Trane HUV Installation, Operation And Maintenance Manual page 68

Wired Controllers—Communication Wiring
Transformer Recommendations
A 24Vac power supply must be used for proper operation
of the binary inputs, which requires 24Vac detection. In
addition, the spare 24Vac outputs may be used to power
relays and TRIACS.
• AC transformer requirements: UL listed, Class 2 power
transformer, 24Vac ±15%, device max load 24VA. The
transformer must be sized to provide adequate power
to the controller (12VA) and outputs (maximum 12VA
per binary output).
• CE-compliant installations: The transformer must be
CE marked and SELV compliant per IEC standards.
Wiring Requirements
To ensure proper operation of the UC400 controller, install
the power supply circuit in accordance with the following
guidelines:
• A dedicated power circuit disconnect switch must be
near the controller, easily accessible by the operator,
and marked as the disconnecting device for the
controller.
2
• 18 AWG (0.823 mm ) copper wire is recommended for
the circuit between the transformer and the controller.
Important: The controller must receive AC power from
a dedicated power circuit; failure to comply
may cause the controller to malfunction. DO
NOT run AC power wires in the same wire
bundle with input/output wires; failure to
comply may cause the controller to
malfunction due to electrical noise.
Connecting Wires
To connect the wires:
1. Disconnect power to the transformer.
2. Connect the 24Vac secondary wires from the
transformer to the 24Vac and
UC400 controller (refer to the illustration below).
3. Do one of the following to ensure the controller is
adequately grounded:
• Connect a grounding pigtail at some point along the
secondary wire that runs between the controller
terminal and the transformer.
• Ground one of the
the enclosure (if the enclosure is adequately
grounded) or to an alternate earth ground.
68
terminals on the
terminals on the controller to
.
24Vac
transformer
IM C
24 24 24
VAC VAC VAC
XFRM
AO1 AO2
UI 1
BI 4 BI 5
1
ADDRESS
RELAYS
BO1 BO2 BO3
x1
NO NC C NO NC C NO NC
Power ON Check
To perform a Power ON check:
1. Verify that the 24Vac connector and the chassis ground
are properly wired.
2. Remove the lockout/tagout from the line voltage power
to the electrical cabinet.
3. Energize the transformer to apply power to the UC400
controller.
4. Observe the UC400 controller when power is applied
to verify the power check sequence as follows:
a. The power LED lights red for 1 second
b. The power LED lights green
• If the sequence above is completed as described,
the controller is properly booted and ready for the
application code.
If the power LED flashes red, a fault condition exists.
A pigtail connection may be
necessary between earth ground
and/or enclosure ground if the
device is not grounded through
one leg of the transformer wiring.
Alternate ground method.
+ 24
VDC
BI 1 BI 2 BI 3 LINK IMC
UI 2 AI 1 AI 2 AI 3 AI 4 AI 5
P 1 P 2
LINK IMC
TX
RX
SERVICE TOOL
BO1 BO2 BO3 BO4 BO5 BO6 BO7 BO8 BO9
CONNECT AC POWER TO THE TRAIC SUPPLY TO POWER THE TRIACS
TRIAC SUPPLY TRIACS
C A B B
BO4 BO5 BO6 BO7 BO8 BO9
UV-SVN02C-EN
IM C
SERVI C E
A