Aluminum Wiring Facts and Fallacies

When first used in branch circuit wiring, aluminum wire was not installed any differently than copper. Due to increased copper costs in the mid 1960’s, aluminum wiring became more prevalent in wiring homes. It was known at the time that aluminum wire requires larger wire gauge than copper to carry the same current.

For example, a standard 15-amp circuit breaker wired with No. 14 gauge copper requires No. 12 gauge aluminum. Typical connections from electrical wire to electrical devices, also called terminals, are usually made by wrapping the wire around the screw terminals and tightening the wire or pushing the wire through the back of the outlet. Over time, many of these terminations to aluminum wire began to fail due to improper connection techniques and dissimilar metals. These connection failures generated heat under electrical load and resulted in overheated connections.

History of Aluminum Wire

Electricity is transmitted from the utility generating stations to individual meters using almost exclusively aluminum wiring. In the U.S., utilities have used aluminum wire for over 100 years. It takes only one pound of aluminum to equal the current carrying capacity of two pounds of copper. The lightweight conductors enable the utility to run transmission lines with half the number of supporting structures. The utility system is designed for aluminum conductors, and utility installers are familiar with installation techniques for the types of aluminum conductors used in utility applications. Prior to 1972, the aluminum wire was manufactured to conform to 1350 series alloy. This alloy was specifically designed for power transmission purpose. Due to its mechanical properties the 1350 alloys were not suitable for use in branch circuitry. At this juncture in time a “new technology” of aluminum wire was developed, known as AA-8000 series which is the current aluminum wire used today for branch circuitry, however it is extremely rare to find in branch circuit wiring. This type of wire when installed properly can be just as safe as copper wire.

Problems with Aluminum Wires

Aluminum wires have been implicated in house fires in which people have been killed. Reports of fires with aluminum wiring generally show that poor workmanship led to failures. Poorly made connections were too often the cause. There were several possible reasons why these connections failed. The two core reasons were improper installation and the difference between the coefficient of expansion between aluminum wire and the termination used in the 1960’s.

Feeder and branch circuit wiring systems were designed primarily for copper conductors. Aluminum wiring was evaluated and listed by Underwriters Laboratories for interior wiring applications in 1946; however it was not used heavily until 1965. At that time copper shortages and high prices made the installation of aluminum branch circuit conductors a very attractive alternative. At the same time, steel screw became more common than brass screws on receptacles. As aluminum wire was installed more frequently, the industry discovered that changes were needed to improve the means of connecting and terminating smaller aluminum wire. Installation methods for utility grade aluminum, or series AA- 1350 alloy were also different and workmanship was an important factor in making reliable connections.

The most often identified culprits for poor workmanship involved: incorrectly tightened connections, wires wrapped the wrong way around the binding screws, and aluminum conductors used in push-back connections or with devices meant only for copper. Because the connections were made incorrectly, a chain of events of failures erupted. The connection was loose to begin with due to improper tightening torque, and the physical properties of aluminum / steel interface tended to loose the connection over time. Aluminum and steel have significantly different rates of expansion which would increase the resistance and temperature at the termination point. Similar problems occurred when aluminum conductors were incorrectly terminated in the push-in connections intended only for copper wire.

Corrosion is often cited as a contributing cause of aluminum connections. In 1980 the National Bureau of Standards performed a study to determine what caused the high resistance at aluminum / steel connections in receptacles. The study revealed that the formation of intermetallic compounds (alloys of aluminum and steel) caused the high resistance terminations, not corrosion or aluminum oxide. The thin, protective layer of oxide on aluminum conductors contributes to the excellent corrosion resistance of aluminum. When terminations are made correctly, the oxide layer is broken during the termination process allowing the necessary contact to be made between the conducting surfaces.

