Carrier 50KC04-06 Service And Maintenance Instructions page 33

Table 6 — Thermistor Resistance vs Temperature
Values for Space Temperature Sensor, Supply Air
Temperature Sensor, and Outdoor Air
Temperature Sensor
TEMP (°C) TEMP (°F)
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
SUPPLY
AIR TEMPERATURE
SENSOR MOUNTING
LOCATION
SUPPLY AIR
TEMPERATURE
SENSOR
(SEALED
INSIDE CRIMP
END)
Fig. 49 — Supply Air Sensor Location
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.
Outdoor Air Lockout Sensor
The EconoMi$er IV system is equipped with an ambient tem-
perature lockout switch located in the outdoor airstream which
is used to lock out the compressors below a 42°F (6°C) ambi-
ent temperature. (See Fig. 42.)
ECONOMI$ER IV CONTROL MODES
IMPORTANT: The optional EconoMi$er2 system does not
include a controller. The EconoMi$er2 system is operated by a
4 to 20 mA signal from an existing field-supplied controller.
See Fig. 43 for wiring information.
RESISTANCE
(ohms)
-40 335,651
-31 242,195
-22 176,683
-13 130,243
-4 96,974
5 72,895
14 55,298
23 42,315
32 32,651
41 25,395
50 19,903
59 15,714
68 12,494
77 10,000
86 8,056
95 6,530
104 5,325
113 4,367
122 3,601
131 2,985
140 2,487
149 2,082
158 1,752
Determine the EconoMi$er IV control mode before set up of
the control. Some modes of operation may require different
sensors. The EconoMi$er IV system is supplied from the facto-
ry with a supply-air temperature sensor and an outdoor-air tem-
perature sensor. This allows for operation of the EconoMi$er
IV system with outdoor air dry bulb changeover control. Addi-
tional accessories can be added to allow for different types of
changeover control and operation of the EconoMi$er IV sys-
tem and unit.
Outdoor Dry Bulb Changeover
The standard controller is shipped from the factory configured
for outdoor dry bulb changeover control. The outdoor air and
supply air temperature sensors are included as standard. For
this control mode, the outdoor temperature is compared to an
adjustable set point selected on the control. If the outdoor-air
temperature is above the set point, the EconoMi$er IV system
will adjust the outside air dampers to minimum position. If the
outdoor-air temperature is below the set point, the position of
the outside air dampers will be controlled to provided free
cooling using outdoor air. When in this mode, the LED next to
the free cooling set point potentiometer will be on. The
changeover temperature set point is controlled by the free cool-
ing set point potentiometer located on the control. (See
Fig. 50.) The scale on the potentiometer is A, B, C, and D. See
Fig. 51 for the corresponding temperature changeover values.
LED
LED
LED
Fig. 50 — EconoMi$er IV Controller Potentiometer
and LED Locations
19
LED ON
18
D
17
16 LED OFF
15
14
13
12
11
10
9
50 55
40 45
DEGREES FAHRENHEIT
Fig. 51 — Outside Air Temperature Changeover
33
LED ON
C
LED ON
LED OFF
B
LED ON
LED OFF
LED OFF
60 65 70 75 85 90
80
Set Points
A
100
95