1. General Information

• Manufacturer: Reliance Electric (Baldor‑Reliance / Rockwell Automation)

• Part Number: 0‑51445 (also 0‑51445‑A, 051445)

• Product Type: Emitter Follower Card / Gate Driver Interface Board

• Application: Reliance S3 / ImPak Plus series DC variable speed drives

• Function: Buffers and amplifies control signals; provides isolated gate drive for SCR power bridge; improves drive stability and noise immunity

• Status: Obsolete (OEM discontinued); available as used / refurbished

• Warranty: 6–12 months (refurbished units)

2. Electrical Specifications

• Input Signal: Low‑level logic/analog control signals from main control board

• Output Drive: Isolated SCR gate firing pulses (6‑channel compatible)

• Control Supply: +15 VDC / −15 VDC (from drive power supply board, e.g., 0‑51444)

• Isolation Voltage: 2500 VAC (control‑to‑power isolation)

• Onboard Protection:

  • Fast‑acting fuses

  • Transient voltage suppression (TVS)

  • Overcurrent limiting

• Signal Bandwidth: DC to 10 kHz

• Max Drive Current: 500 mA per channel

3. Physical & Mechanical

• Dimensions (L × W × H): 220 × 35 × 25 mm (8.7 × 1.4 × 1.0 in)

• Weight: Approx. 0.2 kg (0.44 lbs)

• Construction: Long, narrow industrial PCB with conformal coating (dust/moisture resistance)

• Key Components:

  • High‑speed power transistors

  • Opto‑isolators

  • Pulse transformers

  • Surface‑mount resistors/capacitors

• Connection: Edge connector + flying lead wiring to SCR stack

4. Environmental Ratings

• Operating Temperature: 0°C to +50°C (32°F to 122°F)

• Storage Temperature: −20°C to +70°C (−4°F to 158°F)

• Humidity: 5%–95% RH, non‑condensing

• Vibration: Industrial grade (cabinet mounting)

5. Compatibility

• Matched Main Control Board: 0‑51381 series

• Matched Power Supply Board: 0‑51444

• Matched Gate/Trigger Boards: 0‑51419, 0‑51422, 0‑51423

• Drive Models: S3, ImPak Plus, VS series DC drives

6. Installation Notes

1. Disconnect all AC/DC power before installation or service.

2. Mount board in designated drive slot; secure flying leads to SCR gate terminals.

3. Verify control supply voltages (+15 VDC / −15 VDC) are within ±5% tolerance.

4. Check pulse transformer wiring phasing before energizing drive.

5. After installation, test for proper SCR firing and drive rotation direction.