Bus Plugs Blog – Expert Safety and Usage Information

Square D PQ3206 Bus Plug

It is not unusual for MIDWEST to get a call because a company is having numerous problems with their old bus plugs. Things go along okay for years and then one year they have one failure after another. It seems to make no difference who the manufacturer is. They could be old Square D bus plugs, GE General Electric bus plugs, Westinghouse bus plugs, Cutler Hammer bus plugs or ITE bus plugs. The problem seems not to care who the manufacturer is.  When this pattern appears, it is usually because a chronic mechanical or environmental problem has been present for many years and has been getting progressively worse. Soon or later the mechanical problem or contaminate reaches a critical stage and the bus plugs collectively start to fail. Usually the failure seems to be caused by overheating, or by mechanical failure between the bus duct and bus plugs, or by moisture.  The problem isn’t just moisture or dirt. It’s the accumulation of dirt over many years or the presence of moisture over many years. This means there is a chronic condition causing you to replace bus plugs. One typically doesn’t have to suddenly replace Square D bus plugs or replace Cutler Hammer bus plugs because of normal operating conditions. And replacing Westinghouse bus plugs one after the other without addressing the root cause, will not make the problem go away.  So if you find yourself having to repair or replace numerous bus plugs, look for a chronic cause. If you just don’t find something, then look for a recent acute change that would affect all the bus plugs.