Bryant 558F - Manual (Page 15)

— 15 —
C. Commissioning
The EconoMi$er saves energy when it uses outdoor air to
provide free cooling instead of mechanical air conditioning.
The EconoMi$er switchover strategy determines if the out-
door air is suitable for free cooling. The EconoMi$er chooses
the switchover strategy with the most energy savings, pro-
vided that the required sensors are connected and function-
ing normally.
IMPORTANT: If a sensor stops functioning normally
(becomes unreliable), the EconoMi$er switches to the next
best strategy.
Refer to Table 4 to determine the sensors required for each
strategy.
Differential Enthalpy Switchover Strategy
The differential enthalpy switchover strategy must be
selected manually, if required. To enable, press and hold the
CONFIG button for 30 seconds, then release. The LED will
flash twice to indicate the change of configuration.
To return to single enthalpy mode, press and hold the CON-
FIG button for 30 seconds. The LED will flash once to indi-
cate the change of configuration.
D. Discharge Air Thermistor (DAT)
The discharge air thermistor is factory-mounted on the
supply-fan housing in the fan section of the unit. The DAT is
factory-wired to the EconoMi$er Control Module.
E. CO
2
Control Setup
The CO
2
sensor monitors carbon dioxide levels. This infor-
mation is used to modify the position of the outdoor-air
dampers to admit more or less air.
1. Determine the value at which the minimum position
of the dampers will begin opening to allow a greater
amount of outdoor air to enter. The range is 800 to
1,400 ppm.
2. Locate the CO
2
SP (PPM) potentiometer and adjust
to the desired set point. See Fig. 17.
HOOD TOP
PANEL
HOOD SIDE
PANELS (2)
BAFFLE
(300
ONLY)
LOWER
FILTER
RETAINER
FILTER SUPPORT
BRACKET
HOOD DRAIN PAN
UPPER FILTER RETAINER
BAFFLE (300 ONLY)
LOWER FILTER
RETAINER
FILTER SUPPORT
BRACKET
Fig. 20 — Seal Strip Location
(Air Hood Cross-Sectional View)
NOTE: The outdoor-air hood comes with a baffle which is used on
size 300 units only; discard baffle for 180-240 units.
Fig. 21 — Outdoor-Air Hood Details
SENSOR
COVER OUTSIDE AIR SENSOR
MOUNTING
SCREW
MOUNTING SCREW
WIRING
HARNESS
SENSOR
WIRING
CONNECTIONS
Fig. 23 — Outdoor-Air Sensor Details
Fig. 22 — Outdoor-Air Sensor Location