Surge supressor

SURGE SURGE SUPPRESSOSUPPRESSORR

Submitted byPRATYASHA PATRAELECTRICAL ENGINEERINGCOLLEGE OF ENGINEERING &TECHNOLOGYUnder The Guidance OfABHIMANYU MOHAPATRARANJAN KU. JENA

SURGESURGEPower Surge or transient voltage, is an

increase in voltage significantly above the designated level in a flow of electricity.

These transients attack the equipment through power input lines, signal input and output lines, data lines and any other wire coming into or going out of electronic devices.

It is the low intensity surge twice the nominal line voltage and relatively long in duration ,about one millisecond.

Damaging surges typically are shorter, measured in tens of nanoseconds, and much higher intensity, ten to twenty times larger than normal voltage.

SURGE SURGE SOURCESSOURCESLightningOperation of high power electrical

devicesFaulty wiringProblem with equipmentPotential error in distribution

system

Surge Surge SuppressorSuppressor Surge suppressor is a device inserted in alternating

current(AC) utility lines which typically used to protect electronic equipment from damage or destruction cause by transient voltage and surge current.

A typical surge suppressor is a small box with several utility outlets, a power switch and a 3wire cord for plugging into a wall outlets.

..Need for surge Need for surge suppressorsuppressor

The electronic equipment containing transistor ,integrated circuit are vulnerable to damage by transients over voltages on AC supply mains.

In the absence of surge suppressor , the transient over voltage may have as high as 6kv .these pulses are of short duration and measured in microsecond ,can destroy transistor ,integrated circuit and sensitive component.

The Process of The Process of ProtectionProtection A standard surge protection passes the

electrical current along from the outlet to a number of electrical and electronic devices plugged into the power strip. If the voltage from the outlet rises above the accepted level- the surge protector diverts the extra electricity into the outlet’s grounding wire.

In the most common type of surge protector, a component called a metal oxide varistor, or MOV, diverts the extra voltage,

MOV forms a connection between hot power line grounding line

MOV has three parts: a piece of metal oxide material in the middle, joined to the power and grounding line and two semiconductors.

Working of MOVWorking of MOV These semiconductors have a variable resistance that

is dependent on voltage. When voltage is below a certain level, the electrons in the semiconductors flow in such a way as to create a very high resitance.When the voltage exceeds that level, the electrons behave differently creating a much low resistance. When the voltage is correct, an MOV does nothing. When voltage is too high an MOV can conduct a lot of current to eliminate the extra voltage.

As soon as current is diverted into the MOV and to ground, the voltage in the hot line returns to a normal level, so the MOV’s resistance shoots of again. In this way, the MOV only diverts the surge current while allowing the standard current to continue powering the machines connected to the surge protector.

Surge Surge connectionconnectionA series connected surge

suppressor It act as a roadblock. The surge must travel through

the suppressor on its way to our equipment. The suppressor removes or smoothes out the surge on its way. So no voltage are left to harm our equipment.

A parallel connected surge suppressor

It is connected in parallel to the computer across the leads of the power line just as the computer. The surge suppressor works by shorting out the surge, routing its high voltage direct from hot to neutral , before the surge voltage on the power line rises to a point at which can damage our computer.

Installation Installation LocationLocation A series connected surge suppressor must be located

between the source and our computer . A parallel connected surge suppressor could be

located any where in an electrical circuit as long as it can provide a lower resistance path to ground than the circuit of our computer’s power supply.

Most common surge suppressor takes the form of outlet strips function ay the device level or at the point of use as described in industry. They are meant to protect only a single device or few devices.

Whole premises or whole house surge is install in our fuse box or breaker panel. It has the advantage that they protect everything in our office and home against external surges.

Advance Surge Advance Surge SuppressorSuppressor

Voltage Signal Surge Suppressor

AC Surge Suppressor

Voltage Signal Surge Voltage Signal Surge ProtectorsProtectors Description: These are a line of transient

surge protection devices used in one way unipolar (bipolar) systems.

It requires a remotely located transducer. This result in transmission wire being connected between the transducer and data acquisition system, acting as a signal carrier as well as the transient voltage and surge current carrier.

WorkingWorking

It has a line side which is connected to the transmission wire and a protected side which is connected to the sensitive equipment.

It provides three stage of protection for signal path.

Stage 1: The input of the module includes an inductor which slows

down rise time of the transient and provides an impedance mismatch resulting in some of the transient energy being reflected back down the supply lines.

Stage 2: In this stage tight voltage clamping is provided. Stage 3: In this stage protection is provided by MOV which suppress large

surge current and clamp the larger spikes. All destructive voltages and currents are absorbed into an earth connection.

FeaturesFeaturesTight clamping voltage High surge current handling

capabilityLow series resistance Very high resistance during normal

operation100% redundancy

AC Surge AC Surge SuppressorSuppressorDescription: These are a line of transient

surge protection devices used in single phase AC supply voltage application. These devices are design to provide protection for electronic equipment requiring connection to an AC supply.

WorkingWorking It has a line side which is connected to the AC supply LIVE and NEUTRAL

and a protected side which is connected to the sensitive equipment. It provides three stage of protection for signal path. Stage 1: The input of the module includes an inductor which slows

down rise time of the transient and provides an impedance mismatch resulting in some of the transient energy being reflected back down the supply lines.

Stage 2: In this stage protection is provided by MOV and a thermal

fuse. The MOV suppresses large surge current and clamps voltage spikes that just above the maximum supply tolerance level. Once the MOV reaches the end of its useful life, the thermal fuse blow, the MOV will removed from the circuit, and the green LED will be extinguished. This MOV accounts for appx 12% of surge protectors total protection capacity

Stage 3: In this stage protection is provides the remaining 88% of

protection capacity in the form of an arrays of MOVs.The LIVE and NEUTRAL are protected individually as well as differential mode.

FeaturesFeaturesTight clamping voltage High surge current handling

capabilityVery high resistance during normal

operationLED indicator ensures continued

protection100% redundancy

Surge Suppressor Surge Suppressor RatingRating Peak surge current

This represent the maximum transient current that the suppressor can handle during a surge.

Joule rating It is a measurement of energy absorption capability of the surge

processor Response time It tells at what time delay they respond to the power surge.

Clamping voltage It tells what voltage will cause the MOVs to conduct electricity to

the ground line.

LimitationLimitation Continues conduction of the varistor make it hot. At somewhere lower power dissipation in the varistor, the varistor may become hot enough to melt plastics in the vicinity of the varistor.In some cases flammable plastic might be ignited by hot varistor.

ConclusionConclusionSurge suppressors should be used as a matter

of habit with all semiconductor based electronic and computer hardware including peripherals such as printers monitors, external disk drivers and others. But it can’t be relied upon to provide protection against lightning induced transients. So the safest procedure to ensure that all susceptible hardware is to unplug the suppressor main power cord during lightning.