1. BLACKOUT POWER OUTAGE By Masih Madayeni Class 3/6 English Presentation

2. Tree limbs creating a short circuit in electrical lines during a storm. This typically results in a power outage in the area supplied by these lines.limbs A power outage (also power cut, blackout, or power failure) is a short- or long- term loss of the electric power to an area. There are many causes of power failures in an electricity network. Examples of these causes include faults at power stations, damage toelectric transmission lines, substations or other parts of the distribution system, a short circuit, or the overloading of electricity mains. Power failures are particularly critical at sites where the environment and public safety are at risk. Institutions such as hospitals, sewagetreatment plants, mines, and the like will usually have backup power sources such as standby generators, which will automatically start up when electrical power is lost. Other critical systems, such as telecommunications, are also required to have emergency power. Telephone exchange rooms usually have arrays of lead-acid batteries for backup and also a socket for connecting a generator during extended periods of outage.

3. TYPES OF POWER OUTAGE

4. Power outages are categorized into three different phenomena, relating to the duration and effect of the outage: 1.A transient fault is a momentary (a few seconds) loss of power typically caused by a temporary fault on a power line. Power is automatically restored once the fault is cleared. 2.A brownout is a drop in voltage in an electrical power supply. The term brownout comes from the dimming experienced by lighting when the voltage sags. Brownouts can cause poor performance of equipment or even incorrect operation. 3.A blackout refers to the total loss of power to an area and is the most severe form of power outage that can occur. Blackouts which result from or result in power stations tripping are particularly difficult to recover from quickly. Outages may last from a few minutes to a few weeks depending on the nature of the blackout and the configuration of the electrical network. 4.In the Philippines, the term brownout refers to a power outage, not to a drop in voltage.

6. Transient: lasting for only a short time and quickly coming to an end Temporary: having limited duration: lasting or designed to last for a limited time Fault: mistake: an error, especially in calculation Brownout: decrease in voltage Voltage: electric potential: electric potential expressed in volts

7. LARGE OR MAIN BRANCH OF A TREE