![background image](http://html1.mh-extra.com/html/carrier/fb4c/fb4c_installation-manual_2561263010.webp)
10
B. Humidifier
Connect humidifier and humidistat to fan coil unit as shown in Fig.
24 and Fig. 25. The cooling lockout relay is optional.
R
G
C
E
L
O
Y
THERMOSTAT
R
R
C
O
Y
G
C
W
2
W
2
W
2
W
3
E
FAN COIL
(CONTROL)
HEAT PUMP
(CONTROL)
RED
GRY
BRN
WHT
WHT
BLU
VIO
HUMIDISTAT
RELAY
FAN HUMIDIFIER
115V
M
A95294
Fig. 24 -- Wiring Layout of Humidifier to Heat Pump
R
G
W
Y
THERMOSTAT
R
G
W
2
W
3
E
C
FAN COIL
(CONTROL)
C
Y
AIR COND.
HUMIDISTAT
FAN HUMIDIFIER
115V
RED
GRY
WHT
WHT
BLU
VIO
BRN
M
A95295
Fig. 25 -- Wiring Layout of Humidifier to Fan Coil
With Electric Heat
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.
START--UP PROCEDURES
Refer to outdoor unit Installation Instructions for system start--up
instructions and refrigerant charging method details.
UNIT COMPONENT HAZARD
Failure to follow this caution may result in product damage.
Never operate unit without a filter. Damage to blower motor
or coil may result. Factory authorized filter kits must be used
when locating the filter inside the unit. For those applications
where access to an internal filter is impractical, a
field--supplied filter must be installed in the return duct
system.
CAUTION
!
CARE AND MAINTENANCE
To continue high performance and minimize possible equipment
failure, it is essential that periodic maintenance be performed on
this equipment. Consult your local dealer as to the proper
frequency of maintenance contract.
The ability to properly perform maintenance on this equipment
requires certain mechanical skills and tools. If you do not possess
these, contact your dealer for maintenance. The only consumer
service recommended or required is filter replacement or cleaning
on a monthly basis.
FB
4C
/F
Y5
B