31
Maximum fan speed is determined by the
ECat submittal. Typically, this max speed
will be the rpm set at the factory.
The fan speed can be modulated using the
0-10 VDC input signal.
To check fan output from the factory, the
potentiometer can be dialed to 100%. By
sending a 5V signal*, for instance, the rpm
can be measured and this reading can be
converted to cubic feet of air moved by the
fan.
It is advised that a medium range signal* be
utilized for this procedure. The highest
signal sent by the controller can then be
determined by adjustment.
Operation
Unit operations must be controlled with
thermostat or unit controller, never at the
main power supply, except for emergency or
complete shutdown of the unit.
Thermostat Operation
Heating
Thermostat system switch - "Heat"
Thermostat fan switch - "Auto" or "On"
Thermostat temperature set to desired point.
Cooling
Thermostat system switch - "Cool"
Thermostat fan switch - "Auto" or "On"
Thermostat temperature set to desired point.
Air Circulation
Thermostat system switch - "Off"
Thermostat fan switch - "Auto" or "On"
No change of the thermostat temperature.
With these settings, the supply blower will
run continuously but the supply air will not
be heated, cooled, or dehumidified.
System Off
Thermostat system switch - "Off"
Thermostat fan switch - "Auto"
No change of the thermostat temperature.
With these settings the system is shut down,
with the exception of control system power.
Night and Weekend Unoccupied Operation
To reduce the operating time of the unit when
the space is unoccupied, such as nights and
weekends, it is recommended that the
temperature setting be raised about -15 °C
(5°F) while unoccupied during the cooling
season and lowered about -12.2°C (10°F)
during the heating season.
Split System DX Cooling Operation and
Control
When a call for cooling (G and Y1, Y2, etc.)
is made the supply blower motors and
compressors will energize.
Chilled Water or Non-Compressorized
DX Cooling Operation
Valve controls for chilled water cooling coil
and non-compressorized DX coil are by
others.
Steam or Hot Water Preheating
Operation
Valve control for steam and hot water heating
coils are by others. Heating is accomplished
by passing steam or hot water through the
steam or hot water coil assembly.
To Next Page
