705.12(2)(3) LSIG Breaker Plug & Pickup Values

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cyriousn

Senior Member
Location
ME / CT
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EE & BIM
If an existing main breaker had a 1200A plug, could the pickup values of the breaker be lowered to meet 705.12(2)(3) or would a new, lower rated, sensor plug be required? Seems like the plug would need to be changed as it would limit the max value and prevent anyone from going in at a later date and creating a condition that would overload the bus.
 
I think adjusted settings and appropriate signage would suffice. I'm generally very skeptical of the 'this doesn't meet the code because it's too easy to change' type of argument. Unscrupulous or ignorant people can and will change things. The question is whether you gave fair warning. For example, consider that someone with the wherewithal to replace the plug might also just go ahead and do so, if not given signage to tell them why not.
 
It's ultimately probably a matter of AHJ opinion. Above is my two cents. Consider also that trip settings are considered sufficient in most other cases, as far as I know.
 
Yes, the settings can be changed and then be considered the CB rating for NEC protection under some conditions without changing the plug. The setting of adjustable CBs is covered in NEC 240.6. The adjustable setting can be considered the CB rating only if it meets the restricted access requirements of 240.6(C) to prevent casual adjustment. None of the methods make it impossible to change the setting but they do make it so that it can't easily be changed.
 
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