Step 9 - Sequence Of Operation - Carrier FZ4A Installation Instructions Manual

Step 9 — Sequence of Operation
A. Continuous Fan
Thermostat closes R to G. G energizes fan relay on PCB which
completes circuit to indoor blower motor. When G is de- energized,
there is a 90- sec delay before relay opens.
B. Cooling Mode
Thermostat energizes R to G, R to Y, and R to O (heat pump only).
G energizes fan relay on PCB which completes circuit to indoor
blower motor. When G is de- energized, there is a 90- sec delay
before fan relay opens.
C. Heat Pump Heating with Auxiliary Electric Heat
Thermostat energizes R to G, R to Y, and R to W. G energizes fan
relay on PCB which completes circuit to indoor blower motor. W
energizes electric heat relay(s) which completes circuit to heater
element(s). When W is de- energized, electric heat relay(s) open,
turning off heater elements. When G is de- energized there is a
90- sec delay before fan relay opens.
D. Electric Heat or Emergency Heat Mode
Thermostat closes R to W. W energizes electric heat relay(s) which
completes circuit to heater element(s). Blower motor is energized
through normally closed contacts on fan relay. When W is
de- energized, electric heat relay(s) opens.
THERMOSTAT
RED
R
GRY
G
BRN
C
WHT
W
2
WHT
BLU
E
VIO
L
O
Y
FAN HUMIDIFIER
115V M
Fig. 18 - Wiring Layout of Humidifier to Heat Pump
FAN COIL
HEAT PUMP
(CONTROL)
(CONTROL)
R
R
G
C
C
W
2
W
3
E
W
2
O
Y
RELAY
HUMIDISTAT
THERMOSTAT
R
G
W
Y
FAN HUMIDIFIER
115V M
Fig. 19 - Wiring Layout of Humidifier to Fan Coil
A95294
Fig. 20 - Wiring Layout DEHUM Option for Single- Stage
NOTE: DEHUM can only be used if a lower tap is available
8
FAN COIL
(CONTROL)
RED
R
GRY
G
WHT
W
2
WHT
BLU
W
3
VIO
E
BRN
C
HUMIDISTAT
With Electric Heat
Air Conditioning Unit
on the motor.
AIR COND.
C
Y
A95295
A160012