One of the most fundamental principles of electrical safety for wiring buildings is that high temperatures are hazardous. Heat is a major contributor to potential electrical hazards. A compromised connection creates additional heat. The additional heat contribution can “snowball” problems. Sometimes if sufficient heat is created, it can start a fire. Even if the heat does not directly start a fire, the heat can melt and or burn away insulation, which can create a short that may arc. Electrical arcs often reach temperatures in excess of 10,000 Fahrenheit. Aluminum wired connections in homes have been found to have a very high probability of overheating compared to copper wired connections.

Upgrading aluminum wired homes

There are several “upgrades” that are commonly done to homes with pre-1974 aluminum branch circuit wiring:

o Ensuring that all devices are rated for use with aluminum wire. Many are not, since they do not meet the CO/ALR specification

o “Pigtailing” which involves splicing a short length of copper to the original aluminum wire for use with devices not CO/ALR rated

o COPALUM a sophisticated crimping system that creates a cold weld between copper and aluminum wire, and is regarded to be a permanent, maintenance free repair. These connections are sometimes too large to be installed in existing enclosures. Surface enclosures or larger enclosures may be installed to remedy this problem.

o Completely rewiring the house with copper instead.

When deciding to repair or replace any electrical installation, a qualified professional should be consulted. The majority of homes wired with the general purpose circuits wired with aluminum are now over 30 years old. The likelihood of experiencing any problems unique to having aluminum is slight.

Any electrical system should be evaluated every 10 years by a qualified electrical professional to determine if it is likely to operate safely under the increased loads in different rooms being used differently, i.e. home office or bathrooms with larger dryers.

Scrap Aluminum Grades – How to Sort and Clean Scrap Aluminum to Maximize Its Value

Aluminum is a non-ferrous metal (which means it will not draw a magnet) that is lightweight. There are several different grades of scrap aluminum, and all of them vary in price. At most scrapyards, aluminum is broken down into the following grades:

Cast Aluminum

Radiators (clean and contaminated)

Extrusions (clean and contaminated)

Wheels (Clean and Chrome Plated)

Siding

Aluminum/Copper Radiators (clean and contaminated)

Old Sheet

Cast aluminum is very brittle and when broken, the inside will appear very grainy. A majority of the cast aluminum that comes across our scale is from auto parts. Transmission housings, engine cylinder heads, and electronic covers are all examples of cast aluminum auto parts. Other miscellaneous items that are made of cast aluminum include BBQ covers, some hot plates and skillets, and some light housings.

Aluminum radiators can be brought to our yard in two forms, contaminated or clean. A clean aluminum radiator must have all tanks, hoses, and steel and plastic removed. The plastic tanks on each end of the radiator will typically contain steel, sometimes however they will contain a tube made of aluminum or brass.

Extrusion is the process of pushing material through a die to give it a particular shape, very much like a Play-Doh spaghetti machine. The most common form of aluminum extrusion we see is window frames, but it is used very often in other framing systems and structural applications. Extrusions are broken down into contaminated and clean grades, with clean extrusion containing no steel, plastic, rubber, or insulation.

Aluminum Wheels come in two varieties, aluminum and chrome plated aluminum. Chrome plated wheels are worth a little less than pure aluminum due to the chrome contamination. Wheels with plastic face covers are also considered chrome plated due to the contamination of plastic and glue. Our listed wheel price assumes wheel weights, valve stems, and center caps are still attached. If these have been removed from your wheels discuss it with our scale operator and he may be able to increase your price.

Aluminum siding also includes gutters, downspouts, and other flat stock aluminum items. To receive the aluminum siding price, the material must not contain steel, Styrofoam, tar, insulation or any other contamination.

Aluminum/copper radiators are found in air conditioning units. They are copper tubes surrounded by aluminum fins. A clean aluminum/copper radiator will contain no steel flanges. If the steel flanges are cut off of a dirty aluminum/copper radiator, the rest of the radiator can be sold as clean and the flanges can be sold as aluminum breakage if they still contain some aluminum and copper.

Old sheet is the lowest grade of scrap aluminum and just about everything that has not been mentioned so far falls into this category. Some common aluminum sheet items include pots and pans, pop cans, lawn chairs, and screens. Siding containing excessive Styrofoam or tar will also be bought as aluminum sheet.

