Bryant F User Manual
Page 57
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The same equation can be used to determine the occupied
or maximum ventilation rate to the building. For example,
an output of 3.6 volts to the actuator provides a base
ventilation rate of 5% and an output of 6.7 volts provides
the maximum ventilation rate of 20% (or base plus 15 cfm
per person). Use Fig. 72 to determine the maximum
setting of the CO
2
sensor. For example, an 1100 ppm
setpoint relates to a 15 cfm per person design. Use the
1100 ppm curve on Fig. 72 to find the point when the CO
2
sensor output will be 6.7 volts. Line up the point on the
graph with the left side of the chart to determine that the
range configuration for the CO
2
sensor should be 1800
ppm. The EconoMi$er IV controller will output the 6.7
volts from the CO
2
sensor to the actuator when the CO
2
concentration in the space is at 1100 ppm. The DCV
setpoint may be left at 2 volts since the CO
2
sensor
voltage will be ignored by the EconoMi$er IV controller
until it rises above the 3.6 volt setting of the minimum
position potentiometer.
Once the fully occupied damper position has been
determined, set the maximum damper demand control
ventilation potentiometer to this position. Do not set to the
maximum position as this can result in over-ventilation to
the space and potential high humidity levels.
CO
2
Sensor Configuration
The CO
2
sensor has preset standard voltage settings that
can be selected anytime after the sensor is powered up.
(See Table 23.)
Use setting 1 or 2 for Bryant equipment. (See Table 23.)
1. Press Clear and Mode buttons. Hold at least 5
seconds until the sensor enters the Edit mode.
2. Press Mode twice. The STDSET Menu will appear.
Table 23 – CO
2
Sensor Standard Settings
SETTING
EQUIPMENT
OUTPUT
VENTILATION
RATE
(cfm/Person)
ANALOG
OUTPUT
CO
2
CONTROL
RANGE
(ppm)
OPTIONAL
RELAY SETPOINT
(ppm)
RELAY
HYSTERESIS
(ppm)
1
Interface w/Standard
Building Control System
Proportional
Any
0---10V
4---20mA
0---2000
1000
50
2
Proportional
Any
2---10V
7---20mA
0---2000
1000
50
3
Exponential
Any
0---10V
4---20mA
0---2000
1100
50
4
Economizer
Proportional
15
0---10V
4---20mA
0---1100
1100
50
5
Proportional
20
0---10V
4---20mA
0---900
900
50
6
Exponential
15
0---10V
4---20mA
0---1100
1100
50
7
Exponential
20
0---10V
4---20mA
0---900
900
50
8
Health & Safety
Proportional
—
0---10V
4---20mA
0---9999
5000
500
9
Parking/Air Intakes/
Loading Docks
Proportional
—
0---10V
4---20mA
0---2000
700
50
580J