On Sat, 4 Jun 2005 22:59:52 -0700, "william_b_noble"
wrote:

my house was built in '47, in southern CA - it was a cheap house at the
time, I presume. when I bought it, it had the original breaker panel - that
panel had two breaker assemblies, each contained a single 15 and a single 20
amp breaker with one input (screw terminal) and two output terminals - that
was it - In 47, I suppose they didn't use much juice? anyway, one day the
20 amp side of one of them started to trip at about 6 amps (e.g. when I
turned on my microwave), so I pulled it out (there was no main breaker, and
you couldn't pull the meter either, it wasn't in a socket and still isn't) -
I knew I was in trouble when I took the thing to the local good hardware
store and they looked at it and said "what's that?".
I believe my house was typical of those in this area, although I may be the
only homeowner who here who does his own wiring work today.



Up here in Ontario Canad, MOST houses had fused panels well up into
the early seventies - and some later. Mine has a 200 amp fused panel -
can't remember how many circuits - but it has "pull-outs" with 2 fuses
each - come of which have latched"doors" on them so you have to pull
them to change fuses. These are for "split" circuits or 220 circuits.
Also has 4 "cartridge" pullouts for things like stove, drier, AC, etc.

One advantage to fuses is there are no "nuisance trips". And they are
readilly available anywhere.

Back in the '50s, Pardee Homes built tract houses that used Pushmatics in
the original construction. And they didn't have a main cutoff! The only
way to killthe panel power was to pull the meter head. (I used to own
such a house in San Diego...) And a friend in San Jose had a house with
Pushmatics, but that looked like a re-wire job from probably 40 years ago.
I assume they are fairly common in these areas because the local hardware.
stores carry replacement breakers.

There were several varieties of no-Main panels built, including the
Zinsco "Crowfoot" panel, so named for the odd main busses that looked
like two crows feet branching from the meter socket to the three
breakers on that side. And they need the Q breakers with a screw
input tab on the LINE side, no new ones are being made.

The trick is that by NEC Codes you are limited to six fuses or
breaker poles without a main disconnect in the panel. And the
Crowfoot design got you only one true 240V common-trip breaker in the
middle. The only legal way to add extra circuits is a sub-panel.

These panels are great for billboards or guard houses, but six poles
will be full in no time flat in anything bigger than Ted "UnaBomber"
Kaczynski's one-room tarpaper shack in the woods....

t.