200 amp main lugs

Old 06-06-01, 08:48 PM
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Ok guys..I got my 200 amp upgrade done and all went well.
bending the 4/0 alluminum wire wasn't as bad as I thought.
Its inspected and power company turned me back on. I have one question.. How tight should I have made the main breaker
lugs? I was afraid I was going to strip or break them. I have heard war stories about loose mains and heating up??
Inspector said use my own judgement?? any clue?

You guys have been a great help..thanks alot.
Old 06-06-01, 10:36 PM
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In a chart published by Under Writer's Labrotories, the chart calls for 250 inch pounds of torque.

In the NEC 110-3-B says to refer to any torque requirements found in the listing and labling provided by the manufacturer. If nothing is found in the manufacturer's recommendations, then use the chart published by UL above for your wire size mentioned = 250 inch pounds of torque.

The chart mentioned may be found in UL Standard 486B

Most people go by what your inspector said, using what you feel. Remember he is the Authority having jurisdiction.

Good Luck


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