We were asked by a maintenance supervisor if it made sense to infrared scan the bus duct in his manufacturing plant. He suggested it was a waste of time because the conductors in his bus duct were totally enclosed. MIDWEST hears this question a lot. He had a mixture of old bus duct and bus plugs and new. He was especially concerned with the new bus duct and bus plugs because he was adding more and more load and they had a lot of trouble adding some of the new bus plugs because of their location above production machines.
As we have said many times, infrared scanning is the best service possible for finding current related problems in bus duct and attached bus plugs. The Infrared Scanner is so sensitive, it can find warm bus splices and overheating bus plug connections long before they turn into a full blown critical hot connection or arcing failure. This is true for obsolete bus plugs and duct, even when it has been operating for decades without any problem. The real challenge with infrared scanning is when the bus is over production equipment and in very had to see locations. Still, for an experienced Thermographer, these challenges are easily overcome.
So, whether vented or enclosed, feeder or plug in bus duct, Infrared Scanning is the least expensive and most useful maintenance service available.
We were looking for bus plugs and met Orville and Wilber Wright. Well, sort of. MIDWEST was in Dayton, Ohio, looking at old used bus plugs in a former manufacturing facility. A big place. A thousand bus plugs. They had used Square D, ITE, and ITE Bull Dog bus plugs. They had used bus duct and bus plugs throughout the entire facility. We found bus plugs in all the manufacturing areas and above the ceilings in the offices, even the executive office. The facility had evolved and expanded over ten decades. There was a century of history in this manufacturing plant. We found electrical infrastructure every where, behind walls that had been added or moved, above ceilings that had been remodeled many times, hidden in closets, and secreted away in basements long forgotten. We were especially surprised to find a solemn plaque in front of a very old building, a hundred years old that had been beautifully remodeled inside as executive offices. We were looking at old electrical bus plugs and transformers in an area of the building, walked out the front door to find the plaque that read, in part, “…these buildings were constructed in 1910 and 1911 to house the factory of Wilbur and Orville Wright’s first airplane company, The Wright Company.” Now that’s a paradigm shift. One moment it’s just an old building. A second later it’s the Beginning of Manned Flight. Today we have “Human Spaceflight.” But we also still have bus plugs, some new and some old and some no longer used.
Once in a while, we get very confusing calls. The confusion may be no one’s fault. Just two people talking really fast and not realizing they are discussion totally different things. These calls don’t last long, but they can be pretty funny while they do. For example, in one case the call wasn’t for a used bus plug but for using gold plated bus plugs. The conversation was extremely confusing. The customer was referring to horizontal and vertical mounted bus plugs, surface mounted bus plugs, and cable plug type. They discussed temperature ranges and then morphed into new universal bus plugs, which we never heard of. And we’ve heard of them all. The confusion went on as the customer talked about paralleling and dual stacking. We thought we were on the right track when they spoke of contact resistance and snap in place connection. The whole conversation took less the 90 seconds and was turning into total nonsense. They didn’t have a manufacturer or catalog number, just a verbal description. When they brought up gold plating, we knew their bus plugs were not the same as ours. Because we both were using general words, the specifics that would have tipped us off never came up. A fast conversation between two people talking about totally different things. They were talking about new universal bus plugs and sockets for computer type connections, 30 volt, 1 amp devices. We were thinking of 480 volt, 200, 400, or even 600 amp devices for large power distribution. We call this brain lock. You had to be there.