Carrier 42V - Manual (Page 61)

61
Thermostat 2-Pipe Total Electric Heat with Valve Con-
trol — With this system, the complete heating requirement for
the space is provided by the electric heater; the water system is
never changed over for heating. It is therefore 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 whenever 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 differ
from that shown. See Fig. 61 and 62 for line voltage control.
See Fig. 63 and 64 for 24-v control.
Fig. 60 — 42C,S,V (except VG), and 42D (600-1000 cfm) 2-Pipe Heating and Cooling with
Auxiliary Heat — Remote/Wall-Mounted Debonair ® Thermostat (24-v)
a42-4067
NEC CLASS 2 WIRING