12
COMMISSIONING
The EconoMi$er saves energy when it uses OA to provide
free cooling instead of mechanical air conditioning. The
EconoMi$er controller switchover strategy determines if the
OA is suitable for free cooling. The controller chooses the
switchover strategy with the most energy savings, provided the
required sensors are connected and functioning normally.
CO
2
Control Set Up —
If a CO
2
sensor is not being used,
proceed to the next section. If a CO
2
sensor is being used, per-
form the following:
1. Determine the value at which you want the minimum
position of the dampers to 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. 40.
Mechanical Cooling Lockout —
Determine the
outdoor-air temperature at which you want the mechanical
cooling (compressors) to be disabled. Locate the mechanical
cooling lockout (MECH CLG LOCKOUT) potentiometer. To
disable this feature, turn the potentiometer counterclockwise
(CCW) to the OFF position. Otherwise, set the value between
10 and 60 F. Mechanical cooling will not operate when the out-
door air temperature is below this value. See Fig. 40.
Dry Bulb Changeover Set Up —
Determine the dry bulb
changeover set point from Table 3. The settings are A, B, C and
D. Locate the ECON SP potentiometer and set the dry bulb
changeover set point. See Fig. 40. When the OAT is above this set
point, the damper is limited to minimum position setting.
Table 3 — Changeover Set Points
*Field-installed accessory.
If a potentiometer fails, its setting will default to the values
in Table 4.
Table 4 — Default Potentiometer Settings
Ventilation Air (Minimum Position Set Up) —
If ven-
tilation air is not required, proceed to Step 5. If ventilation air is
required, perform the following:
1. The indoor fan must be on to set the ventilation air.
Either put the thermostat in the continuous fan mode or
jumper the R and G terminals at the rooftop unit con-
nection board.
2. Locate the minimum position (MIN POS) potentiome-
ter. Turn the potentiometer full CCW to fully close the
outdoor air dampers. Turn the potentiometer gradually
clockwise (CW) to the desired position. See Fig. 40.
3. Replace the filter access panel. See Fig. 3. Ensure the
filter access panel slides along the tracks and is
securely engaged.
4. Calculate the minimum airflow across the
EconoMi$er.
a. Calculate % of outside air using the following
formula.
% Outdoor air through EconoMi$er
b. Multiply total CFM by percentage outdoor air, this
gives outdoor air volume in CFM.
5. Turn on base unit power.
NOTE: The EconoMi$er begins operation three min-
utes after power up.
6. See Figs. 41-45 for barometric relief damper
characteristics.
IMPORTANT: If a sensor stops functioning nor-
mally, the EconoMi$er controller switches to a strat-
egy with reliable sensors.
SETTINGS
A
B
C
D
Dry Bulb (°F)
73
69
66
63
Single Enthalpy* (Btu/lb)
27
25
24
22
Differential Temperature*
(°F, Not Adjustable)
2
2
2
2
Differential Enthalpy*
(Btu/lb, Not Adjustable)
1
1
1
1
POTENTIOMETER
DEFAULT SETTING
CO
2
SP (PPM)
1,000
MECH CLG LOCKOUT
47°
ECON SP
D
MIN POS (%)
20
% Outdoor air =
Mixture Temp – Return Air Temp
Outdoor Temp – Return Air Temp
Personal Injury Hazard. Avoid possible injury by keep-
ing fingers away from damper blades.
Fig. 38 — Location of the Switches for a
3 to 6 Ton EconoMi$er
0
10
40 60
70
60
4050
70
80
SWITCH
ADJUSTERS
(DEGREES)
SW #2
SW #1
Fig. 39 — Location of the Switches for a
7
1
/
2
to 12
1
/
2
Ton EconoMi$er
Fig. 40 — EconoMi$er Control Adjustment
Potentiometers (Factory Settings)
