I was / am an electrical engineer for 40 years before retiring, and have
never, ever heard of such a design which is deliberately engineered to
become more sensitive as it gets older. This concept for a circuit breaker
is pure nonsense in my opinion.

Smarty


"RBM" wrote in message
...

"dpb" wrote in message ...
wrote:
...
...breakers are designed to become more sensitive as they age, ...

Have you any reference from a manufacturer that is a design criterion?

Don't say it isn't so, but I've never heard or seen it mentioned in any
literature which one would think would be so if were an actual design
feature.

I just did a search of the entire product brochure for the Square D QO
breaker series and there's no mention of "age" or "aging" or
"sensitivity" throughout.

-

From my empirical information I'd agree that breakers become more
sensitive with age, at least ones that routinely control loads close to
their rated limit, but I've never heard or read that it was by any kind of
design. Just more unsubstantiated blather Haller pulls out of his ass