Module 3 Flashcards
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
Electrical system
Basics of Electricity Distribution
- Earthing and bonding
- Electric Wiring
- Industrial installations
- Lighting controls
- Lighting sources, lamps, lighting design
- Telecommunication installations
Basics of Electrical Installations
- Lighting
- Exhaust fans
- Use of portable and non-portable electrical machines
Types of Electric Power Distribution System
- According to the nature of the supply
»»AC Distribution System
Primary Distribution System
Secondary Distribution System
> > > > DC Distribution System
- According to a type of construction
Overhead system
Underground system
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
Single-Phase Power Supply
Types of Electrical System in the Philippines
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
Design for household supplies and residential homes.
230V and 60HZ
Single phase connections
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.
Three-Phase Power Supply
Distribution Voltages
Primary: 4.16kV, 13.8, 34.5, 69
Secondary: 110/115V, 220/230V
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.
Three-phase electric power
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.
Home Electrical System
Types of Protective Devices
- Fure Wire or Fuse
- Miniature Circuit Breaker
- Earth Leakage Circuit Breaker
- Earthing or Grounding
- Ground-Fault Circuit Interrupter (GFCI)
A device used to protect equipment, machinery, components and devices, in electrical and electronic circuit, against short circuit, over current and earth fault
Protective Device
is a device that protects electrical systems against potentially dangerous power
surges and excessive temperatures.
Fuse
is a metal box that contains screw-in fuses and cartridge fuses.
Fuse boxes
Only one connecting plug, it can only break
one phase line, this switch is only suitable for controlling one-phase live wire.
1P - Single Pole
it can only break
one phase line, this switch is only suitable for controlling one-phase live wire.
1P - Single Pole
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.
4P - Four Pole 1P+N
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.
Miniature Circuit Breaker (MCB)
which are connected
to the live wires. This switch is suitable for controlling three-phase 380V circuit.
3P - Three Pole
3P+N
Three pole switches with zero terminal
one is connected to the
phase line and the other is connected to the zero line.
2P - Two Pole
1P+N
Single pole switch with zero terminal
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.
Molded Case Circuit Breaker
It is another type of electrical protection device that is used when the load current exceeds
the limit of a miniature circuit breaker.
Molded Case Circuit Breaker or Power Circuit Breaker
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
Molded Case Circuit Breaker
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.
Residual Current Device
three
types of RCDs based on the differential current they can handle.
- High-sensitivity residual current devices
- Medium-sensitivity residual current devices
- Low-sensitivity residual current devices
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.
Earth Leakage Circuit Breaker
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.
Ground Fault Circuit Interrupter
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.
Grand Fault Circuit Interrupter
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.
Grounding
is used to provide a safe path for a fault current to flow
Grounding
Grounding is usually done at two levels:
System grounding and Equipment grounding.
is essentially a circuit designed to protect individual
components of an electrical system.
Equipment Grounding
Aims of Grounding System
- 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
two most popular methods used for grounding
electrode grounding
water pipe grounding
is a special circuit designed to protect the entire distribution system
of a residence.
System Grounding
is a long metal rod used for grounding that makes contact with the earth.
Electrode
uses the underground metal pipe that supplies a residence with water and is typically the best electrical ground for a residential electrical system.
Water pipe ground
are primarily in place to protect the outlet and surrounding area in case
of an overload or power surge. I
Grounding Wires
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.
Diesel Generator
