Daikin ComfortNet DX7TC Service Instructions Manual page 41

SERVICING
NETWORK TROUBLESHOOTING
The ComfortNet™ system is a fully communicating system,
and thus, constitutes a network. Occasionally the need to
troubleshoot the network may arise. The integrated air
handler control has some on-board tools that may be used to
troubleshoot the network. These tools are: red communications
LED, green receive (Rx) LED, and learn button. Refer to the
Communications Troubleshooting Chart and Air Handler
Diagnostic Codes below for error codes, possible causes and
corrective actions.
LED LED
Status
Off
1 Flash
Red
Communications
LED
2 Flashes
Off
1 Steady
Flash
Green Receive
LED
Rapid
Flashing
On Solid
COMMUNICATIONS TROUBLESHOOTING CHART
Indication Possible Causes
• Normal • None
condition
• Communications • Communications Failure
Failure
• Out-of-box reset • Control power up
• Learn button depressed
• No power • No power to air handler
• Communications • Open fuse
error
• Communications error
• No network • Broken/ disconnected data wire(s)
found
• Air handler is installed as a non-
communicating/ traditional system
• Normal network • Control is "talking" on network as
traffic expected
• Data 1/ Data 2 • Data 1 and data 2 wires reversed
miss-wire at air handler, thermostat, or
ComfortNet™ compatible outdoor
AC/HP
• Short between data 1 and data 2
wires
• Short between data 1 or data 2
wires and R (24VAC) or C (24VAC
common)
• Red communications LED – Indicates the status of the
network. The table below indicates the LED status and the
corresponding potential problem.
• Green receive communication LED – Indicates network
traffic. The table below indicates the LED status and the
corresponding potential problem.
• Learn button – Used to reset the network. Depress the button
for approximately 2 seconds to reset the network.
Corrective Action(s)
• None
• Depress Learn Button
• Verify that bus BIAS and TERM
dipswitches are in the ON
position.
• None
• Check fuses and circuit
breakers; replace/reset
• Replace blown fuse
• Check for shorts in low voltage
wiring in air handler/system
• Reset network by depressing
learn button
• Check data 1/ data 2 voltages
• Check communications wiring
(data 1/ data 2 wires)
• Check wire connections at
terminal block
• Verify air handler installation
type (non-communicating/
traditional or communicating)
• Check data 1/ data 2 voltages
• None
• Check communications wiring
(data 1/ data 2 wires)
• Check wire connections at
terminal block
• Check data 1/ data 2 voltages
Notes & Cautions
• None
• Depress once quickly for
a power-up reset
• Depress and hold for 2
seconds for an out-of-box
reset
• None
• Turn power OFF prior to
repair
• Turn power OFF prior to
repair
• Verify wires at terminal
blocks are securely
twisted together prior to
inserting into terminal
block
• Verify data1 and data
voltages as described
above
• None
• Turn power OFF prior to
repair
• Verify wires at terminal
blocks are securely
twisted together prior to
inserting into terminal
block
• Verify data1 and data
voltages as described
above
41