Model Definition

• 0-52868: Official part number for VSAC (Voltage Sense & Control) Board

• VSAC = Voltage Sense & Control (15–50 HP AC spindle drives)

• Purpose: Voltage monitoring, bus regulation, over/undervoltage fault protection

• Complementary boards: 0-52860-2 (VSAC, low-power), 0-52861 (DCGA), 0-52862 (CLSA)

Technical Specifications

• Board Type: 18D plug-in PCB, edge connector, metal faceplate (2 locking screws)

• Function: DC bus voltage sensing, overvoltage/undervoltage detection, voltage regulation, fault signal generation

• Compatibility: Reliance MaxPak Plus / AutoMax PMI VS spindle drives (15–50 HP)

• Components: Precision voltage dividers, high-voltage op-amps, voltage comparators, fault relay outputs

• Weight: Approx. 0.91 kg (2.0 lbs)

• Status: Discontinued by OEM; NOS/refurbished/used only

Interfaces & Communication

• Edge Connector: Connects to drive rack backplane for DC bus voltage, control power, and fault signaling

• Voltage Input: Direct tap from DC bus (up to 800 VDC)

• Fault Output: Isolated relay contacts for drive interlock and alarm systems

• Isolation: High-voltage isolation between DC bus and control logic

• Fieldbus: None; hardware-based voltage protection only

Key Features

• Dedicated voltage sensing and regulation for 15–50 HP AC spindle drives

• Precision monitoring of DC bus voltage with over/undervoltage trip thresholds

• Fast fault response to protect power semiconductors (IGBTs/SCRs)

• Works with DCGA (firing control) and CLSA (current limit/snubber) boards

• Direct plug-in replacement for VSAC boards in 15–50 HP MaxPak Plus racks

• Industrial-grade components for high-noise, high-vibration environments

Application

• Reliance MaxPak Plus / AutoMax PMI VS spindle drives (15–50 HP)

• CNC machine tool spindle motor control (high-power machining centers)

• Legacy AC drive voltage protection and regulation replacement

• High-power spindle drive systems requiring precise voltage monitoring