Technical > Home Improvement > GE breaker experts?

reply to SmokChsr

Re: GE breaker experts?

reply to SmokChsr
The moral of the story is there are still many devices where a circuit breaker is not the ideal form of protection for a device. For other than "life safety" issues (arc fault, ground fault), fuses are still far superior to breakers. The reason breakers are so popular is they help keep things "idiot proof". Most people will not go out and buy a larger breaker if it keeps tripping (although some still do). Whereas with fuses it was pretty easy to cheat the wrong fuse into place. I still go into homes and businesses today where every stinking fuse in the panel will be a 30A.

When it comes to high end equipment, fuses are usually specified as the final (and sometimes first) form of protection. A lot of industrial equipment is fused. Another example is cell sites. Most of the radio equipment is fused. They also fuse the main service as well (before the breaker panel).

To answer your question: the breaker most likely failed because it was being used improperly. It is a machine. Just like a car. If you bought a new car and squealed the tires every single time you started, and slammed on the brakes every time you stopped, it would break down pretty quickly. Same principle here.
--
...because I care.

Insurance companies have a bunch of really, really, really boring people called Actuaries who sit around and look at statistics to decide whether or not the risk of insuring a property is "most likely profitable". Some key things that insurance companies look for and consider high risk (and the numbers don't lie): Aluminum wire, outdated fuse panels, K & T wiring, and unprofessional wiring (major code violations).
They may still insure the property, but raise the premium. On my first house I ever bought, the yearly premium was $200 more because it had a 60A service and fuse box.

There is a common misconception that fuses are inferior to breakers. When it comes to protecting equipment, my stance is that fuses are far superior (we're talking A/C distribution here). They typically don't break down over time. A 50 year old fuse is probably going to function just as well as a brand new fuse. You cannot say the same for breakers.
When a fuse fails, it's going to fail open. You'll be hard pressed to find a fuse that fails closed. You can't say that for breakers (look at Zinsco and Federal Pacific).
--
...because I care.

reply to nunya

reply to whizkid3

There is really only one place I see using both fuses and circuit breakers are advantageous. In high current distribution feeders one can get the coordination and adjustability a breaker can provide against overloads, but reduce the amount of energy into a short circuit (and resulting damage) via fuses. Breakers will not cut off the energy into a fault until up to 1/2 cycle because they must extinguish the arc (in the breaker) at the waveform's zero crossing. Fuses can limit this because they will melt a lot faster.

Better idea: You look up plasma, and then post it here if you think it's so interesting.

Why is it that threads in these forums always have to turn into huge debates about something?

Good diagrams.

For the non-Sparky's, this is known as 'let-through current'. It can be very destructive. CBs and fuses are not directly interchangeable.

reply to whizkid3