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Outdoor air enthalpy control (pno 33csenthsw) – Carrier 48TC**16 User Manual

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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

Tx

RTU Open is transmitting data over the network segment

DO#

The digital output is active

The

Run and Error LEDs indicate control module and network status

If Run LED shows...

And Error LED shows...

Status is...

2 flashes per second

Off

Normal

2 flashes per second

2 flashes,

alternating with

Run LED

Five minute auto---restart delay after system error

2 flashes per second

3 flashes,

then off

Control module has just been formatted

2 flashes per second

4 flashes,

then pause

Two or more devices on this network have the

same ARC156 network address

2 flashes per second

On

Exec halted after frequent system errors or

control programs halted

5 flashes per second

On

Exec start---up aborted, Boot is running

5 flashes per second

Off

Firmware transfer in progress, Boot is running

7 flashes per second

7 flashes per second, alternating with

Run LED

Ten second recovery period after brownout

14 flashes per second

14 flashes per second,

alternating with Run LED

Brownout

On

On

Failure. Try the following solutions:
S

Turn RTU Open off, then on.

S

Format RTU Open.

S

Download memory to RTU Open.

S

Replace RTU Open.

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.

GRA

BLK

RED

4-20
Main

+ VDC
Out

4-20 Main
Out

+ 24-36
VDC In

LOW

GND

24V

7

PL6-1 (24-V)

PL6-4 (COM)

Outside Air
Enthalpy Switch

Return Air
Enthalpy
Sensor

CTB ECON
(P’LINK: to J4-2) or
(RTU Open: to J2-6)

C11161

Fig. 80 -- Outside and Return Air Enthalpy Sensor

Wiring

48TC

**16