Why should you have an Earthing System?

1. Safety for Human Life, Electrical Devices and Buildings

It saves the human life from the danger of electrical shock which can cause death, by blowing a fuse. It protects your electric equipment or devices.

It provides a safe path for lighting and short circuit currents and saves the building from structural damage.

2. Voltage Stabilization

Electricity comes from many sources, every transformer can be considered as a separate source. If there is no point which will act as a common point, then it is impossible to make a calculation between these sources.

In an electrical distribution system, Earth is the omnipresent conductive surface, which makes it a universal standard for all-electric systems.

3. Over Voltage Protection

Earthing System provides an alternative path in the electrical system to minimize the dangerous effect in the electrical system which happens at the time of lighting and unintentional contact with high voltage lines.

Methods of Earthing:

1. Plate Type Earthing

You need to have some basic components, a cast iron plate or a copper plate. The plate is buried 8 feet into the ground with bolts in a vertical position.

2. Pipe Type Earthing

Earthing electrode pipes, these can be used in homes, offices as well as power stations.(2.5 M LENGTH 38 MM DIAMETR)

3. Rod Earthing

This type of earthing is same as pipe earthing. Rods can be of copper or galvanized iron.The length of the rod should be approximately 2.5 M (8.2 ft), which will be buried in the earth vertically.

4. Earthing through Waterman

In this type of Earthing, you need galvanized iron pipes. Before using these pipes, make sure that resistance is good.

5. Strip/ Wire Earthing

This type of earthing has strip electrodes of cross-section not less than 25mm x 1.6mm in case of copper and 25mm x 4mm of Galvanized Iron buried into a horizontal pit of a minimum depth of 0.5 m.

This type of Earthing is best in rocky soil as in these places it is difficult to do plate type earthing.

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What is a grounded system?

Grounding is a method of giving electricity the most effect way to return to ground via the service panel. You see current flows from the panel to the outlet or device to power it up. The neutral wire is the return path for unused current. The ground wire is an additional path for electrical current to return safely to the ground without danger to anyone in the event of a short circuit. In that instant, the short would cause the current to flow through the ground wire, causing a fuse to blow or a circuit breaker to trip.

What Is the Purpose of System Grounding?

System grounding, or the intentional connection of a phase or neutral conductor to earth, is for the purpose of controlling the voltage to earth, or ground, within predictable limits. It also provides for a flow of current that will allow detection of an unwanted connection between system conductors and ground [a ground fault].

What is a ground fault?

A ground fault is an unwanted connection between the system conductors and ground. Ground faults cause serious damage to equipment and to your processes. During a fault condition, equipment can be damaged and processes shut down.

Dangers of an Ungrounded Appliance

An ungrounded electrical box, appliance, power tool, or extension cord could become a danger if there is no path to ground, except through you. You see, without a ground wire, your body may complete the ground path and you may be shocked or electrocuted.

Билет 25

1) Each aircraft has a transmitters and receivers for transmitting and receiving radio signals to other aircraft or the ground.Speech recorded through the microphone. The aircraft also installed airplane's intercom system to communicate to the pilot with the crew or with passengers. To transfer any important messages( emergency , change of course, and the like). Airspeak is a special variant of the English language, created on the initiative of the international civil aviation organization (ICAO) after world war II. Airspeak was created to ensure that the radio communications between pilots and air traffic controllers was the most clear and contained no ambiguity. In other words, participants ' communication air traffic should not be very long sentences, and using grammar, vocabulary and pronunciation as well as the specialized terminology only in accordance with the rules of the English language.

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