Carrier 48TC*D08 appendix Space Temperature SPT Sensors, RTU-MP T-55 Sensor Connections

48TC

Outdoor air management functions can be enhanced with field-installation of these accessory control devices:

Enthalpy control (outdoor air or differential sensors) Space CO2 sensor

Outdoor air CO2 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

Afield-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 J20-1

SEN 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

SEN J20-2

Jumper

SET

SET J20-3

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.

	BRN (COM)
	BLK (STO)	SENSOR
	BLU (SPT)	WIRING
OR SET	SEN
OPB	COM- PWR+
		POWER
	24 VAC	WIRING

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.)

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