More on the Importance of Proper Torque Settings
Following up on the emailing about the importance of using proper electrical device torque settings, a customer shared his experiences dealing with improperly torqued connections.
We recently installed three new 480V electrical panels with Square D breakers to feed HVAC units for our raised floor.
When load tested with our generators the following month, one of the breakers popped. Little was thought of this until the same one popped again during the next month's load test.
Copper wire gets harder with pressure (like hammering), and the hardest it will ever become is the moment before breaking. After performing thermal scans, we inspected the terminal connections and found many of them over-tightened. Some of the connections were partly broken which means increased resistance. On these terminals, we had to cut the ends off and strip a new connection. The electricians were then instructed to re-torque all connections within the panel. Temperatures at the connection points dropped by 3 to 7 degrees.
After re-torquing the connections, the next month load test went off without a hitch.
We have a new rule in our data center: Proper torque settings will be applied to every electrical connection new and old, as needed.
Imagine if a facility did not have a thermal camera, troubleshooting would be mostly guesswork. How much money would they have spent replacing breakers?
We don't like guesswork either, that's why every branch circuit power whip build by PDU Cables has its device terminals torqued to manufacturer's specification using calibrated tools.