AIS Circuit Breaker Replacement – System Integration Perspective

Existing CB foundation adaptation to accommodate new CB:

- Foundation size, and existing CB fixation anchor bolt position needs to be verified

- Foundation (i.e. pedestal column) verification and testing for strength through rebar locating & digital Schmidt testing to be conducted

- Generally the old generation CBs is heavier and is having larger fixation foot print that current generation. So, there is every possibility that you may require a fixation foot print adaptation in the new CB. Any such Adaptation requirement should be intimated o the CB manufacturer well ahead of delivery schedule. Considering the involvement of forces & moments during CB operation, the CB structural adaptation should be done only and only by the CB manufacturer.

- The existing Marshalling Kiosk foundation to be adapted for new CB

HV connection of New CB to existing flanking equipment:

- In case of pipe / rigid busbar system, please take note of slope / bending requirement for the busbar section between the New CB terminals & adjacent equipment

- There may be a situation where the rigid busbar is welded to the terminals of equipment, flanking the CB. In this case customized HV clamp / connector / adaptation needs to be designed

Adaptation of Control-Monitoring-Interlocking Scheme:

- Adequacy of quantity & size of existing cables needs to be studied. If the breakers to be replaced are pneumatic / hydraulic type then the quantity of existing cables should generally be sufficient for control-monitoring-interlocking scheme of new generation CBs

Adaptation of LV AC & DC power supply:

- Adequacy of quantity & size of existing cables needs to be studied. If the breakers to be replaced are pneumatic / hydraulic type then the size & quantity of existing cables should generally be sufficient for coils, motor, & auxiliary consumption of new CB.

Installation & Commissioning Methodology:

- Planning for decommissioning & un-installation of existing CBs

- Space availability for material handling during site works may pose a serious challenge incase multi-bay shutdown is not permitted by the customer

- Shutdown schedule planning

- Complete substation shutdown planning while connecting ground connections of new CB to substation main Earth-Mat