Irish Counts спросил 2 года назад
Precautions For High Voltage Installation
High voltage electrical power lines are often installed on utility poles, however they can also buried. No matter where you work it is crucial to be aware of the correct procedures for working with high voltage electricity.
An electric shock is the most hazardous. This could cause serious injuries or even death.
Insulation
Insulation is a vital part of high voltage installation and it needs to be maintained at appropriate levels to not only guard against failure, but also to prevent electric shocks. Insulation acts as a barrier between electrodes and other circuit parts that make it impossible to contact them directly. This can cause injuries or even death.
Insulators can be made from different materials. Traditionally, rubber was the most popular material because it was easy to manufacture and performed well in the most extreme conditions. Plastics have replaced rubber as the preferred material for high-voltage applications.
Some plastics are more resilient than others. You must carefully consider the properties of each material before deciding which one is best suited for your project. Particularly, you must know the strength of each, how durable it is, its flexibility and how it handles abrasion, moisture and moisture.
The properties of thermal and chemical properties are also crucial. These properties will aid you in selecting the best material for your requirements.
It is essential to ensure that insulation is resistant to heat and pressure when used in high-voltage environments. Choose one that is able to stand up to temperatures up to 1000°C as well as humidity.
You should also look for insulators that are resistant to fire and other dangers. This could include a material that is resistant to sunlight and ozone. It is also waterproof and resistant to oil and chemical.
It is essential to look for insulators that can stand up to the high tensions that come with power transmission. These insulators can be suspended or strain insulators or shackle insulation.
These insulators are employed to prevent dead ends or sharp corners on power lines in which a heavy tension load is expected. Depending on the line’s voltage the insulators may consist of several glass or porcelain discs, which are joined in series by metal links.
Sharp Points
Conductors with sharp edges or High Voltage Installation sharp points increase the risk of dielectric breakdown in high voltage spikes. The majority of manufacturers have recognized this and made it a priority to make use of heat-shrink tubing that has adequate dielectric strength. A well-designed system will also employ measures to avoid the risks of trimmed insulation that isn’t properly cut which is a frequent cause of accidents for High Voltage Installation the experienced high voltage installer.
It is recommended to hire a qualified contractor to ensure a safe and successful installation. The best contractors are familiar with the risks associated with high voltages and have a solid safety plan. This is the most challenging part of the procedure. It is important that every member of the crew understands his or her job and is able to use the terms high-voltage.
Dust
In order to ensure the safety of personnel and prevent injuries, it is essential to ensure that dust does not enter a high voltage installation. Dust tight constructions are a good choice. It is also recommended that a protective cover be applied to the insulation.
Metal dust and insulating fibres are often mixed in high-voltage equipment. Because they share similar characteristics in terms of their movement and discharge characteristics A small amount of each can reduce the breakdown voltage of an open air gap.
It isn’t known how these impurities impact on the nature of the breakdown of an air gap. To better understand the discharge phenomena of these materials, a series of experiments were conducted to study their discharge behavior and motion both separately and together.
As illustrated in Figure 10, the voltage of lifting of dust particles varies as the particle’s size decreases, but the motion law remains unchanged. The particles are transported primarily to the upper electrode when the voltage is less than 7 kV, and then they bounce violently between electrodes when it reaches -14 kV.
In order to observe the discharge and movement of these two materials in depth the tests were conducted using cameras that operate at high speeds. The results showed that metal dust and insulating fibres could be divided into three states: close and contact sate (or distant sate) distant sate (or jump sate).
The dust of metal that was in contact with sate moving towards the electrodes. The area of movement created an area of dust columnar between them. This area had a relatively low dust concentration.
The insulating fibers however did not move when voltage was low, but started to rise when voltage increased. The voltage jumps between electrodes were quite interesting.
During the test, the voltage was increased from -7 kV up to -16 KV. Then the metal dust and insulating fibres started to move quickly. As the insulating fibres lifted their weight, they bounced around the electrodes, causing an abrupt change in their movement. A huge amount of dust particles also ejected from this area and caused an explosion.
Voltage Breakdown
Breakdown occurs when an insulator undergoes rapid changes in its electrical installation service properties. This is caused by an electric field strength locally that exceeds the dielectric strength of the material. This can occur in air or any other insulator and can cause shock, burns, fire or even an explosion.
Depending on the material and shape of the object different voltages can cause breakdown. Therefore, it is important to test the materials that are used for high voltage installations.
For example, the drain-to-source current determines the breakdown voltage for a semiconductor device like a MOSFET. A technique known as gate-current extraction can determine the value.
Another method of measuring the breakdown voltage is to put the sample between two electrodes and applying a high voltage to it. The voltage is then increased until the material is broken down.
The breakdown voltage of an insulation depends on the material used and the distance between the electrodes, as well as the electric field strength at the contact. This is an important factor in determining how much voltage can be safely applied to an insulation.
Engineers can use dielectric breakdown tests to determine the maximum voltage their designs are able to handle. It can also be used to track changes in the insulator’s ability to resist voltage.
Copper and aluminum are more prone to breaking down than other. For example, aluminum can suffer a voltage of up to 3 kV/mm exposed to dry air at normal atmospheric pressure. This is the reason why aluminum cable is rated at lower voltage than copper.
Other insulators, including silicon, can experience breakdown voltages that can reach 3.5 KV/mm when exposed dry atmospheric air at normal pressure. This is due to the fact that silicon conducts at lower temperatures than aluminum.
Impurities, such as bubbles, can cause liquids’ breakdown. This can result in a non-linear electric field strength between the electrodes which can increase the potential for breakdown.
It is a good idea to protect the surfaces of conductive devices using dielectric materials such as glass or plastic. This can help safeguard against the possibility of breaking and the hazards that go along with it.