The Benefits Of Aluminum Windows And Doors

There are a variety of favorable benefits that aluminum windows and doors can supply a homeowner with. In fact, Aluminum is one of the most cost effective materials that a homeowner can invest in for their windows. If you’re on a budget then you can enhance traditional aluminum for reinforcement, but still save money.

So, for the most part a homeowner can have attractive windows and doors created from aluminum at a most exceptional value. Again, more composite materials can be added to improve the quality. Even if you use only a small portion of aluminum in the composite materials you’ll find some savings stemming from this. These are extremely reliable in many elements. Furthermore, aluminum can come in traditional features.

There is standard aluminum, which is used to construct windows and doors for those who live in the more mild regions. Then there is the thermal proof style of aluminum doors and windows. This latter style is for those who live in the regions of the United States, which face the harshest of elements, specifically the winter and summer months. Thermal proofing guarantees that high quality energy efficiency that homeowners are seeking today.

Creating A Customized Look For Homeowners Today

Many homeowners consider high-level aluminum windows and doors for sections of their homes such as a newly constructed patio. Aluminum patio doors come in a variety of styling choices that can match a home perfectly, as do the windows. If it hasn’t been mentioned aluminum windows and doors are customized and can have several finishes to satisfy a homeowner.

This is an individual preference and varies by tastes. However, aluminum windows and doors that are reinforced, or double insulated provide high security, along with that perfect energy efficiency. Many manufacturers often prefer aluminum windows themselves. They are some of the most easily customized.

They are also easily upgraded to strengthen and support a home’s exterior. One main feature that most homeowners aren’t aware of is the fact that many aluminum windows and doors come with lifetime guarantees. You won’t lose money by investing in these at all. Just a few of the reasons that aluminum windows themselves are beneficial is strictly due to the fact that these:
– Offer far more color options than any other vinyl window possibly can
– They can be customized to suit the homeowners preferred tastes
– They also have the ability to strengthen windows that are larger and in combination with others
– They can strengthen the external frame structures

Quality That Is Affordable And Provides Lasting Benefits

When it comes to aluminum doors, some of the same benefits are found. You might not think a door could be customized if aluminum, but it certainly can. Aluminum doors outlast even those traditional wooden doors. They also provide more dexterity and versatility than any patio vinyl door could hope for.

Aluminum doors and windows have a protective resistance against corrosion. It’s true that while many doors and windows will eventually corrode, and need replaced, aluminum can be far more dependable in some cases. Shockingly, aluminum windows can hold up under brute force longer than vinyl windows and wooden windows.

Even wooden windows sometimes depend on some form of aluminum reinforcement. While wood and vinyl windows used to have higher energy resilience, aluminum windows are just as reliable when they have a thermally insulated glazing system. This has become quite common today.

Aluminum is Economically Preferred by Most Manufacturers for Windows and Doors

Aluminum is simply a preferred composite material for many reasons. Aluminum can be recycled, and it offers durability that is hard to find. Aluminum holds up under extreme wear and tear too, providing perfect economic savings. Furthermore, it is the preferred material for school windows.

The reasoning behind this is simple. The windows are much larger for one thing. Secondly, aluminum simply can’t rust and it won’t create any condensation issues either. These features actually minimize maintenance that has to be carried out.
The same can be said for aluminum windows and doors in general. Both are time efficient when it comes to cleaning and maintaining them.

Furthermore, aluminum can be enhanced in any number of ways. They can be painted practically any color, or they can be used as enhancements for wood windows with regard to weather proofing and such.

The techniques for aluminum windows and doors are just really limitless from many respects. Both aluminum windows and doors are almost resistant to chipping, cracking, and even denting it would seem. Even if there is a hairline scratch, it can be easily corrected on this material. Vinyl is not so easy, and wooden windows definitely aren’t easy to correct.

This all certainly explains the rise in popularity, and with the means to enforce these; it is no wonder that more and more homeowners are turning to aluminum windows and doors as proper home investments.