Industrial MP503 Programmable Input Output Controller

The Trane MP503 (MP53 Tracer MP) is a programmable input/output controller for Trane Tracer building automation systems that monitors field devices and provides binary control of HVAC equipment. It communicates over LonTalk networks and integrates with Trane Tracer Summit, Tracker (BMTK), and other LonTalk-compatible building automation systems. The controller provides four universal inputs and four independently controlled relay outputs, supporting input types of 10 kΩ thermistor, 0–20 mA, 0–10 VDC, and dry contact. It is designed to monitor sensors such as temperature, pressure transmitters, current loops, and voltage signals while turning relays for fans, pumps, dampers, compressors, and lighting on or off. Specifications include 24 VAC nominal power (20–30 VAC, 50/60 Hz), panel mounting, and optional metal enclosure (4950-0590); manufacturer part number 4950-0490, and it is commonly deployed in commercial buildings, air handling units, rooftop units, central plants, and energy management systems.