Carrier 48TC**16 Outdoor Air Enthalpy Control PNO 33CSENTHSW, LEDs, Differential Enthalpy Control

Table 9 – LEDs

The LEDs on the RTU Open Control Board (see Fig. 65) show the status of certain functions:

If this LED is on...		Status is...
Power		RTU Open has power
Rx		RTU Open is receiving data from the network segment
		RTU Open is transmitting data over the network segment
Tx
		The digital output is active
DO#
	The Run and Error LEDs indicate control module and network status

If Run LED shows...	And Error LED shows...
2 flashes per second	Off
2 flashes per second	2 flashes,
	alternating with Run LED
2 flashes per second	3 flashes,
	then off
2 flashes per second	4 flashes,
	then pause
2 flashes per second	On
5 flashes per second	On
5 flashes per second	Off
7 flashes per second	7 flashes per second, alternating with
	Run LED
14 flashes per second	14 flashes per second,
	alternating with Run LED
On	On

Status is...

Normal

Five minute auto---restart delay after system error

Control module has just been formatted

Two or more devices on this network have the same ARC156 network address

Exec halted after frequent system errors or control programs halted

Exec start---up aborted, Boot is running Firmware transfer in progress, Boot is running

Ten second recovery period after brownout

Brownout

Failure. Try the following solutions:

STurn RTU Open off, then on. S Format RTU Open.

S Download memory to RTU Open. S Replace RTU Open.

48TC**16

NOTE: Refer to Catalog No. 48-50HCTQ-01T for complete configuration of RTU Open, operating sequences and troubleshooting information. Refer to RTU Open Controller Integration Guide (Catalog No. 11-808-428-01) for details on configuration and troubleshooting of connected networks. Have a copy of these manuals available at unit start-up.

Outdoor Air Enthalpy Control (PNO 33CSENTHSW)

The enthalpy control (33CSENTHSW) 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 (33CSENTSEN) is required for differential enthalpy control. See Fig. 80.)

Locate the enthalpy control in the economizer next to the Actuator Motor. Locate two GRA leads in the factory harness and connect the gray lead labeled “ESL” to the terminal labeled “LOW”. See Fig. 80. Connect the enthalpy control power input terminals to economizer actuator power leads RED (connect to 24V) and BLK (connect to GND).

The outdoor enthalpy changeover setpoint is set at the enthalpy controller.

Differential Enthalpy Control —

Differential enthalpy control is provided by sensing and comparing the outside air and return air enthalpy conditions. Install the outdoor air enthalpy control as described above. Add and install a return air enthalpy sensor.

Return Air Enthalpy Sensor —

Mount the return-air enthalpy sensor (33CSENTSEN) in the return-air section of the economizer. The return air sensor is wired to the enthalpy controller (33CSENTHSW). See Fig. 80.

	– 4-20	24V	RED		PL6-1 (24-V)
	Main	GND	BLK		PL6-4 (COM)
	+ VDC
					CTB ECON
	Out	LOW	GRA	7
					(P’LINK: to J4-2) or
					(RTU Open: to J2-6)
	Outside Air
	Enthalpy Switch
+ 24-36			Return Air
	VDC In		Enthalpy
	– 4-20 Main		Sensor
	Out
					C11161

Fig. 80 - Outside and Return Air Enthalpy Sensor

Wiring

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