1. General Information

• Part Number: 0-52808-1 (also 052808-1)

• Manufacturer: Reliance Electric (ABB Baldor‑Reliance)

• Type: OLVB (Overload Line Voltage Board)

• Category: DC Drive Protection & Monitoring PCB (plug‑in card)

• Status: Obsolete / legacy; available as refurbished/used

2. Description

• Rack‑mount plug‑in control board for Reliance MaxPak Plus / V‑Series DC drives

• Conformal coated PCB, gold‑plated edge connector, front‑panel LED indicators and reset button

• Functionally equivalent to 0-52808 (OLVC) with minor component/revision differences

3. Function

• Overload monitoring: Tracks motor armature current; trips on overload

• Line voltage supervision: Monitors 3‑phase input voltage (over/under voltage)

• Phase sequence detection: Verifies correct rotation; trips on reverse phase

• Field loss protection: Monitors field excitation voltage

• Fault indication: Front‑panel LEDs for quick diagnostics; reset button for fault clearing

• Fault relay output: SPDT contact for alarm/trip (120/240 VAC, 5 A)

4. Electrical Specifications

• Power Supply: 115 / 230 VAC (internal drive supply)

• Power Consumption: ≤ 15 VA

• Monitoring Ranges:

  • Armature voltage: 0–500 VDC

  • Field voltage: 0–250 VDC

  • Line voltage: 3‑phase 208–480 VAC

• Isolation: 1500 VAC (signal‑to‑power)

5. Environmental

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

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

• Humidity: 5%–95% (non‑condensing)

6. Mechanical

• Form Factor: Standard 19” rack plug‑in card

• Dimensions (W×H×D): 120 × 220 × 30 mm

• Weight: ~1.2 kg

• Connector: Gold‑plated edge connector (backplane)

7. Compatibility

• Reliance MaxPak Plus DC spindle drives

• Reliance V‑Series DC drives

• Replaces / interchangeable with 0-52808 (OLVC) in most applications

8. Application

• Machine tool spindle drives (CNC lathes, mills)

• Metallurgical rolling mills

• Paper/textile web lines

• General‑purpose DC drive systems requiring voltage/overload protection