Located on the south end of Vancouver Island, Victoria General Hospital (VGH) is a 347-bedded acute care facility. The 1981-constructed hospital comprises a main diagnostic and treatment (D&T) podium and two seven-storey patient towers. Over the years, the facility has been expanded and renovated, and includes a new Emergency Department. The hospital is supplied from utility at 25 kilovolts (kV) via an underground feeder into the main electrical room located on Level 1. Much of the original main electrical distribution is still in service. While meticulously maintained, including some breaker upgrades, the equipment is 40 years’ old, and has reached the end of its expected service life.
Examination of the essential power distribution revealed that the two 600-kilowatt, 600-volt generators no longer provide N+1 redundancy. (Both generators are required to meet the demand of the vital and delayed vital branches.) This is a result of the ongoing organic growth of essential power requirements in the facility. The limitation of available essential power poses a significant challenge for routine equipment refreshes, upgrades, and renovations, as most new imaging modalities have a higher power demand than that of the equipment being replaced.
In addition to equipment age and capacity issues, there are two active capital regional district (CRD) trunk water mains — of 1,220 and 1,067 mm in diameter — routed across the site approximately 30 metres from the main electrical room. The site has a natural dip or low point near the main electrical room. If both water supply mains were to rupture due to a natural disaster or piping failure, this electrical room would flood to an elevation of nine metres in 4.5 hours, because there is no automatic control function to shut down water flow.
Electric distribution equipment replacement
Given that the current state of the electrical distribution system is calamitous, Island Health has proactively engaged a consulting team to design the replacement of the existing electrical distribution equipment, and address some of the facility resiliency risk, with a remotely located new electrical energy centre (EEC). The EEC will be located on an elevated greenfield site away from existing structures to mitigate risks, such as flood, fire, and seismic concerns. The design of the new EEC includes capacity to support all existing and anticipated future power requirements at the VGH campus.
The EEC will house BC Hydro service entrance equipment, BC Hydro metering, transformation equipment, generator paralleling and synchronisation controls, dual bypass transfer switches, and the vital, delayed vital, conditional, and normal primary distribution switchboards. It will also contain all the relays and sensors required for protection, control, and monitoring of this new system — both locally and via remote operation from the D&T building’s control room. The new generators will be located in outdoor rated walk-in enclosures adjacent to the EEC. The generator synchronisation bus will be arranged with generator connections, feeder positions, and additional positions for temporary generator, load bank, and future generator connections.
Dual redundant supply
Two utility selectable BC Hydro 25 kV services will replace the single existing service. The dual redundant supply will allow the utility to supply the site from one of two separate substations as required for increased facility resiliency, to upstream outages and eliminate a single point of failure. Two 3-megavolt amperes (MVA) transformers will be used to step down the 25 kV BC Hydro supply to the 12.5 kV distribution in an N+1 configuration. Provisions for replacing these transformers with 5 MVA units have been included in the design for future site demand. Distribution from the EEC to the existing VGH facility and future buildings will be at 12.5 kV.
The new EEC design includes 3 MVA of generator capacity on day one to support the current site peak demand, with N+1 redundancy. Allowances in space, equipment connection locations, and conduits have been made for the installation of additional generators to support future load growth while maintaining N+1 redundancy. 12.5 kV was selected for the generation and site distribution voltage to reduce voltage drop issues and ensure commercial availability of equipment.
Replacement of 40-year-old switchgear
12.5kV feeders and spare conduits will be routed underground from the EEC to the new purpose-built D&T electrical room located adjacent to the D&T building on Level 2, above the potential flood level. Three transformers will further step the power down to 600 V for connection to the new D&T vital, delayed vital, and conditional vital switchboards. These switchboards will reconnect to the existing D&T distribution temporarily. Reconnection of the D&T services has been designed to replace the 40-year-old main distribution switchgear and as many of the existing feeders as practicable.
The benefits of the new EEC are substantial, providing many beyond essential power distribution and natural disaster mitigation. The facility will offer the ability to support all existing normal loads in the hospital, with the conditional branch power for increased flexibility in operations during extended utility outages. The regional laundry facility on site will also be reconfigured to connect to the new EEC conditional distribution, thereby improving service reliability during power outages, and allowing for future electrification of this facility.
It is these combined crucial features that are required for health campuses like VGH to continue to grow and change to meet patient demands. Although the process of replacing the main distribution and essential power equipment in an active hospital can be immensely disruptive and introduce unnecessary risk, this project presents a unique opportunity for Island Health. By combining the necessary replacement of end-of-life equipment with the desired upgrade for future site needs, while optimising project cost and minimising disruptions to operations due to the parallel buildout implementation plan, Island Health will be able to achieve incredibly successful results.
A phased programme
To implement this, Phase 1 will include construction of the new EEC building, the new utility services, the generation plant, and associated commissioning, while Phase 2 will include construction and commissioning of the new D&T electrical room, along with the duct bank connecting it to the EEC.
Phases 3 and 4 are where the benefit of building a new EEC in a separate location, instead of in situ, play a large role in downtime reduction. In Phase 3, essential loads will be supplied from the current generation plant, while the main service supply is migrated from the existing utility service to the new D&T distribution, thereby temporarily supplying the entire site from the new EEC via the old distribution equipment. The existing generators and automatic transfer switches can then be decommissioned to make room for Phase 4 — load migration.
During the load migration phase, new feeders will be installed from the new D&T distribution to the existing sub-electrical rooms prior to numerous controlled outages. Each load will be migrated to a new breaker in the corresponding 600 V power branch in the new D&T electrical room. This phase will require meticulous planning and coordination with facility maintenance and operations staff, as well as clinicians. The resulting power interruptions will be short in duration, and will only impact small areas at a time, making the disruption much easier to manage.
Once all loads have been migrated, the remaining 40-year-old distribution equipment can be removed, and the existing main electrical room on Level 1 can be repurposed. The new EEC project is currently in the design development stage, and will proceed to contract documents pending funding approvals.
Lisanne Naeth
Lisanne Naeth, P.Eng, is a senior electrical engineer at AES Engineering, based at the company’s Victoria office in British Columbia. She specialises in healthcare facilities, and is the lead electrical engineer for the Victoria General Hospital electrical energy centre project. AES Engineering is ‘a dedicated team of electrical engineers, lighting designers, artists, and specialists focused on designing integrated power, lighting, and technology systems for buildings and infrastructure’, with offices in British Columbia and Alberta in Canada.
Acknowledgment
This article, titled, ‘An electrifying opportunity’ / ‘Une opportunité électrisante’, was originally published in the Summer 2023 issue of Canadian Healthcare Facilities, the official journal of the Canadian Healthcare Engineering Society (CHES). HEJ would like to thank the author, CHES, and the magazine’s publisher, MediaEdge, for allowing its reproduction in slightly edited form here.