Installing a grounding system

Ex.4. Listen to the text and fill in the gaps.

Ex.2. Make up word collocations and translate them into Russian.

Grounding System Installations

Unit 7

The current leaving the train first passes into the running rails of the railway. The running rails are connected to one another and the electrification masts at regular intervals to create a distributed earth (ground) along the railway. This distributed earth enables current to pass from the rails into the greater mass of earth and in this way it maintains the rails close to earth potential. This limits the danger to personnel working on or about the railway.

For the same reason all metalwork which is exposed to touch and may become accidentally energised is also connected to the rails. Exposed metalwork may become energised due to an insulator flashover or by coming into contact with a broken energised conductor. The earthing system also ensures that, in the event of an electrical fault, the current is of sufficient magnitude to operate the protective relays of the railway and thereby open the appropriate circuit breakers to isolate the faulty section.

Ex.1. Answer the questions:

1. Why is grounding system important?

2. How does the grounding system work?

3. What risk can be presented by metalwork?

4. How can the grounding system help in the event of an electrical fault?

The current The rails The earth The personnel The metalwork The metal parts The faulty section

running leaving isolated distributed exposed working energised

by circuit breaks the train to touch by broken conductor on the railway along the railway in one direction

Ex.3. Before listening to the text below answer the questions:

1. Why is it important to ground wires?

2. What are safety rules when installing grounding system?

3. How does soil condition effect grounding installation?

soil, important, electricity, components, wire, condition, materials, grounding, install.

When installing a grounding system keep the basic components in mind. Consider the soil … where the system will be installed. You will have to create ditch to …. the system. The condition of the … will determine how you proceed with this step.

Consider the types of … you will use for the installation. A ground wire is a typical part of the system. Also, bonding wire and a footer are …. elements. A panel bond is necessary to connect the …. system to the electrical panel.

You must be aware of resistance between terminals. The continuous current of … must also be kept in mind. You should know the current level that will drive through a ….

Remember to avoid interference by keeping certain wires parallel to each other. Also, certain … must not be placed within its sphere of influence.

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