Input Power Requirments for the 250EX

[Doug B]

By the way, 2 breakers tied together with a tie bar you put on. Is not the same as a 2-pole breaker you purchase with or without the tie bar.

Putting a tie bar on 2 single breakers are fine for split plugs or 2 circuits going to say the 2nd floor of a house, sharing the same neutral.

But when feeding a 220/240 volt device, the breaker should not only be mechanically tied together but also be thermal magnetic (Internally) connected to each breaker.


Now lets get back to some welding

Hemi:
I have never heard of a ganged 240 (240v) breaker having an internal electrical connection between the two halves. I think that would defeat the purpose of having independent internals. Can you refer me to anything that says a 240 breaker is anything other than two breakers tied together on the trip levers?

[HEMI]

Hemi:
I have never heard of a ganged 240 (240v) breaker having an internal electrical connection between the two halves. I think that would defeat the purpose of having independent internals. Can you refer me to anything that says a 240 breaker is anything other than two breakers tied together on the trip levers?

You know, you could just google it. But I googled it for you and just clicked on the first thing I found.
Another example would be a Square "D" 2 pole breaker. It only has one handle to throw the breaker on and off. It is internally connected. You could use 2 singles with a tie bar. But I have seen where the tie bar did not fit tight enough do to poor design or bad installation. With a loose fit, one breaker could trip leaving the other one energized.

Here is my search criteria I used to answer your request..

thermal magnetic 2 pole breaker

how a 2-pole internal trip works

Here is the very first result......

http://en.wikipedia.org/wiki/Circuit_breaker

Here is a good one from the Inspectors News Page

http://www.inspectionnews.net/home_i...-120-volt.html

[HEMI]

Breakers don't necessarily trip right at their designated amp rating. Each breaker's time/current trip curve determines how quickly it reacts to current above its designated rating. For instance, a 40 amp breaker should never trip if the current running through it is 40 amps or less. A little more current, say 45 amps, might cause it to trip after an hour or so while a lot more current, say 100 amps might cause it to trip in 10-15 seconds. A gross overload, such as a short circuit, would activate the breaker's secondary trip mechanism and would cause it to trip instantly. Different manufacturers have breakers with different trip curves. Most breakers these days -- have more forgiving trip curves, similar to slo-blow or time-delay fuses.

A good example of the differences would be to use a veritable load on say a Square D then an FPE breaker of the same rating. I know for a fact, the Square D will trip first. We used to joke about the FPE. You could almost weld with the breaker alone before it would trip. Where as the Square D trips quick.

[sschefer]

Breakers and Fuses are thermally actuated devices. They to don't care how much current is present. The temperature that they react to is an estimate of the amount of heat that should be present at a specific load. The materials in the breaker or fuse are such that they bend, twist, melt when they reach a specific temperature. Once a fuse melts it is rendered useless. In a simple breaker the substance inside is designed such that it will bend or twist at a rate and amount that will eventually cause the circuit to break, (open), and current will cease to flow. The materials are developed so that they return to a phsical form that is nearly the same as before the overheat so the problem can be corrected and the breaker can be reset. Over time, the heat from an operational circuit or from many overloads, causes the substance inside to become heat tempered and will not fully return to it's original physical form. Engineers have designed the breaker so that this tempering makes the breaker react earlier until finally the breaker cannot be reset.

Don't worry that you don't understand the many forms of electricity, just hire someone that does.

[HEMI]

LOL
Wow, I guess maybe I should not renew my license next time it comes due for renewal.
Thanks man, you saved me $68.00......

PS. When you copy and paste, you should give the original reference with it.


LOL

[performance]

Its about time to close this thread. Obviously some people know more about things than others, and not necessarily the ones that think they know so. But I don't mean to demean anyone or call anyone names. But sound advice has been given, but sound advice has been ignored...So, its a stalemate and the thread is not going anywhere positive.

Case closed. I think that we should know what our units require. That's all.