poor man's back up generator

[Chic Rustler]

Not trying to tell you how to run your business bro. But you might want to consider going with a larger diameter wire on those mains. It's apparent they got pretty hot. I see some brown behind and on the sides of them.

here's the old breaker. I'm gonna say loose connection. seen it before with air-conditioners.

 

[wyoDreamer]

Wow

 

[CrealCritter]

here's the old breaker. I'm gonna say loose connection. seen it before with air-conditioners.
View attachment 15551

Yep I would agree with you on your assessment. Heavy loaded (high amperage) appliances need a firm, tight connection to the bus bar. A few times I've heard a buzz come from the panel box. Pulled the buzzing breaker, cleaned it's terminals and pinched them tight with needle nose pliers

here's the old breaker. I'm gonna say loose connection. seen it before with air-conditioners.
View attachment 15551

I would tend to agree with your assessment. Loose or dirty contacts, maybe even not punched down all the way.