1. General Information

• Manufacturer: Reliance Electric (Baldor / ABB)

• Part Number: 0-51831-1 (also written as 0518311)

• Alternate P/N: 0-51831-3, 0-51831-7 (CVTH)

• Description: Current-Voltage Transducer Board (CVTB)

• Function: Isolation and scaling of AC current/voltage to isolated DC control signal

• Application: Reliance MaxPak Plus / VS Spindle Drives, industrial AC/DC drive systems

• NSN: 5998-01-217-7536

2. Electrical Ratings

Inputs

• AC Voltage Input: 0–120 VAC, 50/60 Hz

• AC Current Input: 0–5 A AC (via external current transformer CT)

Output

• DC Control Output: 0–10 VDC, isolated, linear

• Output Load: ≤ 10 mA

Power Supply

• Supply Voltage: 115 / 230 VAC, 50/60 Hz

• Power Consumption: 10 W

Isolation

• Input ↔ Output Isolation: 2500 VAC RMS

3. Mechanical & Environmental

• Dimensions (L × W × H): 11.0 × 7.0 × 2.0 in

  (279 × 178 × 51 mm)

• Weight: 1.0 lb (0.45 kg)

• Operating Temperature: 0 °C to +50 °C

• Storage Temperature: -40 °C to +85 °C

• Relative Humidity: 10–90% RH (non-condensing)

• Mounting: Standard 19” rack, card-edge connector

4. Board Components (Typical)

• Isolation Transformers: 2 (current sense, voltage sense)

• Opto-isolators: 4

• Operational Amplifiers: 6

• Trim Potentiometers: 3 (Span, Zero, Gain)

• Screw Terminals: 12 (for inputs, output, power)

5. Performance

• Linearity: ±0.2% of full scale

• Accuracy: ±0.5% at 25 °C

• Response Time: < 100 ms

• Isolation Test Voltage: 2500 VAC, 1 minute

6. Compatibility

• MaxPak Plus VS Spindle Drives

• Reliance DC Drives & AC Vector Drives

• Replacement for: 0-51831-1, 0-51831-3, 0-51831-7