Circuit breakers are a vital part of home safety. A basic understanding of how a circuit breaker works will help you troubleshoot any electric problems and help you determine when it's time to call a professional.
The electric current that enters your home can be enough to kill a person without resistance. Appliances that connect to this current offer resistance that mitigates this current (this is only what makes the appliances work). The electric current enters the home through a hot wire and is channeled into the Earth through the neutral wire. The electric current, however, runs across the circuit meaning it rapidly changes direction.
The different electrical appliances, together they're called the "load," offer a constant resistance that keeps the current at safe levels. If one of these appliances overheats, it can melt the hot and neutral wires. When the two wires touch the resistance of the appliance no longer controls the current and the wires will grow hot and possibly lead to a fire. The circuit breaker detects this surge in current and opens the circuit, cutting the electricity to that appliance or area of the home.
Troubleshooting. One of the most common situations occurs when the electricity goes out in a certain area of the home but the breaker doesn't seem to have opened the circuit. A breaker switch can sometimes open a circuit without its mechanical handle flipping off. You should first try to manually switch the breaker off and then back on. It's also possible the current was interrupted somewhere other than the breaker due to faulty wiring. In this case, an electrician will probably need to come, run tests, and determine the nature of the open circuit and where the break has occurred. You should never attempt to replace a circuit breaker switch unless you have electrical expertise. Improperly replacing a switch can easily lead to much larger problems in your electrical wiring.
Fuses. Fuses are generally cheaper and have better response times than circuit breakers. They are also increasingly going out of fashion. Most homeowners prefer the convenience of circuit breakers that, unlike fuses, don't require replacements. Circuit breakers also create separate circuits for specific areas and appliances in your home, allowing you to retain much of your electrical power when a single circuit is tripped. Higher performance breakers use sensitive electromagnets. These breakers are competitive with the response time of fuses, cutting down on the risk of electrical sparks. Electromagnetic breakers tend to be more expensive.
Ground-Fault Circuit Interrupters (GFCI). While breakers will protect power surges in electrical wiring, preventing electrical sparks, but they do not prevent unintentional ground-faults that cause severe electrical shocks, burns, and lethal electrocutions. Electricity in your home has a bidirectional flow. This current should remain constant. When an exposed wire touches an appliance that appliance becomes electrically charged. If a person touches that appliance they create an intentional ground that causes the current to spike and begin to drain from the closed circuit into this new grounding. A GFCI detects this electrical drain and immediately opens the circuit. More than two-thirds of household electrocutions can be prevented by this inexpensive device.
Exercise 3. Translate the following words and word combinations into Russian
Home safety, to troubleshoot electric problem, to determine the nature, without resistance, to keep the current at safe levels, appliance, to melt the hot and neutral wires, to cut the electricity, to detect the surge in current, manually switch the breaker off, due to faulty wiring, to run test, to replace a circuit breaker, to attempt, electrical expertise, electrical wiring, cheap fuse, to have better response time, require replacements, a single circuit is tripped, tend to be more expensive, to be competitive with, on the risk of electrical sparks, power surge, unintentional ground-faults, lethal electrocutions, to remain constant, circuit interrupter.
Exercise 4. Find the English equivalents in the text
Сопротивление прибора, ослаблять ток, быстро менять направление, провод под напряжением, существенный, выключатели высокого качества, предотвратить искровые разряды, электропроводка, обнаруживать выброс тока, нагрузка, привести к пожару, электромагнитные выключатели, выявлять неполадки, неисправная проводка, неправильно, заменить выключатель, короткое замыкание на землю, смерть вследствие поражения электрическим током; определить, где произошло размыкание; прибор, время срабатывания плавкого предохранителя, прерывать, цепь выключена, удерживать электроэнергию.
Exercise 5. Answer the following questions:
1) Why should we understand the work of a circuit breaker?
2) Is the electric current that enters your home dangerous?
3) What do offer the appliances connected to the current?
4) Through what does the electric current enter the home?
5) What is the "load"?
6) What does the "load" offer?
7) What happens when one of the appliances overheats?
8) What happens when two wires touch?
9) What does the circuit breaker detect and what for?
10) What can you tell about troubleshooting? What is the most common situation?
11) Due to what the current can be interrupted?
12) What should do the electrician when the current is interrupted?
13) What are the main drawbacks and disadvantages of the fuses?
14) What are the drawbacks of the convenience of circuit breakers?
15) What are higher performance breakers competitive with?
16) What do the breakers prevent? What they do not prevent?
17) To what can unintentional ground-faults lead?
18) When does the appliance become electrically charged?
19) What can happen when a person touches the electrically charged appliance?
20) What is the task of GFCI?