Domestic Wiring Chapter 4

 Domestic Wiring Chapter 4 

TYPES OF CABLES

A brief description of the various cables used in domestic wiring is given here.

The main requirements ofthe insulting materials used for cable are :

✓ High insulation resistance.

✓ High dielectric strength.

✓ Good mechanical properties i.e. tenacity and elasticity.

✓ It should not be affected by chemicals around it.

✓ It should be non-hygroscopic because the dielectric strength of any material goes very much down with moisture connect.

Vulcanized Rubber

Rubber in its natural form is highly insulating but it absorbs moisture readily and gets oxidized into a resinous material; thereby it loses insulating properties. 

When it is mixed with sulphur along with other carefully chosen ingredients and is subjected to a particular temperature.

 It changes into vulcanized rubber which does not absorb moisture and has better insulating properties than even the pure rubber. 

It is elastic and resilient.The electrical properties expected of rubber insulation are high break-down strength and high insulation resistance. 

In fact the insulation strength of the vulcanized rubber is so good that for lower voltages the radial thickness is limited due to mechanical consideration.

The physical properties expected of rubber insulation are that the cable should withstand normal hazards of installation and it should give trouble-free service.

Vulcanized rubber insulated cables are used for wiring of houses, building and factories for low power work.

PVC (Polyvinyl chloride) cables

These are thermoplastic insulating materials and not used for high temperature as it gets softened and flows down to heat. 

These are therefore, not used for heating appliances. 

PVC is harder than rubber, hence a thin layer of PVC insulation is good enough. 

In fact, its thickness is decided by mechanical reasons rather than electrical. 

The PVC insulated cables are lesser in diameter as compared to TRS and more number ofwires can be placed in conduit as compared to TRS wires. 

These are used upto 1.1 kV voltages especially in concealed wiring system.

Tough Rubber Sheathed (TRS) or Cab Type Sheathed (CTS) Cables

This cable is used where humidity is high and it does not deteriorate even during long duration of exposure to moisture. 

As the name suggests these cables are provided with outer protective covering of tough rubber over normal insulation.

These are available as single, twin and three cores with an earth continuity conductor. These are used on 250/500 volt circuits.

 Lighting Control System 

is a networked collection of both small and big parts that enables users to enjoy distinctive lighting control features. 

Various components make up an automated lighting control system, depending on the features it provides. 

These often consist of touchscreens, light switches, occupancy sensors, and photocells. 

The ability to easily incorporate smarter components is the best feature of lighting control systems.

Systems for controlling lighting are used for the purposeful application of light to produce a desired aesthetic or functional impact. 

It consists of general lighting, accent lighting, and task lighting. 

The systems are frequently utilized in commercial, industrial, and residential areas for both indoor and outdoor lighting. 

They are also used to maximize the lighting system’s energy savings, adhere to building codes, or participate in energy-saving and green building initiatives. 

Lighting technology created for convenience, security, and energy efficiency may be included in lighting control systems. 

This could incorporate energy-efficient lighting fixtures and automated controls that adjust according to factors like occupancy or daylight availability.

Types of Lighting Control Systems

There are several lighting control options available, and understanding how they differ will aid in selecting the one that best suits your requirements.

Basic lighting controls

The manual on/off switch found in the majority of households is the most fundamental type of lighting control. 

To prevent electricity from being wasted, residents must manually turn them on as they enter a room and off when they depart.

Integrated lighting controls

Integrated lighting controls take this one step further if you thought aided lighting controls were clever. 

A wired or wireless connection is frequently used to centralize these systems within a house or place of business.

Assisted lighting controls

Your lighting plan can incorporate voice-activated assistive technology like Google Home and Amazon Alexa. 

This enables voice commands to turn on your lights, making it safer to wander around your house at night.

Motion sensor controls

Motion sensors are utilised for both security and utility illumination, and they are frequently confused with occupancy sensors. 

When motion is detected, they communicate with your lights to turn on, and then they quickly switch off.

Occupancy sensors

Occupancy sensors are very helpful for businesses since they automatically turn lights on when little movements are detected and turn them off after a predetermined amount of time. 

They use exceptionally high resolution and precision technology.

Dimmer switches

You have a tonne of freedom with dimmer switches. 

Instead of having pre-determined lighting configurations, you have complete control over how much light you want in the space, ranging from 0% to 100%. 

To make it easier to find the controls in the dark, some have a digital touch switch or a little light.