38
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. 53.) This sensor is factory in
-
stalled. The operating range of temperature measurement is 0°F to
158°F (–18°C to 70°C).
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.
Fig. 53 —
Supply Air Sensor Location
Fig. 54 —
Outside Air Temperature Changeover
Setpoints
OUTDOOR AIR LOCKOUT SENSOR
The EconoMi$er IV system is equipped with an ambient tempera
-
ture lockout switch located in the outdoor airstream which is used
to lock out the compressors below a 42°F (6°C) ambient tempera
-
ture. (See Fig. 45.)
ECONOMI$ER IV CONTROL MODES
Determine the EconoMi$er IV control mode before set up of the
control. Some modes of operation may require different sensors.
(See Table 10.) The EconoMi$er IV system is supplied from the
factory with a supply-air temperature sensor and an outdoor-air
temperature sensor. This allows for operation of the EconoMi$er
IV system with outdoor air dry bulb changeover control. Addition
-
al accessories can be added to allow for different types of change
-
over control and operation of the EconoMi$er IV system 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 setpoint, the EconoMi$er IV system will adjust the out
-
side air dampers to minimum position. If the outdoor-air tempera
-
ture is below the setpoint, the position of the outside air dampers
will be controlled to provided free cooling using outdoor air.
When in this mode, the LED next to the free cooling setpoint po
-
tentiometer will be on. The changeover temperature setpoint is
controlled by the free cooling setpoint potentiometer located on
the control. (See Fig. 54 and Fig. 55.) The scale on the potentiom
-
eter is A, B, C, and D. See Fig. 56 for the corresponding tempera
-
ture changeover values.
Fig. 55 —
EconoMi$er IV Controller Potentiometer
and LED Locations
Fig. 56 —
Outdoor-Air Damper Leakage
DIFFERENTIAL DRY BULB CONTROL
For differential dry bulb control, the standard outdoor dry bulb
sensor is used in conjunction with an additional accessory dry bulb
sensor (part number CRTEMPSN002A00). The accessory sensor
must be mounted in the return airstream. (See Fig. 57.) Wiring is
provided in the EconoMi$er IV wiring harness.
In this mode of operation, the outdoor-air temperature is compared
to the return-air temperature and the lower temperature airstream
is used for cooling. When using this mode of changeover control,
IMPORTANT: The optional EconoMi$er2 system does not in
-
clude a controller. The EconoMi$er2 system is operated by a 4 to
20 mA signal from an existing field-supplied controller. See
Fig. 47 for wiring information.
SUPPLY
AIR TEMPERATURE
SENSOR MOUNTING
LOCATION
SUPPLY AIR
TEMPERATURE
SENSOR
(SEALED
INSIDE CRIMP
END)
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
0
5
10
15
20
25
30
0.13
0.20
0.22
0.25
0.30
0.35
0.40
0.45
0.50
STATIC PRESSURE (in. wg)
FLOW
IN
CUBIC
FEET
PER
MINUTE
(cfm)
Summary of Contents for WeatherMaker 50TC 17-30 Series
Page 34: ...34 Fig 48 RTU Open Overlay for Economizer Wiring ...
Page 35: ...35 Fig 49 VFD Overlay for W2770 Controller Wiring ...
Page 80: ...80 Fig C 50TC 17 28 Control Wiring Diagram APPENDIX D WIRING DIAGRAMS ...
Page 81: ...81 Fig D 50TC 30 Control Wiring Diagram 208 230 3 60 Units APPENDIX D WIRING DIAGRAMS ...
Page 82: ...82 Fig E 50TC 30 Control Wiring Diagram 460 3 60 575 3 60 Units APPENDIX D WIRING DIAGRAMS ...
Page 83: ...83 Fig F 50TC 17 30 Power Wiring Diagram 208 230 3 60 Units APPENDIX D WIRING DIAGRAMS ...
Page 84: ...84 Fig G 50TC 17 30 Power Wiring Diagram 460 3 60 575 3 60 Units APPENDIX D WIRING DIAGRAMS ...
Page 89: ...89 Fig L 50TC PremierLink System Wiring Diagram APPENDIX D WIRING DIAGRAMS ...
Page 90: ...90 Fig M 50TC RTU Open Wiring Diagram APPENDIX D WIRING DIAGRAMS ...
Page 91: ...91 Fig N 50TC SAV VFD System Wiring Diagram APPENDIX D WIRING DIAGRAMS ...
Page 93: ......
