Bryant DURAPAC 579F Installation, Start-Up And Service Instructions Manual page 20

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. 32 to determine the maximum setting of the CO
For example, a 1100 ppm set point relates to a 15 cfm per
person design. Use the 1100 ppm curve on Fig. 32 to find the
point when the CO sensor output will be 6.7 volts. Line up
2
the point on the graph with the left side of the chart to deter-
mine that the range configuration for the CO
be 1800 ppm. The EconoMi$erIV controller will output the
6.7 volts from the CO sensor to the actuator when the CO
2
concentration in the space is at 1100 ppm. The DCV set point
may be left at 2 volts since the CO
ignored by the EconoMi$erIV controller until it rises above
the 3.6 volt setting of the minimum position potentiometer.
Once the fully occupied damper position has been deter-
mined, 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 Sensor Configuration
2
The CO sensor has preset standard voltage settings that
2
can be selected anytime after the sensor is powered up. See
Table 12.
Use setting 1 or 2 for Bryant equipment. See Table 12.
1. Press Clear and Mode buttons. Hold at least 5 sec-
onds until the sensor enters the Edit mode.
2. Press Mode twice. The STDSET Menu will appear.
3. Use the Up/Down button to select the preset number.
See Table 12.
SETTING EQUIPMENT
1
Interface w/Standard
2
Building Control System
3
4
5
Economizer
6
7
8 Health & Safety
Parking/Air Intakes/
9
Loading Docks
LEGEND
ppm — Parts Per Million
sensor.
2
sensor should
2
2
sensor voltage will be
2
Table 12 — CO Sensor Standard Settings
2
VENTILATION
OUTPUT RATE
(cfm/Person)
Proportional Any
Proportional Any
Exponential Any
Proportional 15
Proportional 20
Exponential 15
Exponential 20
Proportional —
Proportional —
—
4. Press Enter to lock in the selection.
5. Press Mode to exit and resume normal operation.
The custom settings of the CO
time after the sensor is energized. Follow the steps below to
change the non-standard settings:
1. Press Clear and Mode buttons. Hold at least 5 sec-
onds until the sensor enters the Edit mode.
2. Press Mode twice. The STDSET Menu will appear.
3. Use the Up/Down button to toggle to the NONSTD
menu and press Enter.
4. Use the Up/Down button to toggle through each of
the nine variables, starting with Altitude, until the
desired setting is reached.
5. Press Mode to move through the variables.
6. Press Enter to lock in the selection, then press Mode
to continue to the next variable.
Dehumidification of Fresh Air with DCV Control
Information from ASHRAE indicates that the largest humid-
ity load on any zone is the fresh air introduced. For some
applications, a field-supplied energy recovery unit can be
added to reduce the moisture content of the fresh air being
brought into the building when the enthalpy is high. In most
cases, the normal heating and cooling processes are more
than adequate to remove the humidity loads for most com-
mercial applications.
If normal rooftop heating and cooling operation is not ade-
quate for the outdoor humidity level, an energy recovery unit
and/or a dehumidification option should be considered.
CO
2
ANALOG
CONTROL RANGE
OUTPUT
(ppm)
0-10V
0-2000
4-20 mA
2-10V
0-2000
7-20 mA
0-10V
0-2000
4-20 mA
0-10V
0-1100
4-20 mA
0-10V
0- 900
4-20 mA
0-10V
0-1100
4-20 mA
0-10V
0- 900
4-20 mA
0-10V
0-9999
4-20 mA
0-10V
0-2000
4-20 mA
20 —
sensor can be changed any-
2
OPTIONAL RELAY
RELAY SETPOINT HYSTERESIS
(ppm) (ppm)
1000 50
1000 50
1100 50
1100 50
900 50
1100 50
900 50
5000 500
700 50