Bus Plugs Blog – Expert Safety and Usage Information

During an Infrared Scan, or Thermographic Scan, of the electrical distribution system of a new account, MIDWEST’s Thermographer noted in his report a strange bus plug set up. A 200 amp Cutler Hammer bus plug had a 2 inch pipe installed right in front of the cover. The pipe was 3 inches from the bus plug cover and right near the operating mechanism. The pipe was just kind of hanging there. It didn’t have much support. It went to a huge molding machine near the Square D bus duct. So you couldn’t switch this 200 amp Square D bus plug from the floor and you couldn’t open the cover of the bus plug, if you had to, because of the pipe.  Who in their right mind would do this?  As it turns out, they had an emergency and had to get a temporary line to the molding machine as fast as possible. Apparently the line carried plastic used in the molding machine and this machine was their main money maker. So they just installed pipe temporarily as quickly as possible. And six years later, the temporary pipe was still there. It more or less had become permanent.  Temporary installations evolving into permanent, is not an unusual occurrence. In the real world, production rules.  And like it or not, the same rules that caused a temporary pipe installation, also prevent the permanent installation. In the electrical equipment world, this is somewhat self correcting when the equipment gets unhappy with a bang.  Bus plugs do fail if they are ignored too long.  Whether a GE General Electric, Square D or Cutler Hammer bus plug, it will eventually fail if ignored long enough. When these things happen, those temporary fixes come back to bite you.  

200 Amp PKA36200 Square D Bus Plug For Sale

About the craziest bus plug MIDWEST’s field services have seen was a circuit breaker style bus plug that had the circuit breaker removed and replaced with wire jumpers. Apparently this was done as an extreme emergency temporary fix. It was a 200 amp bus plug. To do this, the entire bus duct must have been turned off, otherwise the jumpers would have had to be installed hot, which would be crazy.  The circuit breaker had been removed and insulated building wire used to connect the line side copper bars, of the 200 amp bus plug, to the feeder cables. The jumpers were connected to the feeder cables using taped up split bolts. The feeder went to the main fused switch for a very large molding machine, so there was fault protection at the machine. But the line side of the main switch could have had an extremely high arc flash hazard level, since the only protection was the main breaker for the entire 1200 amp bus duct. It could have been a Square D bus plug or a Cutler Hammer bus plug. Actually it wasn’t either, but the manufacturer of the bus plug doesn’t make any difference. MIDWEST’s Field Services runs into some of these nightmares now and then. The danger of temporary fixes is they often are forgotten and take on a permanent life within the power system. For temporary repairs, we suggest attaching yellow warning banner ribbon, or other safety measures, until the permanent repairs can be made. In this case though, the temporary fix was too dangerous and should not have been done.

PQ3620G Square D Bus Plug For Sale

Sometimes you couldn’t write the script for the strange things that happen in the real world.  At least in our world of reconditioning old used bus plugs and selling them to folks that tell us they couldn’t tell the difference from new.  The technical world seems so boring to outsiders, but MIDWEST has its share of action. For example, a large food processing facility called at 6:15 PM on a Monday night, in a screaming panic, because they needed a replacement 200 amp bus plug and they needed it right away. They couldn’t get a new one immediately and the electrical suppliers for most of the US were already closed for the day.  The cracking in his voice changed to audible relief when we told him we had a fully reconditioned Square D PQ3620G bus plug, boxed and ready for shipping pickup. It was set to go to another customer, but it was part of an order for over 100 bus plugs and there was no urgency for it to ship. It was a shipping scramble but the food processing plant had their like new Square D bus plug the next morning. What’s the chance MIDWEST would have a Square D PQ3620G bus plug sitting at the shipping dock, ready to go, and someone calls and needs it “right now.”  The answer to that question is that it’s much more common than one would ever guess. It seems improbable, but it happens fairly often. The odds may be higher because of the number of bus plugs, transformers and circuit breakers we ship.  But it’s always a nice thrill for MIDWEST to defy the odds. And it gives the Engineers something to argue about, the odds versus reality.