This Emerson Comfort Alert Diagnostics Module (P/N 543-0012-00) is used to monitor HVAC compressor operation and provide real-time diagnostic information. It offers LED flash codes for system faults such as long run time, low voltage, open circuits, welded contactor, locked rotor, and more. The module improves troubleshooting accuracy and helps diagnose compressor and system issues faster. Compatible with Class 2 control circuits and operates on 24 VAC. Unit is in good pre-owned condition and was removed from a working HVAC system. All pins and terminals are intact. Perfect for HVAC technicians, system rebuilds, replacements, or testing. S2
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