Filter
Top Products
—18—
Table 3 — Supply Air Sensor
Temperature/Resistance Values
G. EconoMi$er IV Control Modes
Determine the EconoMi$er IV control mode before set up of the
control. Some modes of operation may require different sensors.
Refer to Table 4. The EconoMi$er IV is supplied from the fac-
tory with a supply air temperature sensor and an outdoor air
temperature sensor. This allows for operation of the
EconoMi$er IV 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$er
IV and unit.
Outdoor Dry Bulb Changeover
The standard controller is shipped from the factory config-
ured for outdoor dry bulb changeover control. The outdoor
air and supply air temperature sensors are included as stan-
dard. For this control mode, the outdoor temperature is com-
pared to an adjustable set point selected on the control. If the
outdoor-air temperature is above the set point, the
EconoMi$er IV will adjust the outside 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. 32. The scale on the potentiometer is A,
B, C, and D. See Fig. 33 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 dry bulb sensor (part number CRTEMPSN002A00). The
accessory sensor must be mounted in the return airstream.
See Fig. 34. Wiring is provided in the EconoMi$er IV wiring
harness. See Fig. 27.
In this mode of operation, the outdoor-air temperature is
compared to the return-air temperature and the lower tem-
perature airstream is used for cooling. When using this mode
of changeover control, turn the enthalpy set point potentiom-
eter fully clockwise to the D setting. See Fig. 32.
Table 4 — EconoMi$er IV 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.
†33ZCSENCO2 is an accessory CO
2
sensor.
**33ZCASPCO2 is an accessory aspirator box required for duct-mounted appli-
cations.
††CRCBDIOX005A00 is an accessory that contains both 33ZCSENCO2 and
33ZCASPCO2 accessories.
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$ER IV WITH OUTDOOR AIR
DRY BULB SENSOR
Accessories Required
Outdoor Air
Dry Bulb
None. The outdoor air dry bulb sensor
is factory installed.
Differential
Dry Bulb
CRTEMPSN002A00*
Single Enthalpy HH57AC078
Differential
Enthalpy
HH57AC078
and
CRENTDIF004A00*
CO
2
for DCV
Control using a
Wall-Mounted
CO
2
Sensor
33ZCSENCO2
CO
2
for DCV
Control using a
Duct-Mounted
CO
2
Sensor
33ZCSENCO2†
and
33ZCASPCO2**
OR
CRCBDIOX005A00††
Fig. 32 — EconoMi$er IV 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. 33 — Outdoor Air Temperature
Changeover Set Points