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If you are looking for more details, kindly visit insulator porcelain.

It's largely in the ceramic shell of the insulator. There isn't any metal to metal contact, the ceramic is just for that purpose. Surprisingly, the ceramic of the insulator is strong in tension, but poor in shear, which is why they use short porcelain shells and make strings of insulators where one gets the benefits of high resistance, tensile strength, and shear resistance.
(source: aliimg.com)

(source: aliimg.com)

Siemens does indeed gave FRP rods, but they don't have the 12 ton rating that most ceramic string insulators have. The FRP are more suited to distribution than transmission where the tower to tower runs are less than 500' and the conductors no more than say Drake ACSR.

The post insulator in the bottom picture of the answer above is typical of a stand-off used in a substation, it tolerates compression loading only as it's not meant to withstand any shear or suspension loading. It's rare to see a stand-off on a tower, but they occasionally show up on distribution poles as long as they're accompanied by the appropriate shear/suspension appurtenances.

Ceramic Insulators

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Introduction

This article contains information regarding ceramic insulators and their use.

You will learn:

• What is a Ceramic Insulator?
• How Ceramic Insulators are Used
• Types of Ceramic Insulators
• How Ceramic Insulators are Made
• And much more …

Chapter One: What is a Ceramic Insulator?

A ceramic insulator is a non-conductive insulator made from red, brown, or white porous clay that provides a bridge between electronic components and has high dielectric strength and constant and low electrical loss. They are easy to maintain and resistant to stains and various residue forms. For many years, ceramics have been used as electric insulators due to their exceptionally high resistance to electrical current.

The wide use of ceramic insulators began in the 1950s. They were cheaper to make and more resilient and long-lasting regardless of the climatic conditions. The manufacture of glass insulators stopped in the 1960s and was replaced entirely by ceramic insulators by the 1970s. There are still a few glass insulators in use, but only a tiny percentage.

Chapter Two: How Ceramic Insulators are Used

Ceramic insulators are found in various electronic applications, from power distribution centers to cell phones. Ceramics materials as insulation are due to their non-conductivity and exceptional mechanical strength. Some examples of ceramic insulators can be found on power lines, coaxial cables, and circuit boards to prevent electromagnetic (EM) waves, fire hazards, power surges, and short circuits. The wide use of ceramic insulators is due to their ability to hold heat. In addition, they are straightforward to manufacture and shape into a wide variety of configurations. In many applications, they are the central factor in keeping power under control.

Uses for Ceramic Insulators

Wire Support

Ceramic insulators are used to support wires on utility or phone poles. Wire support ceramic insulators have an umbrella-like design to protect wires and the lower part of the insulator from rain or snow. Ceramic wire support insulators are among the oldest types of ceramic insulators due to their ability to endure and withstand inclement weather.

Mechanical Tension

Mechanical tension ceramic insulators are designed for use in conditions where suspended wires or cables pull on the insulator. As with support ceramic insulators, they are used with overhead wires and radio antennas, and power lines. They can be placed between two power lines to keep them separated. Mechanical tension ceramic insulators are perfect for maintaining wires taut and straight.

Pole

Pole ceramic insulators include a spool insulator attached to a bracket, which is connected to the top and bottom of the spool by a small rod that passes through the middle of the insulator. They are attached to walls, poles, uprights, or surfaces by a bolt in the middle of the bracket. When the angle of the connecting line changes, pole ceramic insulators adjust and adapt to the change.

Safety

The main purpose of insulators is to control current flow and prevent it from moving toward the earth. Safety ceramic insulators stay put and supply insulation if wires are cut and fall to the ground. They are placed in such a fashion that they guarantee that wires will not contact the ground. Safety ceramic insulators are connected in different ways depending on the application's needs.

If a pole happens to fall, the ceramic insulator ensures that the lower part of the system does not have any voltage.

