ECN Forum Forums Photo Discussion Forums Photos for General Discussion The Worst Breaker Design Ever?

An update:

As promised in my previous post, I have broken open one of those lovely Zinscrap twins to check out the internals. A few surprises:

1) The mechanism sprang apart as I was separating the cases so unfortunately I can't show the exact layout of the parts;
2) There appears to be a thermal element, but I can't discern any magnetic element for short circuit tripping....hmmmm..maybe that's why these junkers never seem to trip or respond rapidly to a short...;
3) The contacts are tiny, I've seen toggle switches with beefier contacts;
4) Internal clearances are pretty tight;

and the biggest surprise of all:

5) NO INTERNAL COMMON TRIP!! The little metal clip on the external handles is the only link for the two poles.

The one I had actually did have the tiny screw terminals instead of the speaker connectors though.

It also had signs of contact wear (on one pole only) but no heat damage, and the internal lube for the mechanism is still good (but looks and smells like common petroleum jelly or "Vaseline.")

I will send pics with captions as soon as possible, next few days are gonna be busy....

I vote Stablock into worst design due to loose connectionsin almost every panel touched since the original install. And trying to get a new FP100 main is upwards of $300 on a good day for a residential breaker. But Zinsco panels have the worst phase bussings. Tweaked too easily making burn spots on buss and breakers.

As far as Europe is concerned I'd vote for these!
Schrack HLS, the Austrian equivalent of the infamous Zinsco No-Trip breakers!


At least the ones in this panel refused to trip on dead shorts in 2 out of 3 cases until the 20A slow fuse ahead of the fast 10A breaker blew.

Mechanically they're extremely sturdy, with porcelaine bases. One was lacking the "Off" button though... pretty ugly if you had to turn it off fast.
That's 1960s stuff, one row is hots, the other is neutrals.

edited for size, and to put on ECN server

[This message has been edited by electure (edited 09-23-2006).]

The great Zinscos were even advertised on the inside cover of the Los Angeles City Code book!
from 1974:

Well I guess in that era of poor construction methods, "aluminum wire", and disco, the Zinsco didn't all seem that bad..
Hmmm 10,000AIC, Up from 5000 AIC...

They do not trip anyway, so what good is that value I think when they read in the code where " all breakers shall be of the "trip free" design", they kind of mis-interpreted it!

A.D

[This message has been edited by Rewired (edited 09-24-2006).]