Carrier 42 SERIES - Manual (Page 8)

STANDARD WIRING PACKAGES (cont)
Thermostatic Valve Control, 4-Pipe — The 4-pipe
system provides the ultimate in economy and room tem-
perature control. Both hot water and chilled water are avail-
able at any time.
Normally an automatic changeover thermostat is used, but
a manual changeover thermostat is also suitable. Two 2-way
valves, two 3-way valves, or one 2-way plus one 3-way valve
must be selected. An automatic changeover device to sense
water temperature is not required.
With this system, the fan runs continuously unless it is
manually switched to OFF position. Fan must be on before
thermostat can send signal to open the chilled water or hot
water valve.
NOTE: Wiring diagrams are for 120-v power supply. If other
voltages for heaters or controls are specified, wiring may dif-
fer from that shown.
For control package descriptions, see control components
sections entitled Remote-Mounted Controls and Unit-
Mounted Controls.
UNIT TYPE LOCATION
WIRING PACKAGE* ELECTRIC
VALVE Automatic System Manual System
Vertical Unit Mounted 24-P Available on Special Order.
Any 2- or 3-way,
2-position valve
package.
Vertical
or
Horizontal
Wall Mounted
22-G, 22-H,
23-07, 23-08
23-13, 23-14
*Packages on current price pages.
NOTES:
1. Motors thermally protected.
2. Use copper conductors only.
3. See unit nameplate for power supply. Provide disconnect means
and overload protection as required.
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