The 418285-79A is a MAPS-1 Multi-Channel Power Supply & Control Board manufactured by Reliance Electric (now part of ABB/Baldor). It is a legacy, high-voltage printed circuit board (PCB) designed as a dedicated power supply and control interface for Reliance AutoMax and other high-power drive systems. This board is obsolete and no longer in production; only refurbished, surplus, or used units are available for maintenance and replacement of aging industrial drive equipment.

It is a high-voltage, multi-output power supply PCB engineered for Reliance AutoMax and legacy high-power drives. The board integrates high-voltage transformers, rectifier circuits, voltage regulators, filter capacitors, and fault detection components. Physical dimensions are approximately 250mm × 80mm (long and narrow form factor), with a weight of roughly 0.45kg. It operates from the drive’s 208–480V AC input, providing multiple isolated DC outputs (±15V, 24V DC) for control logic, gate drivers, and auxiliary circuits. Designed for standard industrial temperature ranges (0°C to +60°C), it features high-voltage isolation rated at 3000V AC minimum and includes overvoltage, overcurrent, and short-circuit protection circuits.

The board connects to the drive’s main power input via a two-level terminal strip on the left edge. It interfaces with the drive’s main control board and gate driver boards through two header connectors on the top right edge and several stab-on connectors onboard. Onboard test points and LED indicators (PWR, FAULT) enable status monitoring and troubleshooting. There is no digital communication port; all power and control signals are hardwired with galvanic isolation between high-voltage input and low-voltage output domains. Installation is via slot-mounting in the drive’s power section, secured with nylon spacers at six edge mounting holes.

Its core functions include multi-channel isolated power generation, converting high-voltage AC input into stable, isolated DC outputs for the drive’s control and gate driver circuits. It performs voltage regulation and filtering, ensuring clean and consistent power supply to sensitive electronic components, reducing electrical noise and transient interference. It provides fault detection and protection, monitoring overvoltage, overcurrent, and short-circuit conditions in the power supply and shutting down outputs to prevent damage to downstream components. Additionally, it serves as a central power distribution hub, distributing regulated power to various subsystems within the high-power drive unit.

It is primarily used in Reliance AutoMax series AC/DC high-power drives (75kW–750kW) for industrial motor control. It serves as a replacement part for other legacy Reliance drive models, including GV3000, MaxPak, and FlexPak high-power variants. Common deployment environments include steel mills, paper mills, cement plants, mining operations, and large-scale manufacturing facilities relying on high-power motor drives for production lines. It is essential for maintenance, repair, and retrofit projects of aging Reliance high-power drive systems, ensuring continued operation of critical industrial equipment.

Install the PCB into the designated slot in the drive’s power section, ensuring all mounting holes are aligned and secured with nylon spacers and fasteners. Before powering on, verify all AC power input and DC output wiring connections against the drive’s schematic to avoid reversed or loose connections