ABSTRACT
This presentation illustrates the meaning of power surge , types , causes and possible solutions.
INTRODUCTION
Electrical surges are sudden, brief rises in voltage or current to a connected load. They may originate inside or outside any home or business. Standard household equipment operating at 220 volts can be damaged by surges of 500 volts or greater . Power surge is the greatest enemy of our appliances . When two current carrying conductors touches each other , the voltage drop and the current increases in order to Balance the power.
Power is the product of voltage and current.
power = v x I
Where v= voltage
I= current
p= power
The units,
power is in watt , voltage is in volt while current is in ampere .
Power surge can be classify into two : natural and artificial surge.
Natural source of power surge
Lightning is a large spark, or burst of electric charge, that travels through the air from one charged region of a cloud to another charged region. It occurs when one region of the atmosphere becomes highly, positively charged and another region becomes highly, negatively charged, or when a large charge difference exists between the bottom of the cloud and the ground. These large charge differences are caused by repeated collisions of small ice pellets, within the cloud.
When the charge differential becomes large enough, a bolt of lightning occurs, carrying electrical charge from one region to the other and neutralizing the charge differential. The lightning can occur between regions of the cloud, between the cloud and the surrounding air, or between the cloud and ground. As the lightning travels through the air, it heats the air to temperatures as high as 30,000° C (54,000° F). Thunder, the loud noise that accompanies lightning, results from the explosive expansion of the air as it is heated.
Paths of lighting into our home
Power surges can enter a home through several paths. Lightning can pass through the following paths:
1.Television cables.
2.Satellite dish cable.
3.Incoming telephone lines
4 The incoming electrical service lines. The most dangerous path is through incoming electrical service line.
LIGHTINING AND THUNDER STORM
ARTIFICIAL SOURCES OF POWER SURGE
• Tripped circuit breakers
• Short circuits
• Power transitions in other large equipment on the same power line
• Malfunctions caused by the power company
• Plugging in faulty power multiple socket
• Running a generator that isn't properly isolated from the commercial power system
Tripped circuit breaker
Circuit breaker is resettable fuse , used in protecting against unwanted current into our appliances . When the circuit breaker is set on 13 ampere ,once the current flowing into the circuit exceeds 13A ,the circuit breaker will trip off .the sudden power outage is known as power surge and can cause harm to our appliances and equipments.
Short circuit
Electrical circuit is path of wire and equipment along which an electric current flows . When two electrical service line bridged together , the voltage drops while the current increases , this is called short circuit. When it occurs , unwanted current flows into the appliances and destroy them.
Power transitions in other large equipment on the same power line
When any domestic wiring is feed from the same phase with an outdoor heavy equipment like wed machine , once the heavy equipment is switched on or off ,there must be sudden change in voltage or current which may cause damage to the domestic appliances.
Malfunction caused by the power company
There are many causes of power failure in an electric network ,they are fault at power station , damage to electric transmission lines ,over loading of electrical mains and tree limb creating short circuit in electrical line during storm . These listed above may cause tripping of the circuit breaker in a power station that result in power blackout to an area .it may cause damages in our appliances.
Plugging in faulty power multiple sockets
When any electrical appliance is plugged into a faulty multiple power sockets , they will be sparks . When this occur ,they may be a bridge between life and neutral wires which makes the voltage to drop while the current increases to infinity . this is one of the greatest enemy of our home appliances
surge protector
A surge protector (or surge suppressor) is an appliance designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe level.
The terms surge protection device (SPD), or the obsolescent term transient voltage surge suppressor (TVSS), are used to describe electrical devices typically installed in power distribution panels, process control systems, communications systems, and other heavy-duty industrial systems, for the purpose of protecting against electrical surges and spikes, including those caused by lightning. Scaled-down versions of these devices are sometimes installed in the appliance.
TYPES OF SURGE PROTECTORS
1.Fuse
2.Circuit breaker
3.overload relays
4.voltage regulation
5.lighting arrester
Fuse is a type of electrical and electronics device
used To provide over current protection of
either the Load or source
Plug and Fuse diagram
Circuit breaker
Circuit breaker is resettable fuse used in stopping unwanted current to flow into an electrical circuit.
0verload relays
Overload relay is a device used to protect electric motor from overload by disconnecting the power from the motor and stopping its operation . When an electric motor is rated 15ampere, the over load relay may equally be set in 15ampere to protect the motor but when the current exceed the rated value it trips off.
Voltage regulator
voltage regulator is the ability of a system to provide near constant voltage over a wide range of load condition . In electrical power system it is defined at the receiving end of a transmission line as:
Voltage regulation(VR)=V nl – V rated
V rated
WHERE : V nl =voltage at no load
V rated =voltage at full load
recommendations
• The rating of fuses in our plugs and multiple power socket , must be done properly.
• The setting of circuit breakers must also be done well.
• Before buying any appliance , we must check if it has a protection like having of fuse in plug of the wire that leads to the appliance.
• We must ensure that the lightning arresters are properly installed .
conclusion
Power surge is dangerous to our appliances and must be avoided and control with the listed protective measures above.
REFERENCES
Energy Safe Victoria. "Safety switches, surge diverters and circuit
breakers". Gas and electrical safety in the home. Energy Safe
Victoria. Retrieved 2016-05-04.
NIST. "Coordination
of cascaded surge-protective devices". Surge Protection in Low-Voltage
AC Power Circuits: An 8-part Anthology. NIST. Retrieved 2013-11-08.
Rosch, Winn (May 2008). "UL® 1449 3rd Edition" (PDF).
Eaton Corporation. Eaton Corporation. Retrieved 12 March 2016.