Carrier 50TCA04-A07 User Manual

Page 35

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35

and D. See Fig. 59 for the corresponding temperature

changeover values.

C06034

Fig. 58 -- 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. 59 -- 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. 60 -- 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. 61.) Wiring is

provided in the EconoMi$er IV wiring harness. (See Fig.

52.)

ECONOMI$ERIV

ECONOMI$ERIV
CONTROLLER

GROMMET

RETURN AIR
SENSOR

RETURN DUCT
(FIELD-PROVIDED)

C07085

Fig. 61 -- 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.

58.)
Outdoor Enthalpy Changeover
For enthalpy control, accessory enthalpy sensor (part

number HH57AC078) is required. Replace the standard

outdoor dry bulb temperature sensor with the accessory

enthalpy sensor in the same mounting location. (See 56.)

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. 62.) The

factory-installed 620-ohm jumper must be in place across

terminals S

R

and SR+ on the EconoMi$er IV controller.

(See Fig. 52 and 63.)

50TC

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