Mike Dolt Enterprises
Mike Dolt Enterprises
User: kingpb, Location: SE USA as far as you can go
Asked on: Thursday, March 31, 2011 at 3:30 pm EDT
Answered on: Tuesday, May 14, 2024 at 3:34 am EDT
Question: In the 1999 Code 384-16(D) specifically stated that the total continuous load on any overcurrent device in a panelboard could not be loaded to more then 80% unless (Exception) specifically rated for 100%.What happened to this statement, because in the 2002 when this section changed to 408.16 this was taken out, and it does not appear through the 2008.So, does anybody no where it resides now, I can't seem to find the 80% breaker loading rule.
The 80% breaker loading rule is no longer included in the NEC. However, some AHJs may still require it.The 80% rule was based on the fact that breakers can overheat and trip if they are loaded to their full capacity for an extended period of time. The rule was removed from the NEC because it was determined that the 80% rule was not necessary for safety.If you are concerned about the possibility of your breakers overheating, you can derate them to 80% of their capacity. This can be done by installing a breaker with a lower amperage rating than the circuit it is protecting. Flag for review