Low Voltage Distribution

Low voltage distribution ceramic insulators are installed vertically or horizontally using a bolt or on the cross arm. The design of typical voltage distribution ceramic insulators is similar to that of pole ceramic insulators. They are used in overhead lines with medium to low voltage.

The wide use of low voltage distribution ceramic insulators is due to their dependability and reliability.

Spark Plugs

Ceramic insulators on spark plugs force the spark to jump the gap to initiate combustion. High voltage has to move from one end of the spark plug to the other end in a spark plug. Ceramic insulation prevents flashover to the mass of the vehicle. The use of ceramic insulators in spark plugs is due to their high melting temperature and low thermal expansion.

Heat Applications

Ceramic insulators are widely used in applications where there is high heat. They support heating elements in ovens, heaters, and furnaces. Ceramic's resistance to abrasion and long life and its ability to hold its shape and size under pressure makes it the perfect insulation material for heated applications.

In many heaters, ceramic insulators support and separate heating elements.

Sleeve Washers

Electrical insulating ceramic sleeve washers, also known as shoulder or insulating washers, block electrical current and prevent galvanic corrosion. They have all the favorable properties and characteristics of typical ceramic insulators and can withstand temperatures of up to 3000°F. In addition, the special design of ceramic sleeve insulating washers makes them capable of resisting the effects of hydrochloric and nitric acid gases.

Leading Manufacturers and Suppliers

Chapter Three: Types of Ceramic Insulators

The many uses for ceramic insulators has made it necessary for engineers to design and develop ceramic insulator configurations to fit a wide assortment of applications. Though there are innumerable ceramic insulator uses, the number of types fall into a few basic categories.

The most commonly used types of ceramic insulators are pin, suspension, strain, and shackle. Beyond those four types are other varieties that provide similar functions but have certain detail differences.

Ceramic Insulator Types

Ceramic Corner Post

Corner post ceramic insulators are designed to withstand tension in a fence line caused by the fence pulling from its anchor point or changing directions. They are also used as fence line termination points. Corner post ceramic insulators come in various shapes and sizes to fit the application's needs and may have grooves for the insertion of wires.

Ceramic Strain Insulators

Strain ceramic insulators are designed to withstand the pull of suspended electrical wires or cables. They are used to support overhead antennas and power lines where there is mechanical tension. Strain ceramic insulators are installed between lengths of wire to isolate them on poles or towers.

The shape of strain ceramic insulators increases the space between cables and the load-bearing transfer capacity of the insulator. For radio antennas and power lines, strain ceramic insulators bear the physical tension of the wires.

Dog Bone Ceramic Insulators

Dog bone ceramic insulators are strain insulators used to mount electrical wires and insulate antenna wires. They have a ribbed construction to reduce radio frequency (RF) leakage. Dog bone ceramic insulators have a long body of two to three inches with perpendicular holes in either end. Ribbing is placed between the holes, as seen in the image below.

Additional resources:
Tips for Finding Glass Railroad Insulators? - Antique-Bottles.net
What is what is corona ring and Why Do We Use Them?
Isolator Selection Guide – dB Engineering

Want more information on powerline fuse? Feel free to contact us.

There are several types of materials used to produce dog bone insulators. Ceramic is chosen for its durability and extended usage life, which removes the need for constant replacement.

Hollow Ceramic Insulators

Hollow ceramic insulators are used for bushings for power and instrument transformers, wall bushings, circuit breakers, surge arresters, and cable terminals. They are produced in cylindrical, conical, or round body designs in various diameters. Hollow ceramic insulators are capable of high mechanical resistance and electrical insulation.

Lag Screw Ceramic Insulator

Lag screw ceramic insulators connect an electrical wire to posts to avoid losing energy to the post. The body of the ceramic insulator is attached to a wood screw for easy installation. Lag screw ceramic insulators are typically used on wood posts and have ceramic durability and strength, making them ideal for outdoor use along fence lines.

