Replace the breaker not the panel.
Replace the breaker not the panel.
P. S. I agree with advising customer to consider replacement, not forcing it. Gentle arm twisting OK if critical application. Something that hard to find can slow a place down or shut it down if a main brkr goes out. Depends on how critical steady power is. If not critical, could replace when it finally gives out. $ is a big issue too. Can't always pay for something. If I have a customer spending $ freely on junk, I may push harder than a frugal customer having hard times.
I've run into these recently in an old plant. The panelboard is well designed and well built. With that said a breaker that is as old as these are is more likely to fail than a modern one. In addition, on the larger breakers from this company there is some question as to the instantaneous trip capabilities.
For example on a current project I have one of these panels in a building I am performing and Arc Flash Study on. A 225A breaker from this panel feeds a sub panel. Most modern breakers in the 225A class have adjustable magnetic trip or electronic trip units. The Frank Adams 225A breaker is not adjustable.
If there is a Siemens replacement for this breaker I will certainly suggest replacing the breaker or the entire panel to the owner. We could test this breaker but odds are hitting it with 2250 amps to test the instantaneous would destroy the breaker. This is the reason that we don't typically test breakers smaller than 400A unless they are suspect. They might trip but the trip causes them to fail.
I found this topic while searching for a replacement. I hope that Siemens makes one so that the owner can save some money because I would not trust the safety of my employees to a 40-50 year old untested circuit breaker. The added benefit to the owner will be the adjustable trip setting on the instantaneous. With the right breaker I will be able to reduce the arc flash rating on the down stream panel to level zero.
Of course this is an industrial plant and the solutions are different for industry than they would be for a homeowner.