Archive for October, 2011

Perfect Square D MA36500 Circuit Breaker an Ornamental Reminder

October 28th, 2011 1 comment
Square D MA36500 Circuit Breakers For Sale at

Square D MA36500 Circuit Breakers For Sale at

On one of MIDWEST’s Switchgear Service Desks is a Square D molded case circuit breaker in mint condition. It just sits there, in a place of honor, as a reminder that appearances may outright lie. It has nothing to do with whether or not the circuit breaker is Square D or a Cutler Hammer HLCG3400 or a GE General Electric TJK436400WL or any other manufacture. It is there as a reminder that you can’t tell the condition of the inside of the breaker, the operating condition, based on the outside appearances. We see breakers that look like junk, but test out perfectly. And, as in this case, we see breakers that look mint and are junk. We used this circuit breaker because it looks like it is in such great condition. Looks great, opening and closing sounds right and feels right.  But, when we removed the cover, the contacts were what we call, and this is a technical term, fried. Moveable and stationary, main and operating contacts were burned, brown, and blasted. The inside of the arc dividers were charred. The breaker was fatally damaged and could not be used. But it looked in mint condition.  This is a great training aid and we kept it just for that reason.  There is a tendency to make technical judgments based on appearances. This is human nature. But is does not apply to the technical world and it certainly does not apply to the electrical switchgear world.  We’ll call this, “Breaker fallacy number one.”