1. General Information

• Part Number: 518315, 0-51831-5, O518315

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

• Series: CardPAK Engineered DC Drives (FlexPak / MinPak / MaxPak compatible)

• Type: CVTU – Current-Voltage Timing Unit (hybrid current/voltage control + timing card)

• Function: Precision current/voltage feedback, adjustable time delay, closed‑loop regulation for DC drive current/voltage control & sequencing

• Status: Obsolete; refurbished / NOS available

• Mounting: Standard 3U Eurocard for CardPAK rack

• Cross‑reference: 518314 (0-51831-4, CVTE, standard range), 518316 (extended range)

2. Electrical Specifications

• Backplane Supply: ±15 VDC (nominal)

• Power Consumption: ≤ 6 W

• Control Outputs:

  • Voltage: 0–10 VDC linear adjustable (closed‑loop regulated)

  • Current: 0–5 VDC (scaled for 0–100% motor current)

• Feedback Modes: Selectable current loop (armature current FB) or voltage loop (armature voltage FB)

• Time Delay Range: 0.5–600 seconds (potentiometer adjustable, extended CVTU range)

• Linearity: ±0.1% of full scale

• Temperature Coefficient: ±50 ppm/°C

• Adjustments: Onboard trimpots for Gain, Offset, Current Limit, Time Constant

• Indicators: Power LED, Fault LED, Current Loop Active LED, Voltage Loop Active LED

• I/O Interface: Edge connector (backplane); front screw terminal header for field wiring

3. Mechanical Specifications

• Form Factor: 3U Eurocard

• Dimensions (W×H×D): 100 mm × 160 mm × 30 mm (approx)

• Weight: ~0.5 kg (~1.1 lb)

• Construction: Conformal coated PCB, industrial grade, metal front panel

• Connector: Edge finger (backplane); front 12‑pin screw terminal header

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, 0.1 mm amplitude (operational)

• Certifications: UL, CSA, CE

5. Key Features

• Dual‑loop control: selectable current or voltage feedback for DC drives

• Precision 0–10 VDC voltage output + 0–5 VDC current signal

• 0.5–600 s adjustable timing for coordinated drive sequencing

• Onboard trimpots for calibration (Gain/Offset/Current Limit/Time)

• Compact 3U Eurocard, fits standard CardPAK racks, hot‑swap capable

• Industrial robustness: conformal coating, wide temp range, vibration resistance

6. Compatibility

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

• Drives: Reliance FlexPak, MinPak, MaxPak DC drive systems

• Interchangeability: 0-51831-5 / 518315 fully interchangeable