Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
Joey D'Adamo wrote:
Looks pretty unsafe... Funny though, they had overcurrent protection in mind.
They may have had O/C protection in mind but they didn't have it in practice. That breaker is not suitable as service equipment and it might not interrupt a bolted fault. If he had tapped the load side of the main breaker it would "work" electrically but still be illegal.
Originally Posted By: aleleika This post was automatically imported from our archived forum.
Thanks Joseph, for the welcome.
What amazes me about this panel is, it was probably more work to do it this way than doing it correctly. 
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
It is not that big a deal to loosen the lug and slide in another wire. Illegal, but not hard to do. Over at Bob’s house they are talking about splicing methods for hot 4/0 service conductors and they do that up on a ladder as often as not.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
Bolted fault is electrical speak for a dead short. It is like the shorted pieces are bolted together.
In the case of a fault involving service conductors you think of “available fault current” which pretty much assumes the only limiting factor is the resistance of the service conductor itself. That is why 250.66 (sizing the main bonding jumper and ground electrode conductor) is based on service conductor size, not the service amps.
In the case of breakers they have to be service rated which will ensure they have the interrupting capacity to clear that fault. Otherwise it might just arc over and keep conducting until it explodes or something else opens. With this panel I would rather handle that illegal tap than to reset that breaker if it ever tripped. It might just become an arc welder.
, shocking what you might find 