Pay me now or pay me later. Cheap material, more maintenance and care. Better material, less maintenance and care. Cheap material mainly good for a constant never changing load (utopia). Better material in the real world where loads will go where they need to go.

S&C High Voltage switchgear has used aluminum for years. They use a pentrox joint compound that has aluminum in it for all joints. I have never found a problem that was not caused by some outside source.

I have surveyed may low voltage aluminum bus systems 800-3000 amps. I have found enough problems that some of my customers have these bus infrared tested twice a year.

The other big factor like realestate is Location, Location, Location.

During my early years in the 70's I worked at a GE switchgear plant that "welded" copper ends to Alum buss bars. this was done under high pressure and welding current. Not sure if this is still done anywhere and how this process worked out in the field. They did destruction testing of the mechanical strength of the joint in the factory. The copper ends were silver plated. These short pieces of copper/alum were then welded to the alum buss bars

aluminum, wire ,bars and other devices of this metal have shown a weekness in residential, commercial,and industrial applications in my ,forty years in the industry, compared to the more expensive alternatives. you get what you pay for.

Reference earlier comment - please correct website address to www.eaton.com/consultant - sorry typing error.

Refer to Eaton Consultant website: www.eaton.com/consutant , select in the Related Information pull-down menu, Technical Papers and under Electrical Distribution, the paper " Aluminum the Other Conductor by Bob Yanniello - Division Engineering Manger for Electrical Assemblies Division.

Hello,

Aluminum wiring, eh? In a high rise???

I recall watching a famous movie, (ten+ years ago), where a newly opened enormous high rise building was burning up from the inside out. (Does anyone remember the name of that movie?)

Ultimately, the cause of the fire was do to the illegal installation of sub-standard electrical materials, i.e. aluminum, that was unscrupulously used, (not design specified), for the original building electrical installation. A higher profit motive was admitted by the amoral design/installation contractor.

Funny how fiction can be a harbinger of the future. And now we see the seeds of this fiction possibly playing out in real life.

Unfortunately, today none of the real life players have what the fictional players had. It's what I call, "The Luxury of Ignorance". Instead, they all, from the bottom up, know EXACTLY what can happen when using aluminum.

Stay tuned! Film at eleven!

I wanted to address the issue of Medical Facilities which never (seem) to shut down. I worked at a hospital for over eight years in California. The hospital was required to have every electrical distribution panel, ATS, VFD, and motor control units Scanned yearly to identify any loose connections and or potential over heating of conductors, contactors or any electrical component found in these enclosures. A detailed report was presented to the facilities manager and potential problems had to be addressed and corrected within a time limit. These tests were required in order to qualify for accreditation and affiliation for certain program funding and was just one component of a whole host of inspections that take place.

It is interesting to see the actual connection data on aluminum and lugs in the low voltage and sizes under 4/0. A paper published by ALCAN showed that the connection method is NO anti-oxidation compound, one terminal at max torque, a second test terminal at minimum torque. The lug and wire are subjected to max current; then dipped in 4 degree centigrade water, then up and to full current (I think I have the protocol correct).

The point to me was that the larger sizes of AL wire performed well in less that the conditions we normally provide.

A hospital setting and high amperage make the material less of a factor in the overall cost of the installation.

Lynn Adams

Interesting to note last April I sat in on a sales presentation promoting the opposite not aluminum based but steel copper buss work being a conductor better than aluminum with out the vibration inherent with aluminum connections. unfortunately I didn't get the vendor number and have heard nothing of this type of buss work . Has anybody else heard or used this compositional material?

I agree with your concerns, however, as others have posted the Aluminum material is not the problem. The real problem is with the connection points. As you pointed out, two areas where I have seen Aluminum to be most problematic are the breaker-to-bus, and breaker (or did you mean bus) to cable. The termination points. If not properly installed by qualified persons, you will have trouble. Along with this goes maintenance. I would think your institution should have an agressive maintenance program, especially when Life Safety is concerned.

Quality workmanship and proper maintenance should ensure a long reliable life for the facility....and satify the bean counters.

Tin plated aluminum box lugs ( the usual kind in a lot of 120 volt to 600 volt stuff ) is a proven product and in a lot of environments lives a lot longer than unplated copper lugs.

