29
Table 4 – LEDs
The LEDs on the RTU Open 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. TS--5580J--01 for complete
configuration of RTU Open operating sequences. Contact
your Bryant applications engineer for details on
configuration and troubleshooting of connected networks.
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. 50.)
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. 50. Connect the
enthalpy control power input terminals to economizer
actuator power leads RED (connect to 24V) and BLK
(connect to GND).
7
CTB ECON
(RTU Open: to J2-6)
LOW
GND
24V
Enthalpy
Switch
GRA
BLK
RED
Factory Wiring Harness
PL6-1 (24-V)
PL6-4 (COM)
C11169
Fig. 50 -- Enthalpy Switch (33CSENTHSW) Connections
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.
558J