The Background.
The client had identified a potential high safety risk (or ‘red risk’) for the site associated with the security & integrity of the 11kV HV Switchboard associated with one of their major product manufacturing facilities on site.
The product building was supplied by a 35-year old 11kV Switchboard which over the years had started to develop faults and had been shutting down production at great cost and loss of product. In addition, the switchboard contained Oil Circuit Breaker (OCB) distribution, transformer feeders & motor starters which supplied key manufacturing plants & services within the site. The insulating oil represented a potential fire risk to site, and also potential loss of supply to the production plants due to the age and potential mal-operation of the OCB’s in service. There was also an environmental risk identified due to the presence of harmful Polychlorinated Biphenyls (PCBs) within the insulating oil, if it ever leaked or spilled on site or during disposal. The HV supply to an additional production facility on site was to be facilitated as part of this project which required an extension to this existing 11kV Switchboard.
The Client
Our client is a global manufacturing organisation with primary production sites operating on a 24/7 basis.
The Solution.
The Booth Welsh (BW) project scope included:
Design and develop a strategy that would allow continued operation of the production facility during the changeover period.
In conjunction with the client’s site Electrical Engineer and production team, develop a strategy to maintain production while changing out the existing 11kV Switchboard.
Develop a switching sequence and plan for the change out. Liaise with new Switchboard manufacturer for Switchboard layout, Switchboard footprint, cable entry, Battery Charging Unit and Remote Operation Panel requirements. Design cable containment system. Liaise, instruct and support the site electrical installation team with changeover of existing supplies, pulling back and jointing of existing incomer cabling, and installation of a temporary
Ring Main Unit (RMU). The solution involved the procurement of a temporary 4-section RMU to accommodate splitting half of the existing 11kV Switchboard to maintain supplies. Supply the new temporary RMU from the left half of the existing 11kV switchboard. Disconnect and pull back left-side Incomer cables in preparation for reconnection. Disconnect existing 4 off transformer feeders supplied from the left half of the existing
switchboard and temporary supply these from the RMU. Isolate, disconnect and pull back left side Incomer cables in preparation for reconnection.
Disconnect and remove the left half of the existing switchboard. Install left half of new 11 kV Switchboard. Joint and connect existing left half Incomer cabling to new Switchboard. Connect existing transformers and ring section of new plant to new left half of the Switchboard.
Power up left half of new Switchboard and associated feeders. Disconnect existing 2 off transformer feeders and Motor Starter on right half of existing switchboard and connect to the temporary supply RMU. Isolate, disconnect and pull back right side Incomer cables in preparation for reconnection. Disconnect and remove the right half of the existing switchboard. Install right half of new 11 kV Switchboard. Joint and connect existing right half Incomer cabling to new Switchboard. Connect existing transformer, Motor starter and ring section of new plant to new right half
of the Switchboard. Power up right half of new Switchboard, associated feeders and motor. Remove temporary RMU.
The Benefits.
Reduce production shutdown window to maintain production targets.
Elimination of the fire risk associated with the oil insulated breakers and the risk of contamination of PCB’s present within the oil insulation.
Increased security & integrity of supply to the site.