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Can we talk about using the wrong torque settings on breaker panel lugs?
I keep seeing guys on job sites just cranking down panel lugs by feel and calling it good. Maybe it's just me but I think that's sloppy work. I worked on a commercial job in Phoenix last summer where a main lug got torqued too hard and actually cracked the bus bar. That caused an arc fault that took out half the building's power for a day. The manual for that panel said 75 foot-pounds but the guy used a 12-inch impact driver and went way past it. I've been carrying a torque wrench in my bag for two years now and it's saved me from these issues every time. Why risk a callback or worse a fire just to save 30 seconds? Has anyone else had a panel fail because of overtightened lugs?
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anthony1273mo ago
Tight lugs can actually make a panel run hotter too. When you overtighten aluminum lugs especially, you crush the conductor and increase resistance right at that connection point. More resistance means more heat which can soften the insulation over time.
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