In article ,
Martin Angove writes:

The comment I liked was the one which said something along the lines of
"The hospital where I worked had these things, installed in 1933. They
were replaced when the wards were remodelled in 1995".

Those bods don't seem to like their "thermomagnetic breakers". In what
way do their breakers differ from our modern MCBs?

My impression from reading US NG's is that their breakers are
not unknown for burning out, falling to bits, drifting trip
values, etc. which I've never come across with ours. If you
pick the things up in Home Depot and look at them, they just
don't feel anything like the same quality as ours either. The
funny thing is some of them are same manufacturers as the EU
ones, but obviously built to different standards (and possibly
price -- I don't recall how that compared with ours).

Many of their older breakers are thermal only, and don't have
the fast fault current response ours do. I don't know if all
their current breakers have the magnetic trip component.

If you get to go to the US, a stroll through the electrical
section of Home Depot is really quite frightening. However,
you'll find many more things stocked which you won't find
stocked in B&Q and would be special order only from even a
UK electrical wholesaler.

--
Andrew Gabriel