Learning Page (4kV)

4kV Conversion Renewal Program

The largest program in system renewal is the 4kV conversion program and accounts for over 80% of asset replacements. Infrastructure at 4kV is a part of the legacy system that was first installed in Thunder Bay over 45 years ago. It is now an accepted industry best practice to replace assets at this voltage to maintain an efficient distribution system. Synergy North has implemented an asset management policy that when assets of this voltage reach end of life, they have been upgraded to 12/25kV or removed from service. The benefits include the discontinuance of the operating and maintenance costs for substations. The 4kV conversion program replaces end-of-life infrastructure from the oldest areas of our distribution territory. It also removes 4kV assets from the system and brings legacy equipment up to standards to withstand climate change impacts.

Over the five (5) year forecast period, Synergy North plans to invest in removing all of the 4kV infrastructure including:

• 4kV rated wood poles (approximately 260-280 poles per year)
• Distribution transformers (approximately 225 transformers/year) and;
• One (1) km of underground cable.

Once those assets have been replaced at either 12kV or 25kV, the corresponding eleven station transformers and associated sixty-eight station class breakers can be removed from service.