1. General Information

• Part Number: 528592, 0-52859-2, O528592

• Manufacturer: Reliance Electric (later ABB / Baldor‑Reliance)

• Series: VSDC (Voltage Source DC) Drives, MaxPak, FlexPak, HR2000 Series

• Type: Digital Sequence & Firing Control Board

• Function: Generates precision SCR firing pulses, controls armature/field voltage sequencing, manages drive start/stop, interlocks, and fault coordination for large DC drives

• Status: Obsolete (legacy); refurbished / NOS available

• Mounting: 3U Eurocard for CardPAK rack

  

2. Electrical Specifications

• Backplane Supply: ±15 VDC, +5 VDC (logic), 24 VDC (auxiliary)

• Power Consumption: ≤ 18 W

• Control Processor: Custom digital sequencer + gate array

• Firing Resolution: 12‑bit (0.14° electrical angle)

• SCR Firing Outputs: 6 independent isolated pulse channels (for 3‑phase bridge)

• Pulse Voltage/Current: ±15 VDC, 200 mA peak

• Feedback Inputs:

  • Speed Reference: 0–10 VDC

  • Armature Voltage: 0–10 VDC (scaled)

  • Armature Current: 0–5 VDC (scaled)

• Digital I/O:

  • Inputs: 8×24 VDC (interlocks, enable, run/stop)

  • Outputs: 6×relay/transistor (fault, ready, running)

• Adjustments: Onboard trimpots for Firing Angle Offset, Voltage Calibration, Current Limit, Sequence Timing

• Indicators: Power, Run, Fault, Phase Lock, Firing Pulse LEDs

• Isolation: 2500 VAC (logic to power circuits)

3. Mechanical Specifications

• Form Factor: 3U Eurocard (19” rack)

• Dimensions (W×H×D): 100 mm × 160 mm × 45 mm (with front panel)

• Weight: ~0.75 kg (~1.65 lb)

• Construction:

  • Conformal‑coated industrial PCB

  • Metal front panel with LEDs, trimpots, 20‑pin screw terminal

  • Gold‑finger edge connector (backplane)

4. Environmental Ratings

• Operating Temperature: 0 °C to +55 °C

• Storage Temperature: −20 °C to +70 °C

• Humidity: 10%–90% RH, non‑condensing

• Vibration: 10–100 Hz, 0.15 mm amplitude

• Certifications: UL, CSA, CE (legacy)

5. Key Features

• High‑precision digital SCR firing for 3‑phase DC drives

• Closed‑loop voltage/current regulation with 12‑bit resolution

• Integrated sequence logic: Soft start, field weakening, coast/stop control

• Phase lock monitoring and misfire detection

• Isolated firing pulses for noise immunity and safety

• Front‑panel diagnostics: LED status + calibration pots

• Hot‑swap compatible in standard CardPAK racks

6. Compatibility

• Racks: CardPAK 6‑slot / 12‑slot / 18‑slot

• Drives: VSDC series, MaxPak Plus, HR2000, FlexPak 7000/8000 DC drives

• Interchangeability: 528592 / 0‑52859‑2 fully interchangeable