Troubleshooting - Carrier A07049 Installation Instructions Manual

TROUBLESHOOTING

If the display module doesn't power up after power is applied, check the Rc/Rh
and C terminals for 24VAC. If 24VAC is present, check the voltage between Vg
and V+. This voltage will be approximately 12- -20VDC. If voltage is present,
check the polarity to make sure it is wired correctly. The display will not power
up if polarity is reversed.
Error Codes
"- -- -" - - If AC/HP Control cannot properly read room temperature, display will
indicate "- -- -" and all outputs (except fan, if on) will turn off. In the case where
the installer has selected to average the local sensor and the remote room sensor,
the AC/HP display will alternate between "- -- -" for the failed sensor and the
temperature sensed by the working sensor every 10 seconds. The control will
operate from the temperature sensed by the working sensor.
E1 - - If the Display Module and the Equipment Control Module cannot
communicate via two- -wire connection, an E1 will be displayed.
E2 - - There is no E2 error message.
E3 - - If AC/HP Control cannot properly read outdoor temperature, and it is
needed for proper operation, display will indicate "- -- -" in the outdoor
temperature location.
E4 - - If AC/HP Control's internal memory fails, E4 will be displayed. Replace
AC/HP Control.
Table 3 can be used as a troubleshooting tool for determining which outputs will
be active for a particular configuration and each operating mode.
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