Bryant DURAPAC 579F - Manual (Page 17)

— 17 —
Table 11 — EconoMi$erIV Sensor Usage
*CRENTDIF004A00 and CRTEMPSN002A00 accessories are used on many different base units. As such, these kits may contain parts that will not be needed
for installation.
†CGCDXSEN004A00 is an accessory CO
2
sensor.
**CGCDXASP001A00 is an accessory aspirator box required for duct-mounted applications.
Differential Enthalpy Control
For differential enthalpy control, the EconoMi$erIV controller
uses two enthalpy sensors (HH57AC078 and
CRENTDIF004A00), one in the outside air and one in the
return airstream on the EconoMi$erIV frame. The
EconoMi$erIV controller compares the outdoor air enthalpy to
the return air enthalpy to determine EconoMi$erIV use. The
controller selects the lower enthalpy air (return or outdoor) for
cooling. For example, when the outdoor air has a lower
enthalpy than the return air and is below the set point, the
EconoMi$erIV opens to bring in outdoor air for free cooling.
Replace the standard outside air dry bulb temperature sen-
sor with the accessory enthalpy sensor in the same mounting
location. See Fig. 24. Mount the return air enthalpy sensor
in the return airstream. See Fig. 29. The outdoor enthalpy
changeover set point is set with the outdoor enthalpy set
point potentiometer on the EconoMi$erIV controller. When
using this mode of changeover control, turn the enthalpy set
point potentiometer fully clockwise to the D setting.
NOTE: Remove 620-ohm resistor if differential enthalpy sen-
sor is installed.
APPLICATION
ECONOMI$ERIV WITH OUTDOOR AIR
DRY BULB SENSOR
ECONOMI$ERIV WITH SINGLE
ENTHALPY SENSOR
Accessories Required Accessories Required
Outdoor Air Dry Bulb None. The outdoor air dry bulb sensor is factory installed. CRTEMPSN002A00*
Differential Dry Bulb CRTEMPSN002A00* (2) CRTEMPSN002A00*
Single Enthalpy HH57AC078 None. The single enthalpy sensor is factory installed.
Differential Enthalpy
HH57AC078
and
CRENTDIF004A00*
CRENTDIF004A00*
CO
2
for DCV Control using a
Wall-Mounted CO 2 Sensor
CGCDXSEN004A00
CO
2
for DCV Control using a
Duct-Mounted CO 2 Sensor
CGCDXSEN004A00†
and
CGCDXASP001A00**
Fig. 27 — EconoMi$erIV Controller Potentiometer
and LED Locations
LED ON
LED ON
LED ON
LED ON
LED OFF
19
18
LED OFF
LED OFF
LED OFF
17
16
15
14
13
12
11
10
9
40 45 50 55 60 65 70 75 80 85 90 95 100
DEGREES FAHRENHEIT
mA
D
C
B
A
Fig. 28 — Outside Air Temperature
Changeover Set Points
IAQ
SENSOR
RETURN AIR
TEMPERATURE
OR ENTHALPY
SENSOR
TR 1
24 Va c COM
TR
24 Va c HO T
1 2
3 4
5
EF EF 1
+
_
P1
T1
P
T
N EXH
2V 10 V EX H Set
Se t 2V 10 V
2V 10 V DC V DC V
Fr ee Co ol B C
A D SO +
SR + SR
SO
AQ1 AQ
DC V
Mi n Pos
Op en
Ma x
N1
Fig. 29 — Return Air Temperature or Enthalpy
Sensor Mounting Location