Re: "Any recommendations that you could make about the companies?"
No, sorry. As I mentioned, the manufacturers all have some documentation of some laboratory tests which "prove" that theirs work better than all others. Field experience is not much help either, as transients are so variable from site to site; it's often hard to tell if you had a good or bad TVSS or if you had a good or bad utility source.
At least one manufacturer heavily promotes individual fusing of each MOV or whatever technology is being used (usually, the protection on each phase is made up of several MOV's in parallel). That makes a LOT of sense, to me anyway. I'd say look for individual fusing.
Metal Oxide Varistors (MOV's) and Silicon Avalanche Diodes (SAD's) are the two most common technologies used. They each have advantages and disadvantages. Some manufacturer's include both -- hey, the more the merrier, if you ask me. At least no-one can say you went for the cheap one that way.
There's various conflicting UL, IEEE, NEMA, and IEC standards. They all seem to measure completely different parameters. Pick the one you like best.
Leviton publishes an "Applications Manual and Reference Guide for Surge Protection and Line Conditioning Products," available in PDF format here:
This is not a recommendation for Leviton, and for all I know this is a completely biased publication (although it seems OK to me). At least it gives you some more detail on some of the considerations I oulined above, and seems to be reasonably logical. They have some other information available here:
Keep in mind that for any TVSS, it's critical to keep the lead lengths as short as possible. That means to get something mounted integral to the equipment if possible. That usually means a TVSS by the same manufacturer. (Next best to integral is to mount the TVSS to the enclosure externally).
My standard is to allow any major mfgr to include their own TVSS with their equipment. Beyond that, I'll accept any well-known TVSS manufacturer. My idea of "well-known TVSS manufacturer" is probably different from the next guys, so I won't even bother listing them here.
As I mentioned, this is voodoo science. It's only a little more scientific than specifying a voodoo doll. You find a voodoo doll you like, buy it. If it works out for you, go back to the same witch docter next time. If not, well, then try a different witch docter. Same thing with TVSS's. Don't worry yourself TOO much about finding the right witch docter or TVSS manufacturer on the first try. Just talk too as many friends as possible about their experiences first (actually, this is about the same way I select my medical docter too).
Hope this helps. Good luck.
