24
Time-out and Screen Saver
When no buttons have been pressed for 10 minutes, the LCD
displays a screen saver, which cycles through the Status items.
Each Status item displays in turn and cycles to the next item af-
ter 5 seconds.
START-UP AND OPERATION
Cooling with EconoMi$er X
For Occupied mode operation of EconoMi$er X, there must be
a 24-v signal at terminals R and OCC (provided through PL6-3
from the unit’s IFC coil). Removing the signal at OCC places
the EconoMi$er X control in Unoccupied mode. See Table 14
for Damper Position Control.
During Occupied mode operation, indoor fan operation will be
accompanied by economizer dampers moving to Minimum Po-
sition set point for ventilation. If indoor fan is off, dampers will
close. During Unoccupied mode operation, dampers will re-
main closed unless a Cooling (by free cooling) or DCV de-
mand is received.
When free cooling using outside air is not available, the unit
cooling sequence will be controlled directly by the space ther-
mostat. Outside air damper position will be closed or Minimum
Position as determined by Occupancy mode and fan signal.
When free cooling is available as determined by the appropri-
ate changeover command (dry bulb, outdoor enthalpy, differen-
tial dry bulb, or differential enthalpy), a call for cooling (Y1
closes at the thermostat) will cause the economizer control to
modulate the dampers open and closed to maintain the unit
supply air temperature. Default supply air temperature is 53°F,
with a range of 38°F to 70°F. Compressor will not run.
Should 100% outside air not be capable of satisfying the space
temperature, space temperature will rise until Y2 is closed. The
economizer control will call for compressor operation. Damp-
ers will modulate to maintain SAT set point concurrent with
Compressor 1 operation. The “Low T Lock” setting (default
32°F) will lock out compressor operation when outside air tem-
perature is below set point.
When space temperature demand is satisfied (thermostat Y1
opens), the dampers will return to Minimum Damper position
if indoor fan is running or fully closed if fan is off.
If accessory power exhaust is installed, the power exhaust fan
motors will be energized by the economizer control as the
dampers open above the EXH1 SET set point and will be ener-
gized as the dampers close below the EXH1 SET set point.
Damper movement from full closed to full open (or vice versa)
will take between 1
1
/
2
and 2
1
/
2
minutes.
Heating with EconoMi$er X
During Occupied mode operation, indoor fan operation will be
accompanied by economizer dampers moving to Minimum Po-
sition set point for ventilation. If indoor fan is off, dampers will
close. During Unoccupied mode operation, dampers will remain
closed unless a DCV demand is received.
When the room temperature calls for heat (W1 closes), the
heating controls are energized.
Table 13 — Economizer Module — Right Hand
Terminal Blocks
LABEL
TYPE
DESCRIPTION
Top Right Terminal Block
n/a
The first terminal is not used
AUX2 I
24 vac IN
Shut Down (SD) or Heat (W)
Conventional only
and
Heat Pump Changeover (O?B) in Heat
Pump mode.
OCC
24 vac IN
Occupied / Unoccupied Input
E - GND
E-GND
Earth Ground - System Required
EXH1
24 vac OUT Exhaust Fan 1 Output
AUX1 O
24 vac OUT
Programmable:
Exhaust fan 2 output
or
ERV
or
System alarm output
Bottom Right Terminal Block
Y2-1
24 vac IN
Y2 in - Cooling Stage 2 Input from space
thermostat
Y2-O
24 vac OUT Y2 out - Cooling Stage 2 Output to stage 2
mechanical cooling
Y1-I
24 vac IN
Y1 in - Cooling Stage 2 Input from space
thermostat
Y1-O
24 vac OUT Y1 out - Cooling Stage 2 Output to stage 2
mechanical cooling
C
COM
24 vac Common
R
24 vac
24 vac Power (Hot)
Table 14 — Damper Position Control, 2-Speed Fan Motor, Economizer Cooling Not Available
INPUT
VOLTAGE
OCC
0 - V
24 - V
24 - V
24 - V
24 - V
Y1
0 - V
0 - V
24 - V
24 - V
0 - V
Y2
0 - V
0 - V
0 - V
24 - V
0 - V
W1
0 - V
0 - V
0 - V
0 - V
24 - V
SUPPLY FAN
MOTOR SPEED
OFF
LOW
LOW
HIGH
HIGH
DAMPER POSITION
NO CO
2
SENSOR
CLOSED
MIN POS-L
MIN POS-L
MIN POS-H
MIN POS-H
W/ CO
2
SENSOR
CLOSED
FROM
VENTMIN L
TO
VENTMAX L
FROM
VENTMIN L
TO
VENTMAX L
FROM
VENTMIN H
TO
VENTMAX H
FROM
VENTMIN H
TO
VENTMAX H
