Date: 2025 05-May 28

Eaton Medium Voltage Equipment Liability Training

Overview

Medium voltage (MV)

• vacuum clad circuit breakers
• switchgear
• motor control

Disclaimer: These are cursory, non-exhaustive notes, with gaps in the subject matter and the syllabus.

Interrupter Switch

Mechanical enclosed interrupter switch (MVS)

• A spring drives the speed and force to interrupt the load
• ionized gas is prevented from traveling phase to phase and then phase to ground
  • a flicker blade prevents arcing
• Maintenance is dictated by the number of current interruptions

Medium-voltage inspection keywords:

• Surface tracking
• Corona
• Conductive carbon trails

Materials:

• NORYL

Clean regularly to replace grease which can collect conductive dust (which can create a high resistance conductive opportunity). Use non conductive grease and grease that will not become glue-ish.

Motor control

Medium voltage starters and medium voltage motor control: Ampgard

• Gradual increase to mitigate the risk of in-rush current

Low voltage (LV) components.

Materials

• Glastic: ("Glastic® Grade 1494 is a fiberglass reinforced thermoset polyester material. It is available in sheet form as well as a wide selection of channel, angle, and tube sizes. These materials are the industry standard for flame and arc/track resistant electrical insulation.")