Multi-Groove Ceramic Insulator

Multi-groove ceramic insulators are a variation of insulators used on wood posts to fasten electrified wires without losing energy to the posts. They can be used with steel or aluminum wire and are exceptionally durable and dependable with superior insulating performance. The multi-groove post ceramic insulators design protects against arcing and loss of electricity. They are attached by placing a screw or nail down the center hole of the insulator.

Six Suspension Ceramic Insulators

Suspension ceramic insulators are hung from the cross arms of towers or other supporting structures to carry power conductors. The main parts of the rest of the ceramic insulators are the discs suspended on top of each other, referred to as a string. Metal links connect the strings of suspension ceramic insulators.

Standoff Ceramic Insulators

Standoff ceramic insulators prevent electricity from jumping between parts and confine current to the correct path. They are found in all kinds of situations but are commonly found as current regulators in transformers. Standoff ceramic insulators protect against power damage and reduce energy waste.

As with most ceramic insulators, standoff ceramic insulators can withstand high temperatures created by low-speed resistors. As a result, they are an excellent insulator for mounting fuses or heavy-duty cables and come in cylindrical shapes that are round, square, or rectangular.

Chapter Four: How Ceramic Insulators are Made

The purpose of ceramic insulators is to hold the electrified wire to avoid arcing, power loss, or connections between wires. They are sturdier than other insulating materials and do not break down in harsh and demanding conditions. The multiple types, designs, and sizes of ceramic insulators make them capable of fitting the needs of any application.

The process for making ceramic insulators includes porous clay that can be red, brown, or white. The insulators are formed using molds and shaping processes before being submitted to a heat treatment to solidify their structure.

The Making of Ceramic Insulators

Raw Material

The raw materials for the manufacture of ceramics cover a wide range of diverse and unique compounds because there are so many different applications for ceramics. For example, the production of insulators for high temperature and advanced electronics applications includes materials that contain carbon, nitrogen, silica, and sulfur.

Compression

The compression process can be dry or wet forming, with dry forming used for simple shapes, while damp forming uses extrusion or casting. For dry forming, the powdered material is placed into a flexible mold. Then, pressure is applied to compact the powder with sufficient force to create the desired shape.

Glazing

Depending on the manufacturer and the final application of the ceramic insulator, glazes may be added to the compressed component. These glasses add extra protection and increase the component's life span. In addition, a wide assortment of glazes can be added that are precision tested for endurance and strength.

Firing

The firing or drying of the shape is the most critical aspect of the process, as a part of the design and engineering of the component. Engineers account for any shrinkage that may occur during firing. As a part of firing, the glaze is baked onto the component's surface and hardened. Firing involves temperatures of 2850°F to 3100°F or 1570°C to 1704°C. The shrinkage factor is usually calculated at 20%.

The machining process works the component to meet the requirements of tolerance and design specifications. After the firing process, the compressed ceramic material is tough and requires diamond-tipped cutting tools. As with other aspects of the process, the amount of machining is dependent on the type of component. Tolerances are determined by the standards required for any device used for electrical applications.

Chapter Five: Leading Ceramic Insulator Machine Manufacturers

Ceramic insulators have become critical in our modern society. Luckily, there are many manufacturers of machines used to create ceramic insulators. Below, we feature five brands of machines used to produce ceramic insulators in the United States and Canada, along with specific models and their unique features:

SACMI USA Group

Model: PH Series Presses

Features: The PH Series Presses by SACMI USA Group are hydraulic presses designed for ceramic insulator production. These presses offer precise control over pressure, speed, and stroke, enabling the formation of complex ceramic shapes with high density. The machines feature advanced automation options, customizable pressing parameters, and compatibility with various ceramic materials.

L&L Kiln Mfg., Inc.

Model: Easy-Fire Ceramic Kiln

Features: The Easy-Fire Ceramic Kiln by L&L Kiln Mfg., Inc. is a versatile kiln used in the production of ceramic insulators. It offers programmable firing profiles, precise temperature control, and uniform heat distribution, ensuring consistent firing results. The kiln is available in different sizes and configurations to accommodate various production needs.

