Risks with the Use of Aluminum Wiring
There are many factors that determine the risk level of a facility with aluminum wiring. Its always a good idea to have a trained inspector to conduct a full inspection of the facilitys electrical system. Exposure to electrical failure will increase during attempts in repairing these facilities.
Such hazards should be reduced as much as possible. It all starts with familiarizing the properties of the aluminum conductors and also the manufacturing changes. While outdated compounds have their risks, the new ones come with their own threats to safety.
Aluminum alloys are separated into a number of categories. The 1000 series is the basic one. When copper is used as the major alloying element, it belongs in the 2000 series. When manganese is used, it is categorized in the 3000 series. There are other series designations where zinc, magnesium, silicon and a mix of magnesium and silicon are employed.
One of the most common issues in the use of aluminum wiring is oxidation. When an oxide layer rapidly forms on the conductor, a high electrical resistance also surfaces. A barrier on the surface of the conductor forms during this phenomenon and with the blockage of any additional oxygen, further oxidation is prevented. However, it is the electrical resistance of the oxide layer that presents trouble when employed in electrical distribution. It is very high and even higher in heated environments. Thus, the aluminum oxide becomes an electrical insulator.
When fretting corrosion occurs, the trouble with oxidation becomes even worse. Problems such as erosion and corrosion affect the interaction of the aluminum with other metals in forming the compound. This yields to high electrical resistance.
After an extended period of time, a common failure with the aluminum wiring also occurs. When there is a splice or termination made with the conductors, the oxidation layer is disturbed and enough current flow is permitted. With the reformation of the layer, the electrical resistance of the connection tends to increase.
Such a behavior depends on the increase in temperature resulting to thermal expansion. It loosens the connection and allows fretting corrosion to occur. The protective insulation on the conductors becomes damaged with the rise in temperature. This affects the contact with other conductors and generates a fault to the grounded enclosure.
There are still a number of industrial facilities that use large aluminum conductors in the electrical distribution. Even with all the hazards involved, how these materials are applied determines how likely failure occurs. That is why it is of utmost importance to conduct an informed inspection of the facility.