Ecto Adjustments; Setpoint Control Option - Lennox Prodigy M2 Application Manual

7.12.2. Default Operation
The M2 has a 0−10VDC IAQ input for a standard 0−2000ppm CO
500 ppm ( start open" setpoint) and reaches full open at a CO
100%. Determine damper travel position using the following formula.
% Damper Travel = CO
Example: At a CO
2
% Damper Travel =
Use Displaying Sensor Inputs" section to read CO

7.12.3. ECTO Adjustments

Default IAQ economizer operation is based on common or average applications. Adjustments may be made to the IAQ
ECTO parameters to alter operation or meet required specifications. Use the ECTO Control Parameters" section to change
ECTO parameters 5.16 through 5.22.
Select a DCV or OAC mode with ECTO 5.26. Modes 4 and 5 will bring on the unit blower when DCV calls for maximum
damper open, and returns to auto−blower when DCV damper returns to 0. The other modes only operate when the unit
blower is on, but will not bring it on themselves.
Some applications require a different CO
open" (ECTO 5.18) CO
2
travel.
NOTE − When changing CO
% Damper Travel =
Example: An application requires the dampers open at 800 CO
If the CO level in the space reads 1000 ppm, calculate the damper percent open as follows.
2
% Damper Travel = 1000 − 800

7.12.3.1. Setpoint Control Option

Setpoint Control mode is commonly used in areas with high occupancy and frequent change out such as classrooms or
conference rooms.
In applications requiring this on/off damper response to CO
full open" (ECTO 5.18) setpoint. The dampers will drive to fully−open position immediately. Figure 15 shows the setpoint
control option.
Change ECTO 5.19 and 5.20 to set the minimum outdoor temperature limits. Change ECTO 5.21 and 5.22 to set the maxi-
mum temperature value.
IMPORTANT − Mixed air temperatures less than 45°F (7°C) on units with an aluminized heat exchanger or less than 30°F
(−1°C) on stainless steel heat exchangers will void the manufacturer's warranty.
506457−01 05/10
ppm − Start Open ppm
2
5
level of 750ppm, the damper will be approximately 50% open:
750−500
5
100
66
33
Min. Position
0
500
ECTO 5.17
CO (ppm)
2
Figure 14. Default DCV Operation
setpoint range than default settings. Damper start open" (ECTO 5.17) and full
2
setpoints may be adjusted from 0 to 1992ppm. Use the following formula to determine damper
setpoint range, start open" setpoint should be less than full-open" setpoint.
2
CO ppm − Start Open ppm X
2
Full Open − Start Open
or 200 or .5
1200 − 800 400
sensor. The economizer starts opening at a CO
2
level of 1000ppm ( full open" setpoint). The damper opens to
2
= 50%
ppm. Figure 14 shows default or proportional operation.
2
Low Temp. Operation
40°F ECTO 5.20
30°F
20°F
10°F ECTO 5.19
1000
ECTO 5.18
MaxOpen (ECTO 5.16)
ppm and reach full open at 1200.
2
= 0.5 x 100 = 50%
levels, set the start open" (ECTO 5.17) setpoint higher than the
2
Page 30
7.
High Temp. Operation
75°F ECTO 5.21
85°F
95°F
105°F ECTO 5.22
Economizer
level of
2