Controls - Carrier 42C Series Product Data

Controls

Use the Control Selection Guide table 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)
Two- Thermostat cycles valve
Position open or closed.
Electric
Valves
(2-pipe)
Thermostat cycles valve
open or closed. Mode auto-
matically switched by
changeover sensing water
temp.
Two- Thermostat cycles valve
Position open or closed. Thermostat
Electric activates electric heater.
Valve with Heater cannot turn on if hot
Auxiliary water is in coil.
Electric
Heat
(2-pipe)
Two- Thermostat cycles valve
Position open or closed.Thermostat
Electric activates electric heater.
Valve with
Total
Electric
Heat
(2-pipe)
Two- Thermostat cycles cooling
Position valve open or closed. Ther-
Electric mostat cycles heating valve
Valves open or closed.
(4-pipe)
LEGEND
N.C. — Normally 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.
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.
CONTROL SELECTION GUIDE
CHANGEOVER
THERMOSTAT ON
SUPPLY PIPE
None None
Wall or unit None
mounted includes
heat-cool switch.
Wall or unit Yes
mounted.
Heating/cooling
Thermostat
Wall or unit Yes.
mounted. Two Required.
Sequenced heating
and cooling.
Wall or unit None
mounted.
Sequenced heating
and cooling
Wall or unit None
mounted.
Sequenced heating
and cooling.
FAN
VALVE
SWITCH
None 3-Speed switch
Motorized (N.C.) Thermostat has
3-way or 2-way, integral 3-speed
no bypass switch
required.
Motorized (N.C.) Thermostat has
3-way or 2-way integral 3-speed
switch
Motorized 3-way Thermostat has
or 2-way integral 3-speed
switch
Motorized (N.C.) Thermostat has
3-way or 2-way, integral 3-speed
no bypass switch
required
Motorized (N.C.) Thermostat has
3-way or 2-way integral 3-speed
(requires 2 switch
valves)
NOTES
Not recommended for
high humidity applica-
tion
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.
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