IEC Vertical F*C Series Installation, Operation & Maintenance Manual page 13

Two control methods are available:
1. Use the standard automatic changeover thermostat
with a dead band between heating and cooling.
2. Use a manual changeover thermostat. With this
method only one changeover is required. Be sure
to include a 2-way or 3-way electric valve with this
system.
Thermostat 2-Pipe Total Electric Heat with Valve
Control— With this system type, 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 to have heating or cooling at any time of
the year. The fan may run continuously unless it is manually
switched to OFF or AUTO 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.
International Environmental Corporation • Vertical F*C Series Fan Coil Installation, Operation, & Maintenance Manual
IEC Vertical F*C Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
Thermostatic Electric Valve Control, 4-Pipe — This system
configuration provides the complete heating requirement
for the space by the hydronic heating coil. It is therefore
possible to have heating or cooling at any time of the year.
The fan may run continuously unless it is manually switched
to OFF or AUTO position. Fan must be on before thermostat
can send signal to open chilled water valve or the hot water
valve.
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
valves must also be used so that the chilled water valve is
closed whenever the heating valve is open. No changeover
device to sense water temperature is necessary.
NOTE: Wiring diagrams are for typical applications. If other
voltages for heaters or controls are specified, wiring may
differ from that shown. See Figure 11 for line voltage
control. See Figure 12 for 24 V control. Refer to wiring
diagram on unit blower housing for unit specific wiring.
Incoming
Power
Figure 9: Standard Fan Switch
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To Motor Speeds
L
M
H
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