aluminum vs. copper

[wyliesdiesels]

http://www.southwire.com/commercial/ALBuildingWire30YrsOfReliability.htm

http://www.southwire.com/commercial/todaysAluminum.htm

The newer AL alloy wire has been around for almost 50yrs with a proven track record. Nuff said

 

[Norcal]

Using the AL conductors from the 1960's as justification for the erroneous opinion that AL is unsafe is a bunch of BS, installed correctly aluminum alloy conductors are safe and reliable, but copper installed incorrectly is just as much a hazard as poorly installed AL alloy conductors.

 

[Speedy Petey]

That issue was with old style aluminum wire back in the 60's and 70's. New aluminum alloy used today in larger feeder/service wire does not have that problem and is safe and does not require re-torquing if installed correctly in the first place. Inferring that the old history of aluminum wire as being applicable with today's newer aluminum wire is incorrect.

This!

Unfortunately, we will always get folks stuck in the past that will not acknowledge that things change. We will keep hearing the 40 year old arguments.

 

[pattenp]

I think we got the point across.

 

[wyliesdiesels]

I like these better. wned: wned2:

 

[13.2kv]

The biggest problem from aluminum of the past was expansion and contraction loosening the connections over time and causing arcing in branch circuits, The POCO has been stringing up aluminum for years, yes some of the older stuff has given us problems over the years but as has been stated above, the alloys that are out there now negate all of the major problems from the past outside of continuous wet/damp location corrosion of bare conductors.

As was stated earlier SER is not allowed underground and at least one member basically said " The NEC says no so don't do it" However I always like to know "why?"

The "why" of the subject is that Aluminum is extremely reactive to minerals, especially salts, as stated above it literally does turn to mush in damp environments, you end up with a white mush or powder if it has dried and because SER had a bare neutral is the reason for the rule, and which is why we strictly use copper in coastal applications at the POCO.

 

[rburke65]

2" PVC conduit, sweep 90*s....NOT a regular 90* fitting! "Sweep 90". PVC is inexpensive. Do your self a favor and bury an extra conduit. It doesn't have to be another 2" but you could run an extra 1" or 1 1/2" ....or go crazy......do both! It's a good idea.

 

[Speedy Petey]

2" PVC conduit, sweep 90*s....NOT a regular 90* fitting! "Sweep 90". PVC is inexpensive. Do your self a favor and bury an extra conduit. It doesn't have to be another 2" but you could run an extra 1" or 1 1/2" ....or go crazy......do both! It's a good idea.

As long as you are buying your fittings in the right place you will only find electrical sweeps.

I get the impression when you say "regular" 90 deg fittings you mean plumbing fittings. A "regular" electrical 90 IS a sweep.

 

[gregtwojeeps]

As long as you are buying your fittings in the right place you will only find electrical sweeps.

I get the impression when you say "regular" 90 deg fittings you mean plumbing fittings. A "regular" electrical 90 IS a sweep.

Not where I shop at the local electrical supply house for 30 years now. ...RBurke is correct.

A" sweep" 90 for electrical PVC conduit is a long radius elbow, primary used in lateral services. It has a much longer radius that the standard electrical PVC conduit 90 deg. elbow.

 

[that-guy]

I've already worked a long 90* sweep into my plan. from this point I am just waiting on the right time to buy all of my materials and get to work

 

[myredracer]

If going with 2", use thinwall DBII PVC "duct". Much cheaper than sched. 40 PVC. With DBII, they make large radius 36" sweep bends. Use a rigid PVC to DBII adapter at each end. Can't have DBII above ground and with a 36" sweep bend may need to encase in concrete if poking up above grade at risers - check NEC.

 

[Speedy Petey]

Not where I shop at the local electrical supply house for 30 years now. ...RBurke is correct.

A" sweep" 90 for electrical PVC conduit is a long radius elbow, primary used in lateral services. It has a much longer radius that the standard electrical PVC conduit 90 deg. elbow.

Then it's a semantics thing.
Around here there are 90's and large radius 90's. BOTH are sweeps.

 

[WarDamnEagle]

How much in $'s is the difference between Al and Cu for an 80' run? We know Cu is equivalent or better so just curious.

 

[pattenp]

How much in $'s is the difference between Al and Cu for an 80' run? We know Cu is equivalent or better so just curious.

A lot. Can't you look up the prices of wire on the web?

 

[mg283680]

I worked as an electrician for a while. All the feeds from the street were aluminum.
Why not do what the local electrical code says to do?

 

[wyliesdiesels]

How much in $'s is the difference between Al and Cu for an 80' run? We know Cu is equivalent or better so just curious.

Kinda hard to answer that without knowing what size feeder you want...

 

[pattenp]

As an example, #2 aluminum for 90A for single conductor is about $0.32 per foot. #4 copper for 85A for single conductor is about 0.83 per foot. Copper is over 2.5 times more expensive for this amp size wire. So you could be talking $100 for Al vs. $250 for Cu for a four conductor 80' feed.

Here's a good site to get an idea on wire prices. http://www.wireandcabletogo.com/

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