SquareD's tin plated aluminum products ( using the Alstan 80 process ) are also proven. I would stay away from silver plating because silver develops a nonconductive black tarnish. Silver also has some other problems such as turning into a conductive metal wool when exposed to hydrogen sulfide. There is also some belief that silver can solid to solid diffuse into wire insulation.

I know someone who has a 23 year old house about 1/2 a mile east of Interstate 271 in Pepper Pike, Ohio. The catalytic converters are already eating the copper wiring that is inside of his house. There is a reason why there are antioxidant compounds that are for use with copper wire.

Every instance of where I have hooked up a plastics machine or air compressor with aluminum shows that all you have to do is to fan out the wire strands, cut off the sharp tips, clean each strand with #220 silicon carbide abrasive paper, and then grease each strand with antioxidant compound. There are also issues such as overstripping the conductor so that you can have a strand bending area and using a screwdriver shaft to establish a bending radius and using a hose clamp to recompress the wire strand and then chamfering the outside strand with a file so that they will slipp into the lugs but that is the general idea. Compact stranded wire strand have some concave surfaces that are difficult to clean but I have found that if I hold 1 end of a silicon carbide paper strip with my little, ring, middle fingers and use my thumb and index fingers to press the other end around the wire strand I get excellent results.

The one problem that I have not licked is cleaning antioxidant off of my tools and hands in the field without having toi expose my hands to brake cleaning spray.

Oh yeah, Sefcor makes lugs that you weld to aluminum conductor with a tungsten inert gas welder. This simplifies the silicon carbide paper-elbow grease-electrical grease problem to 2 flat surface each lug. I asked Alcan about this and they said that I should bridge the wires strand using 4043 filler rod.

You can also get lugs that you exothermically weld to copper wire. You would still need to use silicon carbide paper to clean off copper oxide after the lug cools.

I remember Aluminum...however now there may be different compounds available now than what was generally used years ago. I would be asking "What has changed between then and now?" Someone has had to do research on component joint connections, which is probably dry reading, but very important reading never the less. Copper is becoming expensive, which is most likely the reason for the drive back to aluminum. The question is important: "What has changed between then and now?"

I have been in the electrical design/build business for over 35 years. I have been involved with every type of project from power plants to chemical plants and all types of commercial buildings. In the 60's and 70's copper was just as more costly as aluminum then as it is now. If I value-engineered a project as the electrical contractor, substituting aluminum for copper was usually railed by the design engineer. The material itself (if used in a proper application) wasn't the problem, it was always the connections. Bus bar connections weren't an issue usually, but cable terminations were. Many contractors did not properly terminate aluminum cables, and problems were sure to result from corrosion and flow of the Al material from a bolted type of termination. If maintenance was performed routinely to torque the lugs, that would alleviate the problem, but how often did that happen? With the advent and wider useage of hy-press type compression connections, the Al termination problem was pretty well eliminated. My analogy I give to owners/engineers who think Al is not safe is to illustrate what the utilities use to generate and transmit power from their facility. Virtually without exception, the utilities use aluminum cable, wire, bus bars, generator windings etc. in all of their generating, transmision lines, and tranformers. The only copper one might see in their systems is in smaller power cables and control cables. So the utility, which is very concerned about not only cost but maintainablitiy might use Al in not only generating your power but transmitting it perhaps hundreds of miles to a customer, and the customer might be worried about using Al for the last 100 or 200 ft. or in his switchgear. Of course the electrical system needs to be installed properly by a qualified contractor, and some maintenance needs to be performed on it like any other critcal building system.

We operate many large industrial and commercial buildings. We have had bad experiences with aluminum wire, but the problem has always been caused by improper terminations. We now use copper for all wire and cable, but allow aluminum bus in panelboards and switchboards where the design and connections are controlled by the company that manufactures them. This equipment has proven to be reliable, but all equipment must have proper periodic maintenance to give trouble-free service.

