Yep, I found it on the squared website, they say there are only a few documented problems and a replacement part kit is available if wanted, but it is not required.
The problem occurs when the breaker is tested outside the cubical and connected to a copper bar that's 1/2" thick, which is too much. The SquareD instructions specify the maximum bar thickness for connecting to the stabs.
My local Square D rep confirmed this issue was the result of failure of the operator to read the instructions. The "enhancement" is to further idiot-proof the design.
Found out there was a "Batch" identified with defective clusters, the end users of these have aparantly been notified. Then again I talked to 3 different Square D guys this week and got 3 different versions, but this one seemed the most creditable.
RAF7 states :"The problem occurs when the breaker is tested outside the cubical and connected to a copper bar that's 1/2" thick, which is too much. The SquareD instructions specify the maximum bar thickness for connecting to the stabs....."
RAF7, when you get a chance, please point me to the instruction book section outlining correct stab thickness for primary injection testing of Masterpack breakers. I just can't seem to find it.
Like I said the story I got was that there was a batch of breakers with a known problem and the owners have been notified, thats the letter I want to see.
Read between the lines, 0.04% have been reported, sounds small but how would one know they have a problem unless the clips failed?? You wouldnt, it is not like these breakers are being racked in and out often either, most industrial plants they are hardly ever touched.
Lets say you have a double ended substation with 20 of these breakers, there is a .8% chance you have a known problem, now lets say your large industrial plant has 14 of these substations, 11.2% chance you have a known problem, and again thats only because either the clips failed or you were notified by the manufacture about a known problem with the clips.
