I too have used them in commercial Kit's req'ed by design/Spec' of plans. Although, I guess I didn't notice if all the items were under the hoods. And it would make sense as a fire code. But true, also just as effective if done with contactors, I guess.
Thanks for the answers gent's, very informative, as always.
Now that computer controlled one, I mentioned was kind of funny, and maybe some of you will appreciate it. Several years ago, I had to change one shunt trip breaker out that served a server room. As the shunt lead was double lugged I didn't want to pull it out, and drop all the other server rooms that were also connected to the same shunt lead. So I asked around with all the people I was doing the work for, (ya know the geek squad) and no one knew. So in order for me to do it, and not blindly, I needed to know it's operation/purpose. As I could not shut this thing off to change one breaker out of ten, and drop the whole operation. So I start tracking it down, it took almost three hours of digging around in boxes, and gutters to track it down. I find it in a 1 gang box under a desk 3-4 rooms away, with a small $10 relay on it, controlled by a thermostat wire that run out to another box, that was some how controled by a serial cable connected to computer. So I track down all the geeks, and we have a pow wow about it, they have to call some guy in England, and they mumbo jumbo about it. Then they tell me an analogy for what they mumbo jumbo'ed about.
Apparenty, it was a learning experiance for the whole geek squad too. They had some sort of virus software that paged the guy in England in case of a virus, and if he could not shut down the servers due to the virus via the software, he could dial up the modem on that computer on his cell phone, punch in some code, and dropped the whole operation. Pretty neat huh?
In retrospect I thought about it.... The weakest link in the whole operation of this complex network was some 18/2 thermostat wire stapled to the wall, and the cord laid on the floor for a CPU computer sitting under a desk that no one on this side of the world knew what it did.
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Oh iwire, nice call on 645..... An often over-looked and rarley enforced set of codes here. Dare I say it I may have over0looked it before! Goood call!
[This message has been edited by e57 (edited 10-14-2004).]
