![background image](http://html.mh-extra.com/html/carrier/48hc-04-14/48hc-04-14_service-and-maintenance-instructions_2561012057.webp)
57
Indoor Air Quality (IAQ) Sensor Input
The IAQ input can be used for demand control ventilation
control based on the level of CO
2
measured in the space
or return air duct.
Mount the accessory IAQ sensor according to
manufacturer specifications. The IAQ sensor should be
wired to the AQ and AQ1 terminals of the controller.
Adjust the DCV potentiometers to correspond to the DCV
voltage output of the indoor air quality sensor at the
user-determined setpoint. See Fig. 74.
0
1000
2000
3000
4000
5000
6000
2
3
4
5
6
7
8
800 ppm
900 ppm
1000 ppm
1100 ppm
RANGE
CONFIGURA
TION
(ppm)
DAMPER VOLTAGE FOR MAX VENTILATION RATE
CO SENSOR MAX RANGE SETTING
2
C06039
Fig. 74 -- CO
2
Sensor Maximum Range Settings
If a separate field-supplied transformer is used to power
the IAQ sensor, the sensor must not be grounded or the
EconoMi$er IV control board will be damaged.
When using demand ventilation, the minimum damper
position represents the minimum ventilation position for
VOC
(volatile
organic
compounds)
ventilation
requirements. The maximum demand ventilation position
is used for fully occupied ventilation.
When demand ventilation control is not being used, the
minimum position potentiometer should be used to set the
occupied ventilation position. The maximum demand
ventilation position should be turned fully clockwise.
Exhaust Setpoint Adjustment
The exhaust setpoint will determine when the exhaust fan
runs based on damper position (if accessory power
exhaust is installed). The setpoint is modified with the
Exhaust Fan Setpoint (EXH SET) potentiometer. See Fig.
68. The setpoint represents the damper position above
which the exhaust fans will be turned on. When there is a
call for exhaust, the EconoMi$er IV controller provides a
45
15 second delay before exhaust fan activation to
allow the dampers to open. This delay allows the damper
to reach the appropriate position to avoid unnecessary fan
overload.
Minimum Position Control
There is a minimum damper position potentiometer on the
EconoMi$er IV controller. See Fig. 68. The minimum
damper position maintains the minimum airflow into the
building during the occupied period.
When using demand ventilation, the minimum damper
position represents the minimum ventilation position for
Volatile
Organic
Compound
(VOC)
ventilation
requirements. The maximum demand ventilation position
is used for fully occupied ventilation.
When demand ventilation control is not being used, the
minimum position potentiometer should be used to set the
occupied ventilation position. The maximum demand
ventilation position should be turned fully clockwise.
Adjust the minimum position potentiometer to allow the
minimum amount of outdoor air, as required by local
codes, to enter the building. Make minimum position
adjustments with at least 10
_
F temperature difference
between the outdoor and return-air temperatures.
To determine the minimum position setting, perform the
following procedure:
1. Calculate the appropriate mixed air temperature
using the following formula:
(T
O x
OA
) + (TR
x
RA
) =T
M
100
100
T
O
= Outdoor-Air Temperature
OA = Percent of Outdoor Air
T
R
= Return-Air Temperature
RA = Percent of Return Air
T
M
= Mixed-Air Temperature
As an example, if local codes require 10% outdoor
air
during
occupied
conditions,
outdoor-air
temperature is 60
_
F, and return-air temperature is
75
_
F.
(60 x .10) + (75 x .90) = 73.5
_
F
2. Disconnect the supply air sensor from terminals T
and T1.
3. Ensure that the factory-installed jumper is in place
across terminals P and P1. If remote damper
positioning is being used, make sure that the
terminals are wired according to Fig. 52 and that the
minimum position potentiometer is turned fully
clockwise.
4. Connect 24 vac across terminals TR and TR1.
5. Carefully
adjust
the
minimum
position
potentiometer until the measured mixed air
temperature matches the calculated value.
6. Reconnect the supply air sensor to terminals T and
T1.
Remote control of the EconoMi$er IV damper is desirable
when requiring additional temporary ventilation. If a
field-supplied remote potentiometer (Honeywell p/n:
S963B1128) is wired to the EconoMi$er IV controller, the
minimum position of the damper can be controlled from a
remote location.
To control the minimum damper position remotely,
remove the factory-installed jumper on the P and P1
terminals on the EconoMi$er IV controller. Wire the
field-supplied potentiometer to the P and P1 terminals on
the EconoMi$er IV controller. (See Fig. 73.)
Damper Movement
Damper movement from full open to full closed (or vice
versa) takes 2
1
/
2
minutes.
48H
C
Summary of Contents for 48HC*04-14
Page 94: ...94 APPENDIX IV WIRING DIAGRAMS C14007 Fig 80 48HC A04 A06 YAC Power Diagram 230 1 60 48HC ...
Page 96: ...96 APPENDIX IV WIRING DIAGRAMS C14013 Fig 82 48HC A04 A06 YAC Power Diagram 575 3 60 48HC ...
Page 97: ...97 APPENDIX IV WIRING DIAGRAMS C14018 48HC ...
Page 98: ...98 APPENDIX IV WIRING DIAGRAMS C14019 48HC ...
Page 99: ...99 APPENDIX IV WIRING DIAGRAMS C13484 Fig 83 48HC D08 D09 YAC Power Diagram 230 460 3 60 48HC ...
Page 100: ...100 APPENDIX IV WIRING DIAGRAMS C14024 Fig 84 48HC D08 D09 YAC Power Diagram 575 3 60 48HC ...
Page 101: ...101 APPENDIX IV WIRING DIAGRAMS C14027 Fig 85 48HC D12 YAC Power Diagram 230 460 3 60 48HC ...
Page 102: ...102 APPENDIX IV WIRING DIAGRAMS C14029 Fig 86 48HC D12 YAC Power Diagram 575 3 60 48HC ...
Page 104: ...104 APPENDIX IV WIRING DIAGRAMS C14032 Fig 88 48HC D14 YAC Power Diagram 230 460 3 60 48HC ...
Page 105: ...105 APPENDIX IV WIRING DIAGRAMS C12462 Fig 89 48HC D14 YAC Power Diagram 575 3 60 48HC ...
Page 123: ...123 APPENDIX IV WIRING DIAGRAMS C12690 Fig 107 PremierLink System Control Wiring Diagram 48HC ...
Page 125: ...125 APPENDIX IV WIRING DIAGRAMS C14034 Fig 109 RTU Open Wiring Diagram 48HC ...