Controls - Carrier 42C Series Product Data

Controls (cont)
Automatic changeover (Summer-Winter switch) —
The automatic-changeover thermostat sensor is a 10 kilo-
ohm thermister (33ZCSENCHG) in a moistureproof and
dust-proof enclosure. Cable and temperature sensing ele-
ment are hermetically sealed in a polypropylene enclosure
with epoxy resin. Device clamps on coil supply pipe with
end snap-on clip.
The set point temperatures are factory set. When water
temperature rises above 80 F (approximately), the sensor
switches to the winter cycle. When water temperature
drops below approximately 70 F, the sensor switches to
the summer cycle. Switch reset is automatic.
Fan coil control relay board — The fan coil relay board
is used in conjunction with the Debonair thermostat or a
controller or the FC Open controller to regulate a single-
speed or multispeed fan. The fan coil relay board can also
be used to connect the fan coil controller to a line voltage
valve actuator.
The fan coil relay board is factory shipped as a PC board
with four 1 / -in. stand-offs attached for field mounting.
2
NOTE: One fan coil relay board is used for each applica-
tion. Fan coils with two or more fan motors use a fan coil
relay board for each fan motor. A maximum of three fan
coil relay boards can be wired to one fan coil control.
16
FAN COIL CONTROL RELAY BOARD
G
G2/(W)
G3/(Y)
COM
a42-4186
FAN
(VALVE)
(COOL)
HI
(HEAT)
MED
LO