Growing cost concerns have pushed the industry to reevaluate aluminum conductors as a viable option. Our office has successfully implemented aluminum conductors on a variety of projects from Healthcare to Recreation facilities. We have found that the compact stranded aluminum conductors that are available today are far superior to their past predecessors. We do, however, limit aluminum to sizes above #4. All conductors below #4 remain copper. This is largely due to the number of terminations that are made at the smaller sizes, but also considers the negligible cost difference of the smaller sized conductors. I'd also like to point out that I've seen many many failures in "copper only" systems in the past where a preventative maintenance program was neglected. Bottom line is that both need to be monitored and maintained, cleaned, scanned, etc. Good Luck.

Since the early 90's since AA8000 series aluminum came into the market, the larger aluminum conductors have become far superior over old conductors and busbars.

My biggest concern with using aluminum in the standard size wires, 14, 12 and 10, is that "Homer the Handyman" will not do things correctly. We experience this regularly in the sale of existing homes. If the homeowner does not know how to correctly replace and repair this wiring we will begin to have the same problems as the old wiring.

The homeowner generally goes for the cheapest repair not the best. With areas of the country where there is no licensing and where the modular homes are installed I believe all the old aluminum problems will resurface.

i think aluminum is fine.its more delacate but ive used it and seen it in old houses with out any problems.when you use the proper devices and connectors and no-lox.ive seen it wired right to copper wire with just a scotch guard wire nut.i was expecting to see something bad took off all the tape they rapped it in didn't see any problems.it wasn't to code it was just laying in the attic etc.

You are right to be concerned! There have been too many studies done, and too many instances where aluminium has failed to meet the needs of a rigorous environment.

Nothing has changed, except that the environment has gotten worse and aluminum will fail faster now, than ever before.

The people that are promoting aluminum, are doing so only to make their blood money, and then disappear.

The Eaton flyer on aluminum has been around for a while as have other Industry enticements. I replied to a thread on one of last years posts concerning acceptance of using aluminum wiring. Equipment aluminum bussing is a separate consideration as long as there are no flexing or acoustic constraints that degrade the interfacing connection integrity.

Texas Instruments developed Cu clad Al wiring for space flight vehicles and failed to get market acceptance. The main reason, Aluminum DOES NOT HAVE THE SAME MALEABILITY as copper. Heat and workhardened conditions are more of a concern in using smaller AWG conductors. The temperature cycling and creep due to cross-section expandability fails miserably in small conductor applications.

The aircraft industry tried aluminum for the same reason and rejected the many flaws Al has under vibration stress. As I mentioned before, I would not take a trip on an Al wired jetliner. The Government requires Spec 44 and 88 wiring using alloyed high strength copper and pays a pretty penny for having safe aircraft.

Until the metals industry can produce a copper flexible comparable alloy aluminum with compatible connecting terminations for reliable small AWG conductors in the commercial industry, is the day it will be accepted.

I am not an Engineer, but I would err on the side of caution. Having worked in some large industrial applications, I would suggest staying with the copper for this large power distribution and the application (Medical). My reasoning is the duty and the possibility of excessive expansion and contraction, as well as the Electronic Harmonic problem which could be created, I would also consult with the manufacturer of the switchboard and consider their recomndations. They would be the first to know if there have been any problems for this type of installation.

I have worked at a power company for over 30 years in maintenance of electrical power equipment rated from a few amps to over 30000 amps. Voltages from a few volts to over 500000. We use both aluminum and copper. Both require maintenance including scheduled shutdowns. It is not Ron Popiel you dont set it and forget it. Most of the problems I have seen are caused by the lack of maintenance or improper maintenance or installation. Over tightening of connections from both maintenance and manufacturers is a problem for both aluminum and copper. Both cold flow and cause loose joints. Unplated steel bolts corrode when used with aluminum or copper. Both oxidize and a joint compound is needed. Thermography, visual inspections, resistance checks, cleaning, checking connection tightness are all good tools to check for hot joints. Do not rely solely on methods that do not require shutdowns. If installed properly shutdowns can be once every 10 to 15 years. And that "IF" is a big one. As our failure analysis expert says "the correct answer is always depends". In this case both depend on good installation and maintenance practices and recognizing the appropriate design requirements and constraints.

There's nothing wrong with aluminum as a conductor or bus material as long as it's installed right. I work at a hospital and we have 1,000 amp rated AL bus duct that has been in service since 1970. The mfg has stated that it's beyond it's serviceable life and we have a plan to replace it within 3 yrs, but it'll have to remain in service until then.