AskCodeMan

What code cycle started the retention of back fed breakers, the building I am looking at which done under 1981
Thanks Jerry

There are two answers:
- a) The "safety" related answer is that as soon as the very first circuit breaker was installed back-fed, that installation created a potential electrocution hazard.
- b) The "code" related answer which came about because of the hazards created by people doing the stupid thing in a) and enough people being shocked (and after enough electrocutions?) the 1990 code was the first edition that requirement made it into the code - but keep in mind that the finalized code change would have been done prior to the prior code cycle (i.e., the change would have been made during the time the 1984 NEC was in effect ... and being as most code changes are not approved during their first submission cycle, it is quite possible that the requirement was being considered one - 1981, two - 1978, or possibly three - 1975, code cycles previously).

An example of NEC code change cycles is this: the 2014 NEC has been out almost one year, code changes for the 2017 NEC must be submitted prior to November 7, 2014. After November 7, 2014, any submissions would need to be for the 2020 NEC. That's the two code cycle, six year, difference I am referring to.

The above means that the back-fed breaker hazard was recognized long before the code actually printed the requirement for and additional securing method for plug-in breakers.

However, the safety hazard was created as soon as some person installs a back-fed breaker without a secondary fastening means ... and, yes, I still find those electricians who do that very thing today - even though it is have written and documented in the NEC since the 1990 Edition 14 years ago.

As you can see, whether before or after the code actually contains the written prohibition for that ... electricians did it and still do it.

Thanks Jerry