Controls - Carrier 42C Series Product Data

Controls

Use the Control Selection guide to make sure that all
necessary components are provided for and that the com-
ponents are compatible with the required control system.
SYSTEM DESCRIPTION
Fan Fan manually cycled
Control
(2-Pipe)
Thermostat cycles fan on-off
from speed set with fan switch.
Thermostat cycles fan on-off
from fan speed set with switch.
Mode automatically switched
by changeover sensing water
temp.
Thermostat cycles fan from
high to low on cooling and low
to off on heating.
Two- Thermostat cycles valve
position open or closed.
electric
valves
Thermostat cycles valve
(2-pipe)
open or closed. Mode auto-
matically switched by
changeover sensing water
temp.
Two- Thermostat cycles valve
position open or closed. 2° F after
electric valve closes, thermostat
valve with activates electric heater.
Auxiliary Heater cannot turn on if hot
Electric water is in coil.
Heat
Thermostat cycles valve
(2-pipe)
open or closed. Manual
changeover switch changes
thermostat to heat to activate
electric heater.
Two- Thermostat cycles valve
position open or closed. Manual
electric changeover switch changes
valve with thermostat to heat to activate
total electric heater.
electric
Thermostat cycles valve
heat
open or closed. 2° F after
(2-pipe)
valve closes, thermostat acti-
vates electric heater.
Two- Thermostat cycles cooling and
position heating valves open or closed.
electric
valves
Thermostat cycles cooling
(4-pipe)
valve open or closed. 2° F
after valve closes, thermostat
cycles heating valve open or
closed.
*If system is HEATING-ONLY or COOLING-ONLY, no changeover or bypass is required.
NOTE: Unit-mounted thermostats are not recommended with either fan-cycle control or applications with outside air dampers.
10
CONTROL SELECTION GUIDE
CHANGEOVER
THERMOSTAT ON
SUPPLY PIPE
None None
Wall mounted includes None
heat-cool switch.
Wall mounted. Yes
Heating/cooling
Thermostat
Wall or unit mounted Yes
Wall mounted includes None
heat-cool switch.
Wall or unit mounted. Yes
Heating/cooling
Thermostat
Wall or unit mounted. Yes.
Sequenced heating Two Required.
and cooling.
Wall mounted None
includes heat-cool
switch.
Wall mounted includes None
heat-cool switch.
Wall or unit mounted. None
Sequenced heating
and cooling
Wall mounted includes None
subbase with heat-
cool switch.
Wall or unit mounted. None
Sequenced heating
and cooling.
NOTE: When thermostatic fan control is selected or when
unit outside air dampers are used, unit-mounted thermo-
stats are not recommended as their use will result in poor
room temperature sensing.
VALVE
SWITCH (SW)
None Standard 3-Speed
SW
None Thermostat has inte-
gral 3-Speed SW
None Standard
3-Speed SW
None No Standard 3-Speed
Switch, ON-OFF tog-
gle SW only
Motorized (N.C.) Thermostat has inte-
3-way or 2-way, gral 3-Speed SW
no bypass required.
Motorized (N.C.) Standard 3-Speed
3-way or 2-way SW. Others have ther-
mostats with integral
3-Speed SW
Motorized 3-way or Standard 3-Speed
2-way SW. Others have ther-
mostats with integral
3-Speed SW
Motorized 3-way or Thermostat has inte-
2-way, no bypass gral 3-Speed SW
required
Motorized (N.C.) Thermostat has inte-
3-way or 2-way, gral 3-Speed SW
no bypass required
Motorized (N.C.) Standard 3-Speed
3-way or 2-way, SW
no bypass required
Motorized (N.C.) Thermostat has inte-
3-way or 2-way gral 3-Speed SW
(requires 2 valves)
Motorized (N.C.) Standard 3-Speed
3-way or 2-way SW. Others have
(requires 2 valves) thermostats with inte-
gral 3-Speed SW
FAN
NOTES
Not recommended
for high humidity
application
Unit-mounted thermostats
provide very poor room
temperature control
Best fan cycle control for
high humidity applications
Valve packages with belled
end(s) for field soldering to
coil.
Valve packages with belled
end(s) for field soldering to
coil.
Valve packages with belled
end(s) for field soldering
to coil.
Valve packages with belled
end(s) for field soldering
to coil.
Valve packages with belled
end(s) for field soldering
to coil.