Key Electrical Equipment Upgraded at R.H. Saunders GS

March 22, 2017

As part of a much-needed overhaul at the R.H. Saunders Generating Station in Cornwall, Ontario, four station service transformers and equipment ranging from 600-volt switchgear to 600- and 120-volt distribution panels and cables are being replaced and upgraded.

For nearly 60 years, the 1,045 MW plant on the St. Lawrence River, one of two stations that make up the kilometre-long Moses-Saunders Power Dam, has been providing the province with hydroelectric power. Over that span, several transformers and electrical switchgear have helped deliver power. But the years have caught up to some of this equipment. A few of the transformers, for instance, have served the plant since it opened in 1958.

“Some of the equipment has effectively reached end of life,” says Larry Gallinger, Project Trades Management Supervisor at R.H. Saunders GS.

The project began in September 2015 and is ongoing. The equipment supplies electricity to all of R.G. Saunders GS, powering everything from pumps and motors to lighting and heating to all of the auxiliary equipment on site.
Two of the original oil-based transformers have been removed and replaced so far. One new transformer is fully functional and the other is being installed. The new station service transformers are better in any ways.

“These new transformers are dry transformers,” says Gallinger. “They’re lighter, more efficient, and they take away any environmental concerns because they don’t contain oil.”

In addition, the new transformers come with coupled switchgear, which greatly enhances safety by reducing arc flash hazard when performing electrical work throughout the plant.

The R.H. Saunders project is just one of many underway across OPG’s fleet of hydroelectric stations. Earlier this year, crews successfully replaced the last of four transformers at Alexander GS in northwestern Ontario. The oldest of these transformers was 86 years old.