1. General Information

• Part Number: 0-52808 (52808); variants: 0-52808-1 (OLVB), 0-52808-2 (OLVC), 0-52808-3 (OLVD)

• Manufacturer: Reliance Electric (Rockwell Automation)

• Product Type: OLVA/CLVA Overload & Static Control PCB Board

• Application: Reliance FlexPak / CardPak DC Drives, overload protection & brake control

• Status: Discontinued; refurbished/used available

• Mounting: Plug-in card, standard drive backplane edge connector

2. Electrical Specifications

• Power Supply: 24 VDC logic (drive internal control power)

• Signal Inputs: Overload current feedback, DC bus voltage, brake current (IB)

• Control Outputs: Brake control relay/transistor switch, fault alarm signal

• Switch Rating: S1-2: 24 VDC, 3 A (transistor output)

• Thresholds:

  • DC bus (UDC): >50 V (switch closed)

  • Brake current (IB): >0 A (switch open)

• Protection: Overcurrent, surge, short-circuit protection

• Isolation: Opto-isolated I/O for industrial noise immunity

3. Key Functions

1. Overload Protection: Monitors motor current, triggers alarm/trip on overload

2. Brake Control: Manages dynamic brake; S1-2 closes at UDC>50V, opens during braking

3. Status Indication: 5 front-panel LEDs (power, overload, brake, fault, ready)

4. Reset Function: Manual reset button for fault clearing

5. Signal Conditioning: Filters and isolates feedback signals for drive logic

4. Mechanical Characteristics

• Form Factor: Standard CardPak plug-in PCB (190×120×30 mm)

• Connection: Gold-finger edge connector (rear) + faceplate (front)

• Faceplate: 5 LEDs, 1 reset button, 3 mounting screws

• Weight: ~0.45 kg

• Material: Industrial-grade PCB, conformal coated for 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

1. Power OFF: Disconnect all drive power

2. Access Slot: Open cabinet, locate CardPak slot

3. Insert Card: Align edge connector, seat firmly

4. Secure Faceplate: Fasten 3 screws to front panel

5. Wiring: Connect I/O to drive control terminals

6. Power ON: Test LED status, brake operation, and overload trip

7. Troubleshooting

• No LED Power: Check 24 VDC supply and edge connector contact

• Overload LED On: Verify motor load, current sensor, or board threshold

• Brake Not Working: Check S1-2 wiring, DC bus voltage, or brake coil

• Fault LED On: Inspect board components (caps, transistors, ICs)

8. Compatibility

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

• Replacements: Direct swap with 0-52808-1/2/3 (pin-compatible)

• Wiring: Same pinout as original; no parameter changes required