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43
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 setpoint selected
on the control. If the outdoor-air temperature is above the
setpoint, the EconoMi$er IV will adjust the outside air
dampers to minimum position. If the outdoor-air
temperature is below the setpoint, the position of the
outside air dampers will be controlled to provided free
cooling using outdoor air. When in this mode, the LED
next to the free cooling setpoint potentiometer will be on.
The changeover temperature setpoint is controlled by the
free cooling setpoint potentiometer located on the control.
See Fig. 50. The scale on the potentiometer is A, B, C,
and D. See Fig. 51 for the corresponding temperature
changeover values.
C06034
Fig. 50
−
EconoMi$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
C06035
Fig. 51
−
Outside Air Temperature Changeover
Setpoints
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)
C06031
Fig. 52
−
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 (p/n: CRTEMPSN002A00). The
accessory sensor must be mounted in the return airstream.
See Fig. 53. Wiring is provided in the EconoMi$er IV
wiring harness.
ECONOMI$ER IV
ECONOMI$ER IV
CONTROLLER
GROMMET
RETURN AIR
SENSOR
RETURN DUCT
(FIELD-PROVIDED)
C07085
Fig. 53
−
Return Air Temperature or Enthalpy Sensor
Mounting Location
In this mode of operation, the outdoor-air temperature is
compared to the return-air temperature and the lower
temperature airstream is used for cooling. When using this
mode of changeover control, turn the enthalpy setpoint
potentiometer fully clockwise to the D setting. See Fig. 50.
Outdoor Enthalpy Changeover
For enthalpy control, accessory enthalpy sensor (p/n:
HH57AC078) is required. Replace the standard outdoor
dry bulb temperature sensor with the accessory enthalpy
sensor in the same mounting location. See Fig. 70. When
the outdoor air enthalpy rises above the outdoor enthalpy
changeover setpoint, the outdoor-air damper moves to its
minimum position. The outdoor enthalpy changeover
setpoint is set with the outdoor enthalpy setpoint
potentiometer on the EconoMi$er IV controller. The
setpoints are A, B, C, and D. See Fig. 51. The
factory- installed 620-ohm jumper must be in place across
terminals S
R
and SR+ on the EconoMi$er IV controller.
Summary of Contents for 50TC*17 Series
Page 39: ...39 C10818 Fig 44 RTU OPEN Control Module...
Page 69: ...69 APPENDIX IV WIRING DIAGRAMS C150370 Fig 58 50TC D30 Control Diagram 208 230 3 60...
Page 70: ...70 APPENDIX IV WIRING DIAGRAMS 5 C150368 Fig 59 50TC D30 Control Diagram 460 575 3 60...
Page 71: ...71 APPENDIX IV WIRING DIAGRAMS C150373 Fig 60 50TC D17 D30 Power Diagram 208 230 3 60...
Page 72: ...72 APPENDIX IV WIRING DIAGRAMS C12399 Fig 61 50TC D17 D30 Power Diagram 460 575 3 60...
Page 77: ...77 APPENDIX IV WIRING DIAGRAMS C12690 Fig 66 50TC PremierLinkt System Control Wiring Diagram...
Page 78: ...78 APPENDIX IV WIRING DIAGRAMS C12691 Fig 67 50TC RTU OPEN Wiring Diagram...
Page 79: ...79 APPENDIX IV WIRING DIAGRAMS C12689A Fig 68 50TC SAV VFD System Control Wiring Diagram...