Carrier 42 SERIES - Manual (Page 7)

Thermostatic 2-Pipe Total Electric Heat with-
Valve Control —
With this system, the complete heat-
ing requirement for the space is provided by the electric heater;
the water system is never changed over for heating. It is there-
fore possible, just as with 4-pipe systems, to have heating or
cooling at any time of the year.
The fan runs continuously unless it is manually switched
to OFF position. Fan must be on before thermostat can send
signal to open chilled water valve or turn on electric heater.
Normally, an automatic changeover thermostat with a dead
band between heating and cooling is used, but a manual
changeover thermostat is also suitable. A 2-way or 3-way
valve must also be used so that the chilled water is off when-
ever the heater is on. No changeover device to sense water
temperature is necessary.
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-Q Available on Special Order.
Any 2- or 3-way,
2-position valve
Package.
Vertical
or
Horizontal
Wall Mounted
22-J, 22-K,
23-09, 23-10
23-15, 23-16
*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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