Module 3

Question 1

A network of conductors and equipment designed to carry, distribute and convert electrical power safely from the point of delivery or generation to the various loads around the building that consume tthe electrical energy

Answer 1

Electrical system

Question 2

Basics of Electricity Distribution

Answer 2

1. Earthing and bonding
2. Electric Wiring
3. Industrial installations
4. Lighting controls
5. Lighting sources, lamps, lighting design
6. Telecommunication installations

Question 2

Basics of Electrical Installations

Answer 2

1. Lighting
2. Exhaust fans
3. Use of portable and non-portable electrical machines

Question 3

Types of Electric Power Distribution System

Answer 3

1. According to the nature of the supply
   »»AC Distribution System
   Primary Distribution System
   Secondary Distribution System

> > > > DC Distribution System

2. According to a type of construction
    Overhead system
    Underground system

Question 3

the power is distributed using two wires called Phase and neutral. The AC Power takes the shape of sinusoidal wave, the voltage peaks at 90 degrees during positive cycle and 270 during negative cycle

Answer 3

Single-Phase Power Supply

Question 4

Types of Electrical System in the Philippines

Answer 4

Three-wire 120/240V Systems
»>supplied with 240-volt, alternating current, 60-cycle power using two wire service drop
»>two 120 V AC load wires and single neutral

Two-wire 240V Systems
»>one 240V AC load wire, one neutral wire

Question 5

Design for household supplies and residential homes.
230V and 60HZ

Answer 5

Single phase connections

Question 6

Consist of three power wires
Depending the the type of circuit (Star and Delta)
AC Power Signal is 120 degrees out of phase with each other.

Answer 6

Three-Phase Power Supply

Question 6

Distribution Voltages

Answer 6

Primary: 4.16kV, 13.8, 34.5, 69
Secondary: 110/115V, 220/230V

Question 7

A type of alternating current that is commonly used in power generation, transmission and distribution.

> > Preferable for high tension power loads and up to 415V

> > type of polyphase system that used high three-wires and most common used for electrical grids around the world to transfer power.

Answer 7

Three-phase electric power

Question 8

Includes incoming power lines, an electric meter, a service panel, subpanels, household wiring, electrical boxes, receptacles (outlets), switches, and, of course, the appliances, lights, and equipment that put the power to work.

Answer 8

Home Electrical System

Question 8

Types of Protective Devices

Answer 8

1. Fure Wire or Fuse
2. Miniature Circuit Breaker
3. Earth Leakage Circuit Breaker
4. Earthing or Grounding
5. Ground-Fault Circuit Interrupter (GFCI)

Question 9

A device used to protect equipment, machinery, components and devices, in electrical and electronic circuit, against short circuit, over current and earth fault

Answer 9

Protective Device

Question 10

is a device that protects electrical systems against potentially dangerous power
surges and excessive temperatures.

Answer 10

Fuse

Question 11

is a metal box that contains screw-in fuses and cartridge fuses.

Answer 11

Fuse boxes

Question 11

Only one connecting plug, it can only break
one phase line, this switch is only suitable for controlling one-phase live wire.

Answer 11

1P - Single Pole

Question 11

it can only break
one phase line, this switch is only suitable for controlling one-phase live wire.

Answer 11

1P - Single Pole

Question 12

three are connected to
the live wires and the remaining is connected to the zero line. This switch is suitable for
controlling three-phase four-wire system circuit.

Answer 12

4P - Four Pole 1P+N

Question 12

A circuit breaker is one kind of electrical switch used to guard an electrical circuit against
short circuit otherwise an overload which will cause by excess current supply.

Answer 12

Miniature Circuit Breaker (MCB)

Question 12

which are connected
to the live wires. This switch is suitable for controlling three-phase 380V circuit.

Answer 12

3P - Three Pole

Question 13

3P+N

Answer 13

Three pole switches with zero terminal

Question 13

one is connected to the
phase line and the other is connected to the zero line.

Answer 13

2P - Two Pole

Question 14

1P+N

Answer 14

Single pole switch with zero terminal

Question 15

protects against overload, and short
circuit faults and is also used for switching the circuits. It can be used for higher current
rating and fault levels in domestic applications.

Answer 15

Molded Case Circuit Breaker

Question 15

It is another type of electrical protection device that is used when the load current exceeds the limit of a miniature circuit breaker.

Answer 15

Molded Case Circuit Breaker or Power Circuit Breaker

Question 16

can be used for protection of capacitor banks, generator protection, and main electric feeder distribution. It offers adequate protection whenever an application requires discrimination, adjustable overload setting, or earth fault protection. 100A and higher up to 100 kA

Answer 16

Molded Case Circuit Breaker

Question 17

is a safety device that notices a problem in your home power supply and then turns OFF in 10-15 milliseconds to stop electric shock.

Answer 17

Residual Current Device

Question 18

three types of RCDs based on the differential current they can handle.

Answer 18

1. High-sensitivity residual current devices 2. Medium-sensitivity residual current devices 3. Low-sensitivity residual current devices

Question 19

one kind of safety device used for installing an electrical device with high earth impedance to avoid shock. These devices identify small stray voltages of the electrical device on the metal enclosures and intrude the circuit if a dangerous voltage is identified.

Answer 19

Earth Leakage Circuit Breaker

Question 20

are generally installed where electrical circuits may accidentally come into contact with water. They are most often found in kitchens, bath and laundry rooms, or even out-of-doors or in the garage where electric power tools might be used.

Answer 20

Ground Fault Circuit Interrupter

Question 20

can help prevent electrocution. If a person’s body starts to receive a shock, it senses this and cuts off the power before he/she can get injured.

Answer 20

Grand Fault Circuit Interrupter

Question 20

is an integral part of any properly operating electrical system. In residence, grounding protects the occupants by providing a safe pathway for unwanted electricity that might otherwise create a hazard.

Answer 20

Grounding

Question 21

is used to provide a safe path for a fault current to flow

Answer 21

Grounding

Question 21

Grounding is usually done at two levels:

Answer 21

System grounding and Equipment grounding.

Question 22

is essentially a circuit designed to protect individual components of an electrical system.

Answer 22

Equipment Grounding

Question 22

Aims of Grounding System

Answer 22

- Limit the potential difference between metallic masses and ground. - Make sure the protection devices operate. - Eliminate or reduce the risk posed by a fault in the electrical equipment used

Question 22

two most popular methods used for grounding

Answer 22

electrode grounding water pipe grounding

Question 22

is a special circuit designed to protect the entire distribution system of a residence.

Answer 22

System Grounding

Question 23

is a long metal rod used for grounding that makes contact with the earth.

Answer 23

Electrode

Question 24

uses the underground metal pipe that supplies a residence with water and is typically the best electrical ground for a residential electrical system.

Answer 24

Water pipe ground

Question 25

are primarily in place to protect the outlet and surrounding area in case of an overload or power surge. I

Answer 25

Grounding Wires

Question 26

is the most widely used alternative source of power in facilities today. Its ability to provide continuous power as long as it has a supply of fuel makes it wellsuited for providing both long- and short-term backup power.

Answer 26

Diesel Generator