Originally posted by cabinetman
110v out of 220v ?
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I have spent most of my life dealing with problems that were exceptions. 90% of the items i wrote up were installation problems , i pointed them out and the field people fixed them without any problem, on the other hand the 10% of the issues that i wrote up that were engineering problems most times required all but an act of the powers above to get resolved because I would have to back them into a corner in order to remove all the little side tracks and trivia so they had no other choice but to admit they were wrong.
Now if this didn't offend someone nothing willArt
If you don't want to know, Don't ask
If I could come back as anyone one in history, It would be the man I could have been and wasn't....Comment
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Thats it on this one I'm done and going out to the shop and drive some framing nails with a hammer.Art
If you don't want to know, Don't ask
If I could come back as anyone one in history, It would be the man I could have been and wasn't....Comment
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That was essentially my point - the blanket statement "copper is (always) better" was not accurate, there are usually exceptions or some situations that don't fit the majority.
on the other hand the 10% of the issues that i wrote up that were engineering problems most times required all but an act of the powers above to get resolved because I would have to back them into a corner in order to remove all the little side tracks and trivia so they had no other choice but to admit they were wrong.
I have certainly encountered engineers who refused to admit it when they were wrong, but I think they are few - the engineering process strongly encourages the correct result, regardless of whose idea it was or if someone has to admit they were wrong. From my experience, the attitude of many tradespeople that "engineers are idiots" causes many problems. It works best when engineering and the trades work together to combine their strengths and achieve the best result.--------------------------------------------------
Electrical Engineer by day, Woodworker by nightComment
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whenever someone says something is better or the best, I always wonder what the criteria is. That's almost always the reason that people don't agree on that kind of evaluation.
For example, Copper is better than Aluminum
or aluminum is better than copper?
Comparing Resistivity or conductivity - Copper
Comparing cost per resistance or resistivity - Aluminum
Comparing weight per resistance - Aluminum
Comparing resistivity vs size - Copper
Comparing thermal conductivity per foot of a given resistance - I'm not even sure...
Comparing corrossion resistance to a given environment - depends on the contaminents
So given their criteria, I'm sure everyone was right.Loring in Katy, TX USA
If your only tool is a hammer, you tend to treat all problems as if they were nails.
BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questionsComment
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Guys,
was little bit off this forum.
I would like to thank you all for advises and info you gave me. Now I have a clear picture of what I can expect out of my 220v outlet and how to proceed further. And of course I will play it safe, either following wiring code or hiring licensed electrician.Comment
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whenever someone says something is better or the best, I always wonder what the criteria is. That's almost always the reason that people don't agree on that kind of evaluation.
For example, Copper is better than Aluminum
or aluminum is better than copper?
Comparing Resistivity or conductivity - Copper
That's often one of the differences in perspective between engineering and the trades - electricians often "know" that copper has lower resistance than aluminum, engineers (hopefully) understand that while that is common, it is not always correct.--------------------------------------------------
Electrical Engineer by day, Woodworker by nightComment
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Another aspect is that the problem is incompletely specified. For example, does aluminum or copper have lower resistivity or greater conductivity? Most people would say "copper", but that is an incomplete answer. For a complete answer, conductor size and temperature have to be specified. There are conditions where aluminum has lower resistance that copper, so the statement "copper has lower resistance" is often true, but not always.
That's often one of the differences in perspective between engineering and the trades - electricians often "know" that copper has lower resistance than aluminum, engineers (hopefully) understand that while that is common, it is not always correct.
Resistivity and resistance are two different properties, but related.
Resistivity is resistance per unit length times the cross section area and is an inherent property of the material. Copper inherently is lower resistivity than aluminum; its a better conductor when comparing resistivity (or its inverse, conductivity). Resistivity is measured in ohm-meters.
Resistance is the property of a specific shaped piece of the material - a specifc length and cross section. When the shape is the same (same length, same cross section) copper resistance is lower, but if comparing two pieces same length but of different cross section (i.e. wire gauge), aluminum can be lower resistance if the diameter is larger (i.e. smaller AWG gauge number). Resistance is measured in ohms. The inverse of resistance, is of course, conductance, measured in Siemens.
the resistance of a piece of wire can be determined from the resistivity of the conductor, rho.
The resistance, R = Rho x L/A where L is the length and A is the cross section area of the wire.Last edited by LCHIEN; 09-23-2009, 08:08 AM.Loring in Katy, TX USA
If your only tool is a hammer, you tend to treat all problems as if they were nails.
BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questionsComment
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An always true statement is "copper has lower resistivity than aluminum."
Resistivity and resistance are two different properties, but related.
Resistivity is resistance per unit length times the cross section area and is an inherent property of the material. Copper inherently is lower resistivity than aluminum; its a better conductor when comparing resistivity (or its inverse, conductivity). Resistivity is measured in ohm-meters.
Resistance is the property of a specific shaped piece of the material - a specifc length and cross section. When the shape is the same (same length, same cross section) copper resistance is lower, but if comparing two pieces same length but of different cross section (i.e. wire gauge), aluminum can be lower resistance if the diameter is larger (i.e. smaller AWG gauge number). Resistance is measured in ohms. The inverse of resistance, is of course, conductance, measured in Siemens.
Ya beat me to it Loring.
.Comment
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Pure sadness
Folks this topic is now closed. For those of you that have posts contined in it that have disappeared it is because of off topic and endless nitpicking between members. Personal attacks, insults, and questions of each others charcter will simply not be tolerated. We the forum staff are still in duscussion on appropriate level of moderation for those involved. To all the members that viewed this from afar I am truely sorry it was not shut down sooner. We as a community are better than this. We expect our members to act with more grace and acceptance of each other.Donate to my Tour de Cure
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