MVC3-CPU-MTR MOTORTRONICS

Model: MVC3-CPU-MTR
Brand: MOTORTRONICS (now Toshiba or Fairford in some lines)
Series: MVC Plus / MVC3
Core Function: Microprocessor-based control and protection board for MV soft starter
Type: CPU module (stacked with main board in assemblies)
Key Specs: Handles thermal modeling, SCR firing control, True RMS power calc, operates in 2.3–7.2 kV or up to 15 kV systems (variant dependent)

Key Technical Specifications

Processor: Microprocessor with dynamic thermal register for motor protection
Functions: Phase angle firing control for SCRs, overload curves (NEMA/UL Class 5–30), learned start curve option
Protection: Retentive thermal memory, true time thermal tracking, phase imbalance, ground fault (optional), RTD inputs (up to 12 optional)
Communication: On-board co-processor for serial/optional protocols (verify per build)
Mounting: Stacked on main power board (MVC3-MB series); part of control assembly
Voltage range: Compatible with 2.3–15 kV MV soft starters (system level)
Operating temperature: Typical -20 to +60 °C enclosure (verify enclosure rating)
Insulation: High voltage isolation via gate drive transformers
Firmware: Non-volatile memory for thermal state (no battery needed); version-specific – read via display or comms
Status: Discontinued by manufacturer; limited spares available

Product Introduction

The MVC3-CPU-MTR sits at the heart of MotorTronics MVC Plus medium voltage soft starters, running the microprocessor logic that ramps voltage/current to the motor while protecting against thermal overloads and faults.

It calculates True RMS power, adjusts SCR firing angles, and maintains a dynamic thermal model that remembers motor heat even after power loss. This board suits pump, fan, conveyor, or crusher applications in 2.3–7.2 kV (or higher) systems where smooth acceleration reduces mechanical stress. Since the MVC3 series is older and discontinued, confirm exact compatibility with your starter’s main board (often MVC3-MB) and firmware via nameplate photo or MotorTronics/GE/Toshiba support before ordering.