1. Brand & Model

• Brand: Reliance Electric (now ABB/Baldor)

• Model: 0-52824

• Alias: CLRA Current Loop Regulator Board, Current Control Card, Maxpak DC Drive Board

2. Category

• Category: Industrial Automation Control Board

• Subcategory: Current Loop Regulator (CLRA) Card, Drive System Control Board

3. Basic Information

• Manufacturer: Reliance Electric, USA

• Status: Obsolete (discontinued), only refurbished/used/surplus units available

• Structure: Single PCB with faceplate, 2 front-panel set screws, edge connector for backplane

• Dimensions: 12.25" × 9.75" × 2.5" (approx. 311mm × 248mm × 64mm)

• Marking: Grid pattern (letter/number axis) for component reference; silkscreen "CLRA" and part number

  

  

4. Function & Positioning

• Core Function:

  • Precision current loop regulation for DC drives

  • Gain & rate adjustment via front-panel rotary potentiometers

  • Current limiting & protection for power stages

  • Analog signal processing & closed-loop current control

• Positioning: Key control component for Reliance Maxpak DC drive systems, ensuring stable and accurate current regulation in heavy-duty industrial applications

5. Core Specifications

• Power Supply: 115 VAC, ± auxiliary power

• Controls: 2 rotary dials (Gain, Rate) – 0–10 adjustment range

• Indicators: 3 LED status lights (1, 2, Gain Limit)

• Components: 25+ ICs (NAND, XNOR, op-amps), metal film resistors, ceramic/disk capacitors, transistors, TP test points

• Interface: Edge connector (conductive tabs) for backplane mounting

• Environment: Industrial-grade, ruggedized for harsh conditions

• Mounting: Standard industrial rack (2 faceplate screws)

6. Compatible Accessories

• Rack: Reliance Maxpak DC drive rack systems

• Backplane: Matching edge-connector backplane

• Cabling: Shielded signal cables, 115 VAC power wiring

• Replacement: Compatible ABB/Baldor equivalent current loop regulator cards (check firmware revision)

7. Applications

• Industrial Drives: Reliance Maxpak series DC speed regulators

• Metallurgy: Rolling mills, coilers, uncoilers

• Material Handling: Conveyors, cranes, hoists

• Process Industry: Paper mills, mining, heavy machinery, extruders