This is a Zinsco RQ38, 30 Amp plug-in 2 pole circuit breaker. I believe the only reason this one lasted is because it powered a dryer receptacle in a home with a gas dryer, and was never used. It's 3/4" wide. (It's got "IQ65" stamped in a small emblem on the side; possibly the designer's test score?)
How do you like it? Do you have any other candidates for the honor?
[This message has been edited by electure (edited 09-08-2006).]
My vote would have to be FPE Stab-loks. Between the handles being too wide to take the cover off without turning some of them off by accident, they were prone to just falling out of the panel if you did take the cover off.
#124267 - 09/08/0609:02 PMRe: The Worst Breaker Design Ever?
Geeze, I'm no spark and I know that 2x 50A breakers in a single would (at load) put an unholy amount of heat through the breaker. How on earth could even CH or SD build something to work, let alone Zinsco?
#124272 - 09/10/0604:23 PMRe: The Worst Breaker Design Ever?
Personal experience is a funny thing; that's why we are taught that personal experience has no relationship to what the actual reality may be.
Failure at the buss connection is a good example of this principle. While we all "know" that certain brands are "junk," compare that opinion with my experience over the past five years. (Again, I am only referring to failures where the breaker connects to the buss).
I've encountered this failure in: 1- Sq D "QO" 100 amp 2-pole 1- Zinsco 50 amp 2-pole 2- GE snap-in 20 amp 1-pole
Complicating factors included: - The Sq. D was often run slightly overloaded (say, 108-112 amps); and,
- The GE failures were from a panel where the maintenace guy "cleaned the buss bars" with a wire brush on his Dremel (!!!!).