Boiler w/ millivolt gas valve turned on by itself (no thermostat call for heat).

EdTheHeaterMan

Dear @mattmia2,

You say that you already explained it. I can't seem the find the part about "abnormal amount of current isn't a necessary condition of a short" in any of the references I provided. Those references clearly state in more than one way that there IS a Spike or over current or low impedance associated with a SHORT.

If we were talking about a house current, that low impedance or spike or too much current would cause a circuit breaker to trip. On a thermostat that connects a 24 volt transformer to a gas valve or other load of normal impedance, if you short the R and the C it would probably let all the factory smoke out of the transformer. In this example above, the millivolt generator is not creating enough electricity to cause an overheating condition but a Dead Short would result in NO HEAT. The condition above is TOO MUCH HEAT as a result of a unintentional completed circuit and therefore is not a Short Circuit. No matter how many times you try to explain it.

Please show the MATH as you stated above that you would!

I'll help with the diagram. Two of these are short circuits. One is not

EdTheHeaterMan

I have cited four different authorities other than myself that contradict your opinion. Cambridge Dictionary, Wikipedia, electricschool.org, and an expert in HVAC wiring that the AHR Expo folks thinks enough about their electrical acumen to host their “mini seminar” for all trades people to learn from. I'm not saying that I am absolutely correct on this matter. I'm debating with references that I believe are credible.

I'm looking for some references from you that provide factual guidance that clearly states that an abnormal amount of current isn't a necessary condition of a short. I have looked all over and I can not find that statement anywhere other than here in your post that is stating your opinion. Please help me find the truth!

mattmia2

EdTheHeaterMan said:

Dear @mattmia2,

You say that you already explained it. I can't seem the find the part about "abnormal amount of current isn't a necessary condition of a short" in any of the references I provided. Those references clearly state in more than one way that there IS a Spike or over current or low impedance associated with a SHORT.

If we were talking about a house current, that low impedance or spike or too much current would cause a circuit breaker to trip. On a thermostat that connects a 24 volt transformer to a gas valve or other load of normal impedance, if you short the R and the C it would probably let all the factory smoke out of the transformer. In this example above, the millivolt generator is not creating enough electricity to cause an overheating condition but a Dead Short would result in NO HEAT. The condition above is TOO MUCH HEAT as a result of a unintentional completed circuit and therefore is not a Short Circuit. No matter how many times you try to explain it.

Please show the MATH as you stated above that you would!

I'll help with the diagram. Two of these are short circuits. One is not

In part 2 there should be no current. the current that is lighting the lamp is excessive. the nail provides a low impedance path past the switch regardless of the state of the circuit.

EdTheHeaterMan

mattmia2 said:

You say that you already explained it.

In part 2 there should be no current. the current that is lighting the lamp is excessive. the nail provides a low impedance path past the switch regardless of the state of the circuit.

I see your point. @mattmia2 But I don't see how the nail is any different than the switch. There is no increase current from the nail or the switch. By your definition the switch would also be considered a short circuit whenever it is closed. The same amount of electric current would flow thru the switch or the nail. One being intended the other being unintended.

The Horizontal nail that goes across the wires connected to the battery terminals does have a low impedance current because there is no load. Are you saying that the horizontal nail and the vertical nail in my diagram are moving the same current, the same amperage, The same amount of energy? If so, then why would the battery heat up so fast on the horizontal nail and not so much on the vertical nail diagram?

I am really trying to understand your terminology. I thought that impedance was the measurement of the complete circuit current. Not just the measurement of any particular piece of the circuit. The Nail is part of the circuit that includes the wires the battery and the load, in one case (the one that is not a short circuit).

The Nail is part of the complete circuit that includes only the wires and the battery in the example of a Dead Short. The impedance of the nail is only relevant to the circuit that it is a part of.

Am I wrong on this? Can you cite any authority on the subject to back up your opinion.

mattmia2

the "an abnormal amount of current" is to cover this condition where there is a low impedance connection between parts of the circuit that are already permanently connected.



The nail in this example is a low impedance connection between 2 points in the circuit but it does not cause an abnormal current.

The examples in the wikipedia article are not complete. That is probably why it is flagged.

The circuits textbook doesn't define short circuit, it just assumes you know it is 2 nodes connected together.

This is the definition of short circuit from the ARRL 6th edition General Class License Manual. It says that it is often across the supply but does not state it has to be:

EdTheHeaterMan

That is what I'm talking about. This is an example of an authority, other than you, that can confirm your point of view. Obviously the ARRL 6th edition General Class License Manual leaves room for your interpretation and hence the reason for this debate. There are some authorities that leave room for your interpretation while others don't. I guess that the source of one's education in electricity will make it impossible to ever have the “DEAD SHORT” and the “Shorter circuit that eliminates ANY portion of a circuit” will forever be debated. Source of my electrical education and your electrical education are at odds. My source specifically mentioned that the R and W unintended connection is NOT considered a short but may be mistaken for a short. Your source of electrical education allowed for the R and W unintended connection to be termed a short circuit. Perhaps we will just have to agree to disagree on this topic because of our different educators. Not because we disagree on the facts only on the definitions that were taught so many years ago.

Since I am not an authority on the subject, I am only the receiver of the information, and can only repeat what I was taught. The publisher of a training manual for the education of electricians in passing the licensing test does have more credibility than my understanding based on similar authorities of times past. It seems that those in the role of the teachers of the trade can not agree. How are we, the mere pawns of the trade, to have a consensus on this topic

I can understand your term of short circuit in this context to be true in this situation and accept that to be accurate the same way as two people that speak different languages may see that all words in one language may not have an exact translation in the other language. I will concede a partial victory to you and @109A_5 . Although the one source you provided is not going to change my understanding, I will concede that you are correct based on your training and therefore call for a draw on this debate. No winner, no looser. No one is absolutely wrong. No matter how right I am LOL


EDIT: I do have to admit, it was fun pushing @109A_5 buttons on this and watching the steam boil out his ears in his replies.

neilc

horse is dead now ?

ratio

EdTheHeaterMan

neilc said:

horse is dead now ?

Almost. I need to see how @109A_5 takes this news.