Earth Rods and Plates

In addition to the conductors outlined above, earth rods and plates or any combination thereof can be used to achieve an effective earth depending on the site conditions.

Earth rods take advantage of lower resistivity soils at greater depths than normal excavation will allow.

Earth plates are used to attain an effective earth in shallow soils with underlying rocks or in locations with large amounts of buried services. They can also provide protection at potentially dangerous places e.g. HV switching positions.

Вправа 3. Дайте відповіді на питання.

1. What is a groundbed?

2. How is it called each electrode?

3. What do you know about grounding systems?

4. What is cathodic protection?

5. What does Marconite provide?

6. What do you know about copper bond earth rods?

7. How can we apply earthing equipment?

8. What is the best earthing conductor?

9. What do you know about earth rods and plates?

Вправа 4. Перекладіть речення українською.

1. An effective earthing system relies on joints and connections to have good electrical conductivity with high mechanical strength.

2. Poorly chosen or badly installed joints and connectors can compromise the safe operation of an earthing system.

3. A simple, self-contained method of forming high quality electrical connections which requires no external power or heat source.

4. Connections are made using the high temperature reaction of powdered copper oxide and aluminium.

5. They will never loosen, are highly conductive and have excellent corrosion resistance.

6. Compression connectors produce very robust joints which can be buried in the ground or in concrete.

7. Where permanent connections are not appropriate, mechanical clamps offer the ideal solution.

8. These are typically used on smaller scale installations where periodic disconnection for testing is required.

9. All Furse mechanical clamps are manufactured from high copper content alloy.

10. They have high mechanical strength, excellent corrosion resistance and conductivity.

Вправа 5. Запишіть та вивчить технічні скорочення та одиниці вимірювання.

AC, ac (alternating current) змінний струм

AF (audio frequency) звукова частота

A (ampere) ампер

c (capacitance) ємність

cm (centimetre) сантиметр

cub (cubic) кубічний

dc (direct current) постійний струм

deg (degree) ступінь, градус

F (Fahrenheit) Фаренгейт

fig (figure) цифра, фігура (рисунок)

ft (foot) фут

HF (high frequency) висока частота

in (inch) дюйм

kg (kilogram) кілограм

km (kilometre) кілометр

kV (kilovolt) кіловольт

kW (kilowatt) кіловат

kWh (kilowatt-hour) кіловат-годин

lab (laboratory) лабораторія

lb (libra, pound) фунт

lg (length) довжина

lim (limit) межа

liq (liquid) рідина

meg (megohm) мегом

MeV (million-electronvolt) мільйон-електронвольт

MF (medium frequency) середня частота

mV (millivolt) мілівольт

mW (milliwatt) міліват

pc (per cent) процент, відсоток

psi ( pounds per square inch) фунти на квадратний дюйм

r (R) (resistance) опір

ref (reference) посилання

rpm (revolutions per minute) оберти за хвилину

VHF (very high frequency) ультрависока частота

V (volt) вольт

vol (volume) обсяг, об’єм.