Type of cable & wire, wire and cable different, Wire color code in India interview Question & Answer

Summary

This video provides a detailed explanation of wires and cables, focusing on common doubts related to them. It covers key differences between wires (which are uninsulated conductors) and cables (insulated wires), types of wires (solid and stranded), and various types of cables based on insulation, voltage, and conductor type. The video also discusses wire color codes used in India for single-phase, three-phase, and DC power supply systems. This comprehensive guide is useful for understanding wiring concepts and preparing for related interview questions.

Takeaways

• 🔌 Wires are conductors without insulation, commonly seen in high-voltage power lines.
• 🔧 Cables are wires with insulation, often used in household wiring for safety.
• 🧵 Two main types of wires: stranded (multiple thin wires) and solid (single, thick wire).
• 🛠️ Fuse wires are always solid and used in electrical safety devices.
• 🔋 Types of cables based on insulation: PVC cables, armored cables, and weatherproof cables, among others.
• ⚡ Types of cables based on voltage: low voltage, medium voltage, high voltage, and extra high voltage cables.
• 🧲 Conductors used in cables include copper and aluminum, with specific cables designed for high mechanical strength.
• 🌈 India’s color coding for insulated wires: Red for live, Black for neutral, Yellow for inverter, and Green for earth in single-phase systems.
• ⚙️ Three-phase systems use Red, Yellow, and Blue for different phases, with Black for neutral and Green for earth.
• 📊 DC power systems use Red for positive and Black for negative wires, commonly seen in electrical applications.

Q & A

What is a wire?

A wire refers to a conductor without any insulation. For example, the large power lines transmitting electricity from power stations to homes are uninsulated and thus considered wires.

What is a cable?

A cable is an insulated wire. The wire is covered with insulation, making it safer for use in households and other applications. Unlike bare wires, cables have protective layers.

How many types of wires are there?

There are two main types of wires: stranded wire and solid wire. Stranded wire consists of multiple thin wires twisted together, whereas solid wire is a single, solid conductor.

What is the difference between stranded wire and solid wire?

Stranded wire is made up of many small wires bundled together, making it flexible. Solid wire, on the other hand, consists of one single solid conductor, making it rigid and less flexible.

What are the common materials used for wires?

The two most common materials used for wires are copper and aluminum. These materials are chosen for their high conductivity.

What types of cables exist based on insulation?

Cables based on insulation include types like BIR cable, TRS and KET cable, PVC cable, and XLPE cable. Each type of insulation serves different purposes, such as waterproofing, flexibility, or heat resistance.

What are the voltage classifications for cables?

Cables can be classified based on voltage into low voltage, medium voltage, high voltage, and extra high voltage cables, depending on their application.

What are the common types of cables based on the number of cores?

Cables can be single-core, double-core, three-core, or even 3.5-core. For example, 3.5-core cables have three equal-sized conductors and a smaller neutral conductor.

What is the color coding system for insulated wires in India?

In India, the color coding for insulated wires is as follows: red for phase/live wire, black for neutral, green for earth, and yellow for inverter wiring. In three-phase systems, red, yellow, and blue are used for the three phases.

What is an armored cable?

An armored cable has an additional layer of protection made of steel or aluminum. This layer protects the cable from external damage, such as moisture, extreme temperatures, and mechanical impact.