refer to Fig. 18 and 19.
d
Replace existing sensor with C7089A Outdoor Sensor.
68-0173—3
Table 3. Heat Pump Applications (W8900B).
Function
8
Existing Thermostat
Designations
(Standard)
—
—
—
—
W3
B
C
—
E
—
G
—
L
O
R
—
—
W2
—
Y
Y1
W1
Y2
X
—
—
—
—
—
T
—
Existing Thermostat
Designations
(Customer Specials)
—
—
—
—
—
—
X,B
—
K
—
F
—
L
R
V
—
—
H2,Y,R4
RS
M
C1,M
H1,R3
C2
X1,X2,C
P
L,C,H
A,A1,A2,Z,C,L
R1,R2
O
A
—