Carrier 48FC 08-16 Series Service And Maintenance Instructions page 54

EconoMi$er IV
Fig. 77 — Return Air Temperature or Enthalpy
Sensor Mounting Location
EXH
N1
Set
N
2V 10V
EXH
P1
P
Min
Pos
T1
Open
T
DCV
Max
2V 10V
AQ1
DCV
AQ
DCV
Set
SO+
2V 10V
SO
Free
SR+
Cool
B C
SR
D
A
Fig. 78 — EconoMi$er
EconoMi$er IV
Controller
Grommet
Return Air
Sensor
Return Duct
(Field-Provided)
TR1
TR
24 24 Vac
Vac COM
HOT
_
+
1 2
5
4
3
EF EF1
®
IV W7212 Control
CONTROL POINT
CONTROL
APPROX. °F (°C)
CURVE
AT 50% RH
A 73 (23)
B 70 (21)
C 67 (19)
D 63 (17)
55
(13)
50
C
(10)
45 D
(7)
40
(4)
35
(2)
35 40 45 50 55
(2) (4) (7) (10) (13)
APPROXIMATE DRY BULB TEMPERATURE °F (°C)
Fig. 79 — Enthalpy Changeover Set Points
Indoor Air Quality (IAQ) Sensor Input
The IAQ input can be used for demand controlled ventilation
control based on the level of CO
return air duct.
Mount the accessory IAQ sensor according to manufacturer speci-
fications. The IAQ sensor should be wired to the AQ and AQ1 ter-
minals of the controller. Adjust the DCV potentiometers to corre-
spond to the DCV voltage output of the indoor air quality sensor at
the user-determined set point. See Fig. 80.
If a separate field-supplied transformer is used to power the IAQ
sensor, the sensor must not be grounded or the EconoMi$er
control board will be damaged.
When using demand controlled ventilation, the minimum
damper position represents the minimum ventilation position
for VOC (volatile organic compounds) ventilation require-
ments. The maximum demand ventilation position is used for
fully occupied ventilation.
When demand controlled ventilation is not being used, the mini-
mum position potentiometer should be used to set the occupied
ventilation position. The maximum demand ventilation position
should be turned fully clockwise.
CO Sensor Max Range Setting
6000
5000
4000
3000
2000
1000
0
2 3
Damper Voltage for Maximum Ventilation Rate
Fig. 80 — CO Sensor Maximum Range Settings
2
54
85 90 95 100 105
(29) (32) (35) (38) (41)
80
(27)
75
(24)
70
(21)
65
(18)
60
(16)
A
B
A
B
C
D
60 65 70 75 80 85 90 95 100 105
(16) (18) (21) (24) (27) (29) (32) (35) (38) (41)
measured in the space or
2
4 5 6 7 8
110
(43)
HIGH LIMIT
CURVE
110
(43)
® IV
800 ppm
900 ppm
1000 ppm
1100 ppm