| MONITOR | 1/2018 32 Recently, the waste water treatment facility under- went substantial upgrades to ensure it stays online and operational 24/7 for years to come. The current upgrades, which were undertaken by 3 Phase Power Systems Inc. focused on replacing seven Variable Frequency Drives (VFDs) (three 1200 hp units for Influent Pumping Station (IPS), and four 684 hp units for Trickling Filter Pumps). The current VFDs, transformers and motors have been in service since 1997 without any major failure; the upgrade is designed to ensure a minimum of 15 addition- al years without failure. With an ever-increasing demand of waste water to treat, high operational availability is paramount both to the plant and the surrounding municipalities that rely on the waste water treatment services provided. The focus of MetroVancouver is to maximize the eco- nomic efficiency of their pumps and filters that play a key role in water treatment while maintaining a strict standard of electrical safety throughout the facility. For them to achieve this, MetroVancouver needs to implement a technology that enables them to monitor the safety level of their electrical systems associated with the plant’s pumps and filters. MetroVancouver specified that they did not want to experience a drive failure in the coming 15 years of operation at this treatment facility. As part of this requirement, it was determined that an unearthed system with insulation monitoring has to be installed. In an unearthed system, there is no connection from TECHNICAL APPLICATION High availability for reliable operation in waste water treatment facilities Unearthed power supply and insulation monitoring ensure electrical safety A waste water treatment facility has an important task in treating waste water from several municipalities. The Annacis IslandWasteWater Treatment Plant in British Columbia is the second largest treatment plant in Canada and has one of the highest levels of process treatment automation in the industry. This waste water treatment facility, maintained by MetroVancouver, treats approximately 175 billion liters of wastewater every year. The plant provides secondary treatment to wastewater for over 1 million residents in 14 municipalities.