Linamar, headquartered in Guelph, a small city just west of Toronto, is a multibillion dollar corporation and the second largest auto-parts maker in Canada. Linamar’s focus is precision machining and among its many products are the engine blocks for the Dodge Viper and Chevrolet Corvette.
Keeping the 25 facilities in Guelph up and running safely and efficiently is one of the responsibilities of the 38-member team under Leigh Copp, Engineering and Business Unit Manager for Linamar’s Advanced Systems Group.
Copp’s team recently completed a project to reduce the risk of arc flash from incident energy at one of Linamar’s facilities. Standard switch gear and vented panels weren’t arc resistant and thus posed a significant risk to safety. "That’s 5 times the old Category 4 boundaries so there is no PPE available," Copp said.
Like a grenade in electrical panel
In one event signaling the problem, a seal had failed in an outdoor panel and rainwater dripped into the enclosure, gradually filled it up until the bus bar failed and blew apart. "It was outdoors and nobody was around but it literally was no different than if I’d put a hand grenade inside the panel," Copp said.
His team analyzed the system and learned that the high-incident energy potential was well above what was considered high risk. Indeed it was between 190-212 calories per square centimeter – well above the acceptable safety threshold for the heaviest class of PPE typically available.
Copp and his team designed and installed a high-voltage protection system around the feeder lines coming into the plant. Those 13,800 kV feeders from the local utility now go through a standard high-voltage 15 kV fuse before going into the transformer. Current limiting fuses respond in one quarter of a cycle – before fault current can build to a dangerous level.
In addition, the fuses have been augmented with a high-speed multiline circuit breaker. The new equipment brings the current levels down to where there is practical PPE available to protect the maintenance workers.
Wireless tools ‘a game changer’
When working among electrical panels in high energy incident areas or working on proactive maintenance like Linamar’s arc flash risk mitigation project, Copp and his team deploy the latest wireless test tools. He calls these the connected tools "a game changer" when it comes to high voltage work because it removes technicians from dangerous areas and provides real-time data.
For example, three-phase motors used throughout the facility can be monitored while in use after hooking up wireless clamp meters.
"So I would put the instruments on, close the door, start the machine up, link them to my phone and then go around to the front of the machine and actually monitor the voltage and current while the machine’s operating with the door’s closed completely safely."