Carrier 48TM016-028

The mode jumper should be set to M3 for 4 to 20 mA

output. The factory test jumper should remain on OFF or the

enthalpy sensor will not calculate enthalpy.

ENTHALPY SENSORS AND CONTROL — The enthalpy

control (HH57AC077) is supplied as a field-installed accessory

to be used with the EconoMi$er2 damper control option. The

outdoor air enthalpy sensor is part of the enthalpy control. The

separate field-installed accessory return air enthalpy sensor

(HH57AC078) is required for differential enthalpy control.

NOTE: The enthalpy control must be set to the “D” setting for

differential enthalpy control to work properly.

The enthalpy control receives the indoor and return

enthalpy from the outdoor and return air enthalpy sensors and

provides a dry contact switch input to the PremierLink™

controller. Locate the controller in place of an existing econo-

mizer controller or near the actuator. The mounting plate may

not be needed if existing bracket is used.

A closed contact indicates that outside air is preferred to the

return air. An open contact indicates that the economizer

should remain at minimum position.

Outdoor Air Enthalpy Sensor/Enthalpy Controller

(HH57AC077) — To wire the outdoor air enthalpy sensor,

perform the following (see Fig. 31 and 32):

NOTE: The outdoor air sensor can be removed from the back

of the enthalpy controller and mounted remotely.

1. Use a 4-conductor, 18 or 20 AWG cable to connect the

enthalpy control to the PremierLink controller and power

transformer.

2. Connect the following 4 wires from the wire harness

located in rooftop unit to the enthalpy controller:

a. Connect the BRN wire to the 24 vac terminal (TR1)

on enthalpy control and to pin 1 on 12-pin harness.

b. Connect the RED wire to the 24 vac GND terminal

(TR) on enthalpy sensor and to pin 4 on 12-pin

harness.

c. Connect the GRAY/ORN wire to J4-2 on Premier-

Link controller and to terminal (3) on enthalpy

sensor.

d. Connect the GRAY/RED wire to J4-1 on Premier-

Link controller and to terminal (2) on enthalpy sensor.

NOTE: If installing in a Carrier rooftop, use the two gray wires

provided from the control section to the economizer to connect

PremierLinkcontrollertoterminals2and3onenthalpysensor.

Return Air Enthalpy Sensor — Mount the return-air enthalpy

sensor (HH57AC078) in the return-air duct. The return air

sensor is wired to the enthalpy controller (HH57AC077). The

outdoor enthalpy changeover set point is set at the controller.

To wire the return air enthalpy sensor, perform the follow-

ing (see Fig. 31):

1. Use a 2-conductor, 18 or 20 AWG, twisted pair cable to

connect the return air enthalpy sensor to the enthalpy

controller.

2. At the enthalpy control remove the factory-installed

resistor from the (SR) and (+) terminals.

3. Connect the field-supplied RED wire to (+) spade

connector on the return air enthalpy sensor and the (SR+)

terminal on the enthalpy controller. Connect the BLK

wire to (S) spade connector on the return air enthalpy

sensor and the (SR) terminal on the enthalpy controller.

OPTIONAL ECONOMI$ERIV AND ECONOMI$ER2 —

See Fig. 33 and 34 for EconoMi$erIV component locations.

See Fig. 35 for EconoMi$er2 component locations.

NOTE: These instructions are for installing the optional

EconoMi$erIV and EconoMi$er2 only. Refer to the accessory

EconoMi$erIV or EconoMi$er2 installation instructions when

field installing an EconoMi$erIV or EconoMi$er2 accessory.

To complete installation of the optional EconoMi$erIV, per-

form the following procedure.

1. Remove the EconoMi$erIV hood. Refer to Step 11 — In-

stall Outdoor-Air Hood on page 16 for information on

removing and installing the outdoor-air hood.

2. Relocate outdoor air temperature sensor from shipping

position to operation position on EconoMi$erIV. See

Fig. 33.

3. Reinstall economizer hood.

4. Install all EconoMi$erIV accessories. EconoMi$erIV

wiring is shown in Fig. 36. EconoMi$er2 wiring is shown

in Fig. 37.

IMPORTANT: Failure to relocate the sensor will result in

the EconoMi$erIV not operating properly.

BRACKET

C7400A1004

Fig. 32 — Differential Enthalpy Control,

Sensor and Mounting Plate (33AMKITENT006)

HH57AC077

ENTHALPY

CONTROL AND

OUTDOOR AIR

ENTHALPYSENSOR

HH57AC078 ENTHALPY

SENSOR (USED WITH

ENTHALPYCONTROL

FOR DIFFERENTIAL

ENTHALPYOPERATION)

MOUNTING PLATE

LED

ABC

TR TR1

BRN

RED

GRAY/ORN

GRAY/RED

WIRE HARNESS

IN UNIT

BLK

RED

(RETURN AIR

ENTHALPY

SENSOR)

(OUTDOOR

AIR

ENTHALPY

SENSOR)

ENTHALPY CONTROLLER

NOTES:

1. Remove factory-installed jumper across SR and +before con-

necting wires from return air sensor.

2. Switches shown in high outdoor air enthalpy state. Terminals 2

and 3 close on low outdoor air enthalpy relative to indoor air

enthalpy.

3. Remove sensor mounted on back of control and locate in out-

side airstream.

Fig. 31 — Outdoor and Return Air Sensor Wiring

Connections for Differential Enthalpy Control