Harper International

Model: Pusher Furnaces

Features: Harper International specializes in pusher furnaces used in the production of ceramic insulators. These furnaces provide controlled atmospheres and high-temperature conditions necessary for the firing process. They offer precise temperature control, uniform heating profiles, and adjustable residence times. Harper's pusher furnaces are designed for high throughput and can accommodate various sizes and shapes of ceramic insulators.

Keith Company

Model: Rotary Kilns

Features: Keith Company manufactures rotary kilns used in ceramic insulator production. These kilns offer continuous, controlled firing processes. They provide excellent temperature uniformity, precise atmosphere control, and flexibility in terms of kiln length and diameter. Rotary kilns from Keith Company ensure consistent and efficient ceramic insulator production.

Ferro-Ceramic Grinding Inc.

Model: Precision Ceramic Machining Systems

Features: Ferro-Ceramic Grinding Inc. specializes in precision ceramic machining systems used in the production of ceramic insulators. These systems offer advanced CNC machining capabilities for shaping and finishing ceramic components with tight tolerances. They utilize high-precision tools, advanced control software, and custom fixturing options to achieve desired ceramic insulator specifications.

Please note that the availability and specific models may vary over time, so it's always recommended to check with the respective manufacturers for the latest product offerings

Chapter Six: Advantages of Ceramic Insulators

Since insulators are continuously exposed to atmospheric conditions, they must be strong and sturdy enough to withstand those demands. Insulators face many situations, including lightning strikes, pollution, bird damage, ice, snow, cold, exceptionally high temperatures, altitude differences, and other accidental and climatic demands.

The durability and strength of ceramic insulators have made them one of the most popular methods for protecting electric wires and lines. As a result, they are typically selected for use in crucial applications where longevity is required.

Ceramic Insulator Advantages

Hardness

It may seem that ceramic materials would not be hard enough to withstand constant use since they are made from powder. However, what is astonishing is that ceramic insulators are four times harder than stainless steel. This particular quality ensures their longevity.

Wear Resistance

In conjunction with ceramic insulators' hardness is their ability to retain their finish and appearance. Wear resistance and hardness go hand in hand to ensure resilience and durability, essential for sustainability.

Mechanical Properties

Any component required for the protection of electrical wiring has to retain its mechanical properties regardless of the conditions. Ceramic insulators are exceptionally capable of maintaining their mechanical properties to provide consistent functionality and dependability.

Dielectric Strength

This particular aspect of ceramic insulators is why they are chosen as a component for a variety of electrical wiring and circuits. Ceramic insulators have high dielectric strength and low electrical loss to provide excellent performance regardless of the conditions.

Resistance to Corrosion

Since ceramic insulators do not include any form of metal, they are resistant to the effects of rust and corrosion. As a result, they can be placed on fence posts, power pine crossbars, and other outdoor electrical lines and be unaffected by the ambient atmosphere.

Thermal Conductivity

Ceramic insulators increase in conductivity as the temperature rises but have a reduction in energy consumption.

Conclusion

• A ceramic insulator is a non-conductive insulator made from red, brown, or white porous clay that provides a bridge between electronic components and has high dielectric strength and constant and low electrical loss.
• The wide use of ceramic insulators began in the 1950s. They were cheaper to make and more resilient and lasted longer in harsh weather.
• Ceramic insulators are found in various electronic applications, from power distribution centers to cell phones. The choice of ceramic materials as insulation material is due to their non-conductivity and exceptional mechanical strength.
• The many uses for ceramic insulators have made it necessary for engineers to design and develop ceramic insulator configurations to fit a wide assortment of applications. Though there are innumerable ceramic insulator uses, the number of types falls into a few basic categories.
• The purpose of ceramic insulators is to hold the electrified wire to avoid arcing, power loss, or connections between wires. They are sturdier than other insulating materials and do not break down in harsh and demanding conditions.

Leading Manufacturers and Suppliers

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