Switchgear Commissioning and Maintenance Testing

May 19, 2016 - 2 minutes read
Gabriel Ojeah presenting at SirfRT

Gabriel Ojeah presenting at SirfRT

Gabriel Ojeah made a presentation at the SirfRT on 5 May 2016 on switchgear commissioning and maintenance testing. The following are the key points in his presentation:

Basic Functions of Electrical Switchgear

The basic functions of a switchgear assembly include:

  • Control: Functional switching and emergency switching
  • Protection: Fast isolation of faulted circuits
  • Isolation: Secure physical isolation of downstream circuits for maintenance or other purposes

Purpose of Switchgear Routine Testing

Commissioning tests – verify whether design requirements and other contractual requirements have been satisfied.

The design requirements would include functional requirements and safety requirements. Satisfaction of design requirements would therefore enhance safety of personnel and equipment during the service life of the equipment

Maintenance tests – give an indication of the health of the switchgear during its service life and provide input data for asset management systems

Timing of Switchgear Routine Testing

Commissioning tests are conducted as Factory Acceptance Tests (FAT) at the manufacturing facility, FAT at the assembly facility and Site Acceptance Tests after erection on site, while maintenance tests are conducted during the service life of the switchgear.

HV Switchgear Routine Tests

Switchgear routine tests consist of dielectric test on the main circuit, test on auxiliary and control circuits, measurement of the resistance of the main circuit, partial discharge measurement. These include:

  • Dielectric test on the main circuit
  • Test on auxiliary and control circuits
  • Measurement of the resistance of the main circuit
  • Tightness Check
  • Design and Visual Checks
  • Partial Discharge Measurement
  • Mechanical operation tests
  • Pressure tests of gas-filled compartments
  • Tests of auxiliary devices under adverse conditions
  • Measurement of fluid condition after filling on site
  • Circuit breaker additional tests (Timing test including verification of specified operating sequence, Dynamic contact resistance, Displacement curve)
  • Current Transformers tests (Ratio, Phase deviation, Polarity, Burden, Winding resistance, Loop resistance, Excitation, Insulation resistance, Primary injection)
  • Voltage Transformers tests (Ratio, Phase deviation, Polarity, Burden, Winding resistance, Insulation resistance, Primary injection)
  • Protection Relay tests (Verification of enabled functions through secondary injection
  • Verification of enabled functions through primary injection where required, Protection integration (local tripping and inter-tripping)
  • Online commissioning checks (Phasing Checks, Metering Checks, Protection Relay Data Capture Check)
  • Thermography
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