Electric poles are essential in today’s world, as they support overhead lines. There are different types of poles used in different places. A steel tower is only used on transmission lines, for instance.
There are different poles for different applications. Before selecting a rod, it should have specific properties, such as a long lifespan, low cost, good mechanical strength, etc. There are also several factors to consider when selecting poles, such as the voltage, weather conditions, and the length of the line. This guide is all about electrical poles in detail.
Electrical poles are structures or columns that support overhead transmission lines, electric cables, telecommunication cables, transformers, streetlights, etc. Electric poles supporting transmission lines are called transmission poles. Telephone poles, street lights, power poles, telegraph poles, and other poles are available.
Types of electrical poles
The design structure of electrical poles, the material used for fabrication, application areas, etc., determine their classification. Several important factors to consider when designing electric poles, such as the pole’s mechanical strength and ability to carry the conductor’s weight in heavy winds. Furthermore, the design should be as lightweight as possible, maintenance hazards should be low, maintenance should be quiet, and handling costs should be low.
The Wooden electrical pole
Many years ago, wooden poles were used in low tension lines of 400 and 230 volts. A rod made of wood costs less than a pole made of metal. It is more expensive to construct a foundation for other bars, which is similar to the cost of building a wood pole. It can last for a long time.
Consequently, it was widely used because of all these features.
Wood from shawls was commonly used to manufacture electric poles since it was thought to be the best material. There is 815 kg of weight per cubic meter in shawl wood. The current situation and the effects of global warming have resulted in the discontinuation of wooden poles for the sake of saving the forests.
To accommodate the weight of the overhead conductor, wooden poles are classified into three sections. To make a pole, the wood used should be free of defects. In addition to straight timber, it is possible to use softwood as well. The curve can, however, be slightly curved despite being a bit more complicated. When feasible, you can combine two short lengths of wood to make this pole.
Lattice Steel pole
The use of steel towers for long-distance transmission of high power is shared. Transmission systems for overhead electrical power generally use steel towers. Steel towers are constructed by connecting metal rods, plates, angles, etc. Steel towers are not only expensive and time-consuming to install, but they are also difficult.
Steel towers have high mechanical and tensile strength, and they can carry more load, sagging, and span. The 66KV and 132KV transmission lines are all overhead transmission lines that have steel towers. In general, steel tower footings are grounded by driving rods into the ground.
Concrete electrical poles
It is important to note that there are two main types of Concrete Electric Poles.
- The RCC poles
- The PCC Poles
The RCC Poles
The full name of this material is reinforced cement concrete (RCC). Concrete cement is used to construct it, as its name suggests. It is reinforced with iron rods inside to enhance its durability. Earthling is performed by laying the earthling wire in a hollow channel in the pole or using copper strips 25 mm in size and 3 mm in thickness.
When laying gravel, we drill holes of 20 mm diameter on the pole to attach various fittings. It is more stable to use rods with a broader bottom than those with a narrower base. The PCC pole has a rectangular cross-section, not a square one.
The PCC Poles
Currently, PCC poles are widely used, and their full name is Plain cement concrete. Typically, this pole is used in systems with 11 kV and 400/230 volts. Additionally, this pole can handle voltages up to 33KV. This is also done for tension lines. Compared to wood poles, PCC poles are more robust than steel poles but not as strong as wood poles.
It is more expensive to buy such poles than to buy wood but cheaper than to purchase steel poles. Despite its long lifespan, this pole still has a lot of life left in it. In terms of maintenance, there is no cost. Compared to wood and steel poles, PCC poles are heavier and breakable.
Steel electrical Pole
Poles made of steel are mainly formed as rolled structures or tubular structures. Steel poles’ mechanical strength and light weight make them ideal for pole construction. Poles made of steel are generally used for 33KV and higher lines. City and urban areas, highways, and roads are the most common places that steel poles are used.
There is a high cost associated with installing and manufacturing steel poles. Compared to wooden poles, PCC poles, and RCC poles, steel poles can withstand more loads, span, and sag. Stepped and swaged tubular poles are also types of steel tubular poles.
Rail Electric Pole
In comparison to other electric poles, rail poles are the heaviest. There is a range of 9 m to 13 m between the top and bottom of the rail pole. Low tension lines (230V or 400V) are not connected to rail poles; mostly, 11KV and 33KV lines are connected to rail poles. Electrified rail poles are used in railroad overhead transmission systems.
Generally, electric rail poles are designed to be highly mechanically robust, highly tensioned, and capable of withstanding high vibrations. A high cost is associated with the manufacture and installation of the Rail Pole.
FAQs (Frequently Asked Questions)
What is a three-line electric pole?
Three conductor wires make up this cable. Electricity is carried by two of the three wires from the transformer, while grounding is provided by the third wire. A voltage between 120 and 240 volts is present on these lines.
Is there a specific term for large electric poles?
Overhead power lines are supported by tall structures, usually steel lattice towers. The British English term pylon may also be used to refer to a transmission tower, electricity pylon, or simply a pylon.
What is the purpose of having three wires on an electric pole?
There are generally three wires, known as conductors, in these devices. A conductor represents one phase of voltage. There are, therefore, three conductors in the RYB phase. We see towers transmitting 400 or 220 kV electricity in the fields, countryside, and highways.