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Condition assessment on switchgear

Condition assessment provides knowledge about the state of the various components in HV grids. This knowledge contributes to the right decisions regarding maintenance and replacement.

Condition based-maintenance improves the overall performance at a lower cost

Partial discharge (PD) is regarded as the best early warning indicator of insulation degredation in MV & HV assets.

The PD survey reveals and locates faults without service interruption. This is a complex PD survey which captures the PD pattern with it`s waveform and the frequency spectrum of every PD pulse that the fault generates. This provides the complete information regarding the activity so that appropriate measures can be taken


The survey is suitable for any electrical equipment from 3kV to 600kV. 

Source: IEEE 493-1997 (GOLD BOOK)

A PD survey will:

• Reveal insulation weaknesses in MV & HV systems

• Increase reliability in MV & HV assets

• Increase asset longevity

• Increase safety

• Reduce Risk
• Reduce maintenance costs moving from preventive         to condition based-maintenance

Online PD Survey


VLF Withstand test

The purpose of a withstand test is to verify the integrity of the cable under test. If the test cable has a defect severe enough at the withstand test voltage, an electrical tree will initiate and grow in the insulation. Inception of an electrical tree growth are functions of several factors including test voltage, source frequency and amplitude, and the geometry of the defect.

Maintenance test according to;IEEE 400.2-2013         

  • Good insulation will be unaffected

  • Reveals; Production deviations, poor workmanship and aging.

  • Uses sinusoidal, 0.1Hz waveform

  • 30 min test time

  • Up to 30 km cable can be tested

Insulation testing of AC Electric Machinery with High voltage at Very Low Frequency IEEE Std 433-2009

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