1. General Information

• Part Number: 0-52850 (52850)

• Manufacturer: Reliance Electric (Rockwell Automation / Baldor-Reliance / ABB)

• Product Type: IRFA Interface & Regulator PCB Board (Drive Control Card)

• Application: FlexPak / CardPak Series DC Drives, servo & regulator control interface

• Status: Obsolete / Discontinued; refurbished & surplus units available

• Mounting: Standard plug-in backplane edge connector (VME-style rack)

2. Electrical Specifications

• Logic Supply: 24 VDC (drive internal control power)

• Signal I/O: Analog speed/torque feedback, reference voltage, fault logic, test pulse I/O

• On-board Components:

  • 1 × Test Pulse pushbutton (faceplate)

  • 1 × potentiometer (calibration)

  • 3 × resistor networks, multiple ceramic/polyester capacitors

  • 25+ ICs, 7 transistors, multiple test points (TP)

• Isolation: Opto-isolated inputs for noise immunity

• Protection: Overvoltage, overcurrent, surge & short-circuit protection

3. Key Functions

1. IRFA Interface: Isolation & signal conditioning between drive and controller

2. Regulator Control: Precision speed/torque loop regulation for DC motors

3. Test Pulse Generation: Manual test signal output via front pushbutton

4. Fault Monitoring & Interlock: System fault detection & logic interlock

5. Signal Calibration: Onboard potentiometer for reference gain adjustment

4. Mechanical Characteristics

• Form Factor: Standard CardPak plug-in PCB

• Dimensions: Approx. 190 × 120 × 30 mm

• Connection: Rear gold-finger edge connector; 2 faceplate mounting screws

• Faceplate: “Test Pulse” button, part number, Reliance logo

• Weight: ~0.45 kg

• Coating: Conformal coated (dust, moisture & corrosion resistance)

5. Environmental Ratings

• Operating Temp: 0°C to +55°C

• Storage Temp: -20°C to +70°C

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

• Vibration: 10–100 Hz, 0.15 mm amplitude (industrial standard)

6. Installation & Replacement

1. Power OFF: Disconnect all drive main & control power

2. Insert Card: Align edge connector, seat firmly into backplane slot

3. Secure Faceplate: Fasten 2 screws to rack front panel

4. No Rewiring: Direct pin-compatible swap; no parameter changes required

5. Power ON: Calibrate potentiometer, verify Test Pulse & fault logic

7. Troubleshooting

• No Test Pulse: Check 24 VDC supply, pushbutton, or onboard logic

• Unstable Regulation: Adjust potentiometer; inspect feedback signal wiring

• Faults Persist: Check ICs, transistors, or edge connector contacts

• No Power to Card: Verify backplane 24 VDC and connector seating

8. Compatibility

• Drives: FlexPak 3000, FlexPak Plus, CardPak DC Drive Chassis

• Interchangeability: Pin-compatible with other 0-528xx series control cards

• Wiring: Same pinout as original; no program modifications needed