Partial Discharge Survey - Level I

Insulation breakdown begins with a partial breakdown or partial discharge across the surface or inside of the insulation. We use ultrasonic and acoustic emission sensors to detect surface discharges and electromagnetic or transient earth voltage (TEV) sensors to detect internal partial discharge activity. The level I survey is quick and efficient to perform and can rule out good equipment in a very efficient and economical manner. Typically, 90% of the facility’s equipment will be “good”. The other will then need further investigation using Level II equipment. We can detect the condition of your medium voltage equipment including:

• switchgear
• cable terminations
• potential transformers
• current transformers
• control power transformers
• surge arrestors
• bus duct
• switches
• motor control centers
• cast coil transformers
• dry-type transformers

We offer service, equipment sales and training for Level I Partial Discharge surveys.

This bus duct has suffered severe insulation damage and would soon fail completely. Our Level PD I survey program detected this problem and a repair outage was scheduled to complete repairs.

The picture above represents the results of a recent survey that detected a defective surge arrestor. Three different sensor technologies are used to detect insulation problems and Level I surveys can typically rule our 90% of the equipment as “good”. Detailed Level II testing can then to focused on the remaining “suspect” equipment to determine problem location and intensity.