What causes supply air temperature failure in CCPIII

Issue:

What causes supply air temperature failure in CCPIII

Resolution:

It is possible for the CCP III to have two values for Supply Air temperature, one from the communicating bypass and one from the Voyager rooftop.  If the Supply Air sensor on the Communicating bypass fails, the diagnostic message is "Bypass Duct Temp sensor fail".  This is a priority three diagnostic and can cause a priority shutdown.  If the SA temp sensor on the Voyager fails the diagnostic is "SA temp sensor fail".  This is a priority one diagnostic, the system will continue to run. 

Notes:

If the SA sensor on the communicating bypass fails the CCP will use the Voyager's SA temp as a backup and continue to run.

If the unit does not have an RTOM with SA temp input, it uses the MAT input on the RTEM.  If the MAT sensor has failed, it will cause the bypass duct temp sensor to show as failed.  Troubleshoot the MAT sensor, per Reliatel diagnostics manual.  If failed, replace MAT sensor and unit should return to normal operation after power cycling RTU.

 

Other Question/Problem/Cause Statements:

•  How can I tell where the Supply Air temp failure diagnostic is coming from, the Voyager or the communicating bypass when getting a Supply Air Temp failure on the CCP III
• Where does the Supply Air temp failure diagnostic come from on CCPIII
• What causes supply air temperature failure in CCPIII

Facts:

• Tracker BMTK
• VariTrac III Central Control Panel (CCP)

Original wave: wave653