NEC tap rules

[LenB]

Does anyone know the engineering/technical reasons for, or historical evolution of, the NEC 10ft, 25ft, and unlimited outdoor tap rule as applied to branch circuits, and the tranformer tap rule for 10ft commercial and 25ft industrial. i.e why the specific differences in tap conductor length?

Thanks

 

[DanDel]

I don't think you will find any engineering reasons for the NEC taps rules. These have been around for a long time, and are used to allow a cable connection which is really not protected correctly by limiting its installation parameters to limit the danger of damage.
The longer distances are allowed in applications which have more limiting requirements in overcurrent protection and accessibility.

 

[peebee]

No double-posting allowed on this site. See thread242-44165