Reliance Electric 57C493 AutoMax 376W Rack-Mount Power Supply Module 100–132VAC

Description

The 57C493​ is a 376W rack-mount power supply module manufactured by Reliance Electric — the venerable industrial automation brand now part of Rockwell Automation — and is the dedicated energy heart of the AutoMax PLC / DCS 5000 control system. It converts 100–132 VAC, 50/60 Hz incoming power into the clean, regulated DC voltages required by every module on the AutoMax backplane: the processor, digital and analog I/O cards, and communication modules .

More than a simple AC/DC converter, the 57C493​ is a fully integrated rack power component. It occupies three slots and must be installed in the leftmost position of a 10-slot or 16-slot AutoMax rack, where its aluminum chassis and integrated heatsink sit in the path of the rack’s airflow . With 1500 VAC input-to-input and 600 VDC output-to-rack isolation, front-panel POWER/FAULT LEDs, a three-position memory-protect key switch, a user-replaceable 250V fuse, and a battery-backup connector, the 57C493​ is built as much for field serviceability as for electrical performance . Although the AutoMax line is discontinued and the 57C493​ is now sourced as a new-surplus or certified-refurbished spare, it remains the fastest, lowest-risk way to keep a legacy AutoMax control system online without a full control-platform migration.

Application Scenarios

Picture a steel mill’s hot-strip rolling line. The drive speeds, roll gaps, and interlock logic are all coordinated by an AutoMax rack mounted in a cabinet on the mill floor — a cabinet that sees 50 °C ambient temperatures, constant vibration, and the electrical noise of dozens of large motor starters. The entire rack draws its logic power from a single 57C493. When an input surge arrives from a contaminated plant supply, the 57C493‘s overvoltage and overcurrent protection circuits trip and the FAULT LED illuminates, isolating the fault before it can damage the expensive processor and I/O modules downstream . The mill’s maintenance team reads the LED, replaces the 250V fuse, and has the line back in production the same shift — no reprogramming, no control-logic changes, no six-figure platform upgrade.

Now imagine a 1990s-era paper machine in a provincial mill, still running profitably on the AutoMax system that was commissioned with it. The original 57C493​ fails after more than two decades of service, and the whole production line goes dark — processor, I/O, and communications all lose power at once. Rather than justify a multi-million-dollar DCS replacement, the plant’s engineers source a tested 57C493​ from a specialist MRO channel. The replacement drops straight into the same three leftmost slots, mates with the existing backplane and wiring, and restores full rack power within an hour. No logic modifications, no requalification, no production lost to a controls migration. For a capital-intensive continuous process, that is the difference between a planned maintenance window and a forced shutdown.

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