Failure Modes; Communication Link Problems - Trane IntelliPak I Programming, Troubleshooting Manual

Failure Modes

When any condition results in the rooftop unit's inability to perform a normal function,
it is said to have entered a failure mode. There are two types of failure modes.
1.
2. A "Fault recognition by input logic" failure mode.

Communication Link Problems

If one of these messages appear on the Human Interface screen, that Human Interface is
not communicating with the unit.
LOCAL HI COMMUNICATIONS LOSS
CHECK COMM LINK WIRING BETWEEN MODULES
OR
RT-SVP04F-EN
An "Analog input out of range" failure mode.
This failure mode occurs when a sensing device such as a zone temperature sensor
or a humidity sensor begins to transmit information that is outside its allowable
range.
This failure mode occurs when the UCM receives information that does not "make
sense" or does not conform to its predefined logic.
System Testing & Troubleshooting
Used With: All Units with Local HI
Problem: The Unit Mounted (Local)
Human interface has lost
communications with the RTM. See
"Fail Diagnostic" for additional
information.
Check: Wiring between Unit
Mounted (Local) Human Interface
and RTM. Verify crimping and
polarity of communications wiring.
There should be no loose
connections or crimps on wire
insulation.
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