Surge supressor

Does the NEC allow surge protectors installed in panels? This does not look right to me. Thanks for any help.



i’d call that a forign object. even if it was designed to be in there, doesn’t mean the panel was desing for it. not to mention the “custom fit”. i’d call it out. but let’s see what more knowlagable folks have to say…have at it boys (or girls)

Some surge arrestors and TVSSs are designed and permitted to be installed inside of the panel enclosure.

Something to look for with SPD types of protection are the installation practices which have a lot to do with performance - not code.
The conductors should be as short as possible and little if any bends in them as possible. If bends in the conductors are necessary, they should be in sweeps (gentle bends), not 90 degree angles.

If you want more info, Google TVSS installations and you can find some very good info. Also the grounding is not as important for these installations as you may have previous been told.

I think the key word here would be “installed” not just stuck in the bottom of the panel and left to it’s own devices. That hot lead looks like a small nudge would bring the surge suppressor in contact with it.