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Carrier 48TC*D08 User Manual

Page 48

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48

Outdoor air management functions can be enhanced with

field--installation of these accessory control devices:

Enthalpy control (outdoor air or differential sensors)
Space CO

2

sensor

Outdoor air CO

2

sensor

Field Connections -- Field connections for accessory

sensors and input devices are made the RTU--MP, at plugs

J1, J2, J4, J5, J11 and J20. All field control wiring that

connects to the RTU--MP must be routed through the

raceway built into the corner post as shown in Fig. 36.

The raceway provides the UL required clearance between

high-- and low--voltage wiring. Pass the control wires

through the hole provided in the corner post, then feed the

wires thorough the raceway to the RTU--MP. Connect to

the wires to the removable Phoenix connectors and then

reconnect the connectors to the board.

Space Temperature (SPT) Sensors

A field--supplied Carrier space temperature sensor is

required with the RTU--MP to monitor space temperature.

There are 3 sensors available for this application:

S

33ZCT55SPT, space temperature sensor with override

button

S

33ZCT56SPT, space temperature sensor with override

button and setpoint adjustment

S

33ZCT59SPT, space temperature sensor with LCD

(liquid crystal display) screen, override button, and

setpoint adjustment

Use 20 gauge wire to connect the sensor to the controller.

The wire is suitable for distances of up to 500 ft. Use a

three--conductor shielded cable for the sensor and setpoint

adjustment connections. If the setpoint adjustment

(slidebar) is not required, then an unshielded, 18 or 20

gauge, two--conductor, twisted pair cable may be used.

Connect T--55 — See Fig. 44 for typical T--55 internal

connections. Connect the T--55 SEN terminals to

RTU--MP J20--1 and J20--2. (See Fig. 62.)

SEN

SEN

J20-1

J20-2

C08460

Fig. 62 -- RTU--MP T--55 Sensor Connections

Connect T--56 — See Fig. 46 for T--56 internal

connections. Install a jumper between SEN and SET

terminals as illustrated. Connect T--56 terminals to

RTU--MP J20--1, J20--2 and J20--3 per Fig. 63.

SEN

J20-1

J20-2

SEN

SET

Jumper

J20-3

SET

C08461

Fig. 63 -- RTU--MP T--56 Sensor Connections

Connect T--59 — The T--59 space sensor requires a

separate, isolated power supply of 24 VAC. See Fig. 64

for internal connections at the T--59. Connect the SEN

terminal (BLU) to RTU--MP J20--1. Connect the COM

terminal (BRN) to J20--2. Connect the SET terminal (STO

or BLK) to J20--3.

OR

SET

SEN

OPB

COM- PWR+

BLU (SPT)

BLK (STO)

24 VAC

SENSOR

WIRING

POWER
WIRING

BRN (COM)

NOTE: Must use a separate isolated transformer.

C07132

Fig. 64 -- Space Temperature Sensor Typical Wiring

(33ZCT59SPT)

Economizer controls —

Outdoor Air Enthalpy Control (PNO HH57AC077) --

The enthalpy control (HH57AC077) is available as a

field--installed accessory to be used with the EconoMi$er2

damper system. 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. See below.)

48TC