Bryant DURAPAC PLUS SERIES 542J User Manual
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B. EconoMi$erIV Standard Sensors
Outdoor Air Temperature (OAT) Sensor
The outdoor air temperature sensor (HH57AC074) is a 10 to
20 mA device used to measure the outdoor-air temperature.
The outdoor-air temperature is used to determine when the
EconoMi$erIV can be used for free cooling. The sensor must
be field-relocated. See Fig. 20. The operating range of tem-
perature measurement is 40 to 100 F.
Supply Air Temperature (SAT) Sensor
The supply air temperature sensor is a 3 K thermistor
located at the inlet of the indoor fan. See Fig. 21. This sensor
is factory installed. The operating range of temperature
measurement is 0° to 158 F. See Table 6 for sensor tempera-
ture/resistance values.
The temperature sensor looks like an eyelet terminal with
wires running to it. The sensor is located in the “crimp end”
and is sealed from moisture.
Low Temperature Compressor Lockout Switch
The EconoMi$erIV is equipped with an ambient tempera-
ture lockout switch located in the outdoor air stream which
is used to lockout the compressors below a 42 F ambient tem-
perature. See Fig. 20.
Table 6 — Supply Air Sensor Temperature/
Resistance Values
C. EconoMi$erIV Control Modes
Determine the EconoMi$erIV control mode before set up of the
control. Some modes of operation may require different sensors.
Refer to Table 7. The EconoMi$erIV is supplied from the factory
with a supply air temperature sensor, a low temperature com-
pressor lockout switch, and an outdoor air temperature sensor.
This allows for operation of the EconoMi$erIV with outdoor air
dry bulb changeover control. Additional accessories can be
added to allow for different types of changeover control and
operation of the EconoMi$erIV and unit.
Outdoor Dry Bulb Changeover
The standard controller is shipped from the factory config-
ured for outdoor dry bulb changeover control. The outdoor
air and supply air temperature sensors are included as stan-
dard. For this control mode, the outdoor temperature is com-
pared to an adjustable set point selected on the control. If the
outdoor-air temperature is above the set point, the
EconoMi$erIV will adjust the outdoor-air dampers to mini-
mum position. If the outdoor-air temperature is below the set
point, the position of the outdoor-air dampers will be con-
trolled to provide free cooling using outdoor air. When in this
mode, the LED next to the free cooling set point potentiome-
ter will be on. The changeover temperature set point is con-
trolled by the free cooling set point potentiometer located on
the control. See Fig. 23. The scale on the potentiometer is A,
B, C, and D. See Fig. 24 for the corresponding temperature
changeover values.
Differential Dry Bulb Control
For differential dry bulb control the standard outdoor dry
bulb sensor is used in conjunction with an additional acces-
sory return air sensor (part number CRTEMPSN002A00).
The accessory sensor must be mounted in the return
airstream. See Fig. 25.
In this mode of operation, the outdoor-air temperature is
compared to the return-air temperature and the lower tem-
perature airstream is used for cooling. When using this mode
of changeover control, turn the free cooling/enthalpy set point
potentiometer fully clockwise to the D setting. See Fig. 23.
Table 7 — EconoMi$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.
TEMPERATURE (F)
RESISTANCE (ohms)
–58
200,250
–40
100,680
–22
53,010
–4
29,091
14
16,590
32
9,795
50
5,970
68
3,747
77
3,000
86
2,416
104
1,597
122
1,080
140
746
158
525
176
376
185
321
194
274
212
203
230
153
248
116
257
102
266
89
284
70
302
55
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**