14
N
ETWORK
TROUBLESHOOTING
Communications is achieved by taking the difference between
a positive dc signal and a negative dc signal. The positive dc
signal is termed “data 1” or “1”. Data 1 is positive with respect
to ground (or common). The negative dc signal is termed “data
2” or “2”. Data 2 is negative with respect to ground (or com-
mon).
Data 1 should be approximately 2.8 volts dc. Data 2 should be
approximately 2.2 volts dc. The voltage difference between
data 1 and data 2 should be approximately 0.6 volts dc.
Verify that the bus TERM dipswitches are in the ON position.
1
2
OFF ON
TERM
TERM
The ComfortNet™ system is a fully communicating system,
and thus, constitutes a network. Occasionally the need to
troubleshoot the network may arise. The integrated control
module has some on-board tools that may be used to trouble-
shoot the network. These tools are: red communications LED,
green receive (Rx) LED, and learn button.
•
Red communications LED - Indicates the status of
the network. The table below indicates the LED status
and the corresponding potential problem.
•
Green receive 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.
S
YSTEM
T
ROUBLESHOOTING
NOTE:
Refer to the instructions accompanying the CT
compatible indoor air handler/furnace/modular blower unit for
troubleshooting information.
Refer to the Troubleshooting Chart at the end of this manual for
a listing of possible air conditioner and heat pump error codes,
possible causes and corrective actions.