Replacement of Utility Circuit Breaker on 200 Amp Transfer Switch 4945-1

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Rawley
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When transferring back to utility power, transfer switch Generac 4945-1 200 amp main breaker trips (when several central AC units are operating from generator power). In trying to replace main utility breaker with identical Siemens unit, cannot get old breaker off of blades to remove.
Have removed single screw in center top of breaker that holds top of breaker onto ATS back panel. Pulling on top of breaker allows the breaker to pull out about 0.5” but then stops and further pressure tends to pull blade mounting from back panel of enclosure.
Any ideas on why breaker is stuck and how to extract will be appreciated.
Chris
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Can you post some images of the switch and breaker?
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Rawley
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Sorry for the delay. I was away from the site.
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grsthegreat
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Theoretically if you .remove the small screw in face of breaker, it will pop right off. Im not sure why it isnt pulling off of tabs. In house panels they pull off easily. This looks like the same breaker as used in standard siemens 200 and 400 amp panels.
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Rawley
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As I indicated, the retaining screw was removed prior to trying to remove the breaker.
Thanks for your reply and help. Any other thoughts would be appreciated.
Chris
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Are the buss bars that connect to the contactor holding you up? It also makes me wonder if there was arcing behind the breaker which is also why it's tripping. If the tabs have been damaged, they may be hanging up or something?
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
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Rawley
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That is my thought that the blades have been damaged by internal arcing but don’t have a way to verify or test the theory. I guess my question is has anyone experienced this in another installation? Any suggestions will be appreciated.
grsthegreat
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In 35 years of electrical ive had to replace many main breakers, but ive never had an issue removing old breaker.

However, i have never had to replace a generac main breaker. Sorry cant help you with that.
Chris
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Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
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