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Circuit Breaker Retrofits

Why take the retrofit option?

When it comes to upgrading or replacing existing switchgear, there are a number of choices faced by the switchgear owner. In some cases the whole switchgear is replaced with new equipment and tested to the latest standards. However, this may be an unnecessary and expensive option when it is actually possible to simply replace the moveable portion of the switchgear which does all the switching work. Most faults are found in this mechanical section and usually only this part is beyond economic repair. In many cases the fixed part is good for another 25 years life as we have seen in many substations with old Reyrolle and Hawker Siddeley and GEC switchgear.

What is the process to determine the state of the switchgear?

Each case must be evaluated on its technical and commercial merits. We can provide a full technical audit of the equipment in your substation and provide a prognosis of the immediate, short-term and long-term dangers if interventions to repair, maintain, refurbish or replacements are not made.

  • Inspection and cleaning of standoff insulators and bushings, new clusters may be required
  • Infrared testing where possible on cable terminations and busbars
  • Partial discharge testing of panels (insulators, bushings..)
  • Torque busbar bolts; ductor testing of breaker in the panel
  • Routine partial discharge testing of retrofits in the factory and ongoing in the substation

As part of a retrofit upgrade we recommend the following upgrades and interventions to lengthen the life of the switchgear:

  • Protection upgrade replace relays
  • Arc fault detection with a (Woodbeam 1S20 Arc Detector.pdf)
  • Fast open-time switches – chicken switches outside sub
  • The installation of an arc-proof front-door so that racking operations may take place in front of a certified arc-proof front door
  • The redesign and implementation of suitable substation ventilation and heating of the equipment to counter humidity and condensation plus other environmental factors
  • The installation of SAW (surface acoustic wave) temperature sensors to provide a visual alarm for a rise in temperature

retrofit2

  • Around 500 Retrofits Installed
  • Many are underground (3000m) in gold mines
  • Not a single switch failure has been reported
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Factory-retrofit-close-up Retrofit-front Retrofit2

 

Brand Racking Type Insulation Medium Ratings Images
AEG Horizontal Oil / SF6 800A, 1250A up to 31,5kA  AEG-630-25KA-SHELL-111-TYPE-VA6312-17
BBC Horizontal SF6 800A, 1250A up to 31,5kA  BBC-TROLLEY
Delle-Alstom – DNF-5 Horizontal SF6 800A, 1250A up to 31,5kA  ISM-TEL-067-DNF-5-design-04
GEC / Alstom SBV-2 Horizontal  Vacuum 800A, 1250A up to 31,5kA  SBV-2-2000A-111-TROLLEY-ASSEMBLY-02
GEC / Alstom SBV-3 Horizontal  Vacuum 800A, 1250A up to 31,5kA  SBV-2-2000A-111-TROLLEY-ASSEMBLY-03
GEC / Alstom SBV-4 Horizontal  Vacuum 800A, 1250A up to 31,5kA  SBV-4-TROLLEY-02
Hawker Siddeley Vertical Oil / Vacuum 800A, 2000A up to 31,5kA Hawker-siddley

Reyrolle LMT

Reyrolle LMS

Reyrolle LMR

 

Vertical

Vertical

Vertical

 

Bulk oil / SF6 

SF6

SF6

630A

630A

630A

LMT-ISM-026-ASM-render