110v out of 220v ?

[woodturner]

If you care to discuss this, PM me.

It seems pointless to discuss with someone who is not listening and does not want to learn, but I am starting to understand why you have the reputation here that you do (thanks for the PMs, folks).

[master53yoda]

As an electrical engineer, I disagree. For example, one application for aluminum wiring is in environments that are corrosive to copper. In those environments, copper wouldn't last a day.


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I'll only say that my statement was that he was correct that copper is a better conductor material was 99% accurate you proved my and his point by bringing up the 1%that would make copper not acceptable all though that environment would in all liklly hood require special consideration with-in the application of the code etc. there are always exceptions to the rules.

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 will

[master53yoda]

Thats it on this one I'm done and going out to the shop and drive some framing nails with a hammer.

[woodturner]

there are always exceptions to the rules.

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.

Classic issue between engineering and the trades. Engineering understands all the details and issues, but the trades have a better handle on the mechanics of doing the work. Often, the trades don't have the "whole picture", so they install things in a little different way they think is "better", which causes issues because they didn't have the "big picture". Example - the convention center floor collapse in pittsburgh.

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.

[LCHIEN]

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.

[yuri]

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.

[woodturner]

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

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.

[LCHIEN]

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.

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.

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.

[cabinetman]

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.
.

[Black wallnut]

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.