Outdoor Air Enthalpy Control; Differential Enthalpy Control; Return Air Enthalpy Sensor - Bryant 549J Series Installation Instructions Manual

The LEDs on the RTU Open Controller show the status of certain functions
If this LED is on...
Power
Rx
Tx
BO#
If Run LED shows...
2 flashes per second
2 flashes per second
2 flashes per second
2 flashes per second
2 flashes per second
5 flashes per second
5 flashes per second
7 flashes per second
14 flashes per second
On

Outdoor Air Enthalpy Control

(P/N 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. 59.)
Enthalpy
Switch
24V RED
GND BLK
LOW GRA
Factory Wiring Harness
Fig. 59 - - Enthalpy Switch (33CSENTHSW) Connections
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. 59. Connect the
enthalpy control power input terminals to economizer
actuator power leads RED (connect to 24V) and BLK
(connect to GND).
Status is...
The RTU Open controller has power
The RTU Open controller is receiving data from the network segment
The RTU Open controller is transmitting data over the network segment
The binary output is active
The Run and Error LEDs indicate control module and network status
And Error LED shows...
Off
2 flashes, alternating with Run LED
3 flashes, then off
4 flashes, then pause
On
On
Off
7 flashes per second, alternating
with Run LED
14 flashes per second,
alternating with Run LED
On
PL6-1 (24-V)
PL6-4 (COM)
CTB ECON
7
(RTU Open: to J2-6)
Table 24 – LEDs
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 MSTP 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:
S Turn the RTU Open controller off, then on.
S Format the RTU Open controller.
S Download memory to the RTU Open controller.
S Replace the RTU Open controller.
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
(33CSENTHSW). See Fig. 60.
– 4-20
Main
+ VDC
Out
C11169
Outside Air
Enthalpy Switch
+ 24-36
VDC In
– 4-20 Main
Out
Fig. 60 - - Outside and Return Air Enthalpy Sensor
47
wired to the enthalpy
24V RED
GND BLK
LOW GRA 7
Return Air
Enthalpy
Sensor
Wiring
controller
PL6-1 (24-V)
PL6-4 (COM)
CTB ECON
(RTU Open: to J2-6)
C11170