Once base ventilation has been determined, set the mini-
mum damper position potentiometer to the correct position.
The same equation can be used to determine the occupied or
maximum ventilation rote to the building. For example, fin output
of 3.6 volts to the actuator provides a base ventilation rate of 5%
and finoutput of 6.7 volts provides file maximum ventilation rate
of 20% (or base plus 15 cfin per pelion). Use Fig. 23 to deter-
mine file maximum setting of the CO2 sensor. For example, a
1100 ppm set point relates to a 15 cfln per pelion design. Use the
1100 ppm curve on Fig. 23 to find the point when file CO2 sensor
output will be 6.7 volts. Line up the point on file graph with file
left side of the chin1 to detemiine that the range configuration for
the CO2 sensor should be 1800 pprn. The EconoMi$er IV con-
troller will output file 6.7 volts from file CO2 sensor to file actua-
tor when the CO2 concentration in the space is at 1100 ppm. The
DCV set point may be left fit 2 volts since the C(_ sensor voltage
will be ignored by the EconoMi$er IV controller until it rises
above the 3.6 volt setting of the minimum position potentiometel:
Once the fully occupied dmnper 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 find
potential high humidity levels.
CO2 Sensor Configuration -- The CO2 sensor has preset
standard voltage settings that can be selected anytime after the
sensor is powered up. See Table 4.
Use setting 1 or 2 for Career equipment.
1. Press Clear and Mode buttons. Hold fit least 5 seconds
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 numbel: See
Table 4.
4. Press Enter to lock in the selection.
5. Pless Mode to exit and resume normfd operation.
The custom settings of the CO2 sensor can be changed any-
time after the sensor is energized. Follow the steps below to
change file non-stan&trd settings:
1. Pless Clear and Mode buttons. Hold fit least 5 seconds
until the sensor enters the Edit mode.
2. Pless Mode twice. The STDSET Menu will appem:
3. Use the Up/Down button to toggle to the NONSTD menu
find press Enter.
4. Use the Up/Down button to toggle through each of the
nine variables, starting with Altitude, until the desired set-
ting 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 (Demand Con-
trolled Ventilation)Control -- Infomiation fi_om ASHRAE
(American Society of Heating, Refiigeration, and Air Condi-
tioning Engineel_) indicates that the largest humidity load on
any zone is the fiesh air introduced. For some applications, a
device such as a 62AQ energy recovery unit is added to reduce
the moisture content of the fiesh 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 commerckfl applications.
This makes the control of the of the dehumidification device
simple when using the enthalpy or differential enthfflpy sensor.
The enthalpy sensor or differentiffl enthalpy sensor is installed
on the equipment to determine economizer operation. The high
enthalpy signal fiom the enthfflpy sensor or differential en-
thalpy sensor can be used to turn on the outdoor air moisture
removal device any time fiesh air is required for the space.
The energy recovery device should be sized for maximum
latent and sensible conditioning fit maximum ventilation on a
design &ty. A calculation for leaving-air temperature on a low
mnbient, low ventilation &ty should fflso be done to detemiine
the mixed-ffir temperature of the return and pre-conditioned
outside ail_ The design should produce an ffir temperature
somewhat near room conditions to prevent reheat of the air
mixture. The energy recovel_y device should be interlocked
with the heat to turn off the device when in the heat mode.
Step 11 -- Install All Accessories --After all of
the factory-installed options have been adjusted, install all
field-instfdled accessories. Refer to the accessory installation
instructions included with each accessory. Consult the Cmrier
Price Pages or RTU (rooftop unit) Building software for acces-
sory package numbers for particular applications.
SETTING
1
2
3
4
5
6
7
8
9
Table 4 -- 002 Sensor Standard Settings
ANALOG
EQUIPMENT OUTPUT
Interface With Standard
Building Control System
Economizer
Health and Safety
Parking/Air Intakes/
Loading Docks
OUTPUT
Proportional
Proportional
Exponential
Proportional
Proportional
Exponential
Exponential
Proportional
Proportional
VENTILATION
RATE
(efm/Pereon)
Any
Any
Any
15
20
15
20
0-10V
4-20 mA
2-10V
7-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
0-10V
4-20 mA
CO2
CONTROLRANGE
(ppm)
0-2000
0-2000
0-2000
0-1100
0- 900
0-1100
0- 900
0-9999
0-2000
OPTIONAL
RELAY SETPOINT
(ppm)
1000
1000
1100
1100
900
1100
900
5000
700
RELAY
HYSTERESIS
(ppm)
50
50
50
50
50
50
50
50O
50
19
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