application guide for surges

8/4/2019 Application Guide for Surges

1/15Bowthorpe Low Voltage Division Tel: +44(0) 1273 692 591 Fax: +44 (0) 1273 676 637 e-mail: [email protected]

A Guide to

Lightning andSurge Protection

A Guide to

Lightning andSurge Protection

to BS6651: 1999 Annex C


2/15

Contents

What are surges, transients and spikes? 3

Who should read this guide?

Who are Bowthorpe? 3

What can Bowthorpe offer you?

Surges 4

What is a surge? Where do surges come from? Surges, transients, spikes - whose problem are they?

Lightning6

Direct Coupling Earth Voltage Inductive Coupling

Risk Assessment within BS6651 7

What the insurers say! 8

Commercial considerations

BS6651: 1999 Annex C - Co-ordinated Protection9

The Co-ordinated Protection Strategy 10

Its cheaper than you think How do surge protectors work? Design considerations

Product Selection Guide 11-14

AC Power Systems Network and Telecom Systems

Product selection diagram

Telecommunication and wireless protection systems

Questions and Answers 15

Common Misconceptions 15

Page

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3/15

odays business environment is a

world dominated by computers.

Every aspect of our working lives

depends on the efficient functioning of

critical IT systems.

For many companies, disruption of the IT

system impacts heavily on the day to day

health of the organisation. Should

damage occur, the cost can be severe, in

some cases, catastrophically so.

Clearly, the responsibility to prevent such

a disaster occurring can lie with several

people within the company. In some

cases, external bodies such as the

companys insurer may be the driving

force to implement an effective protectionstrategy.

The objective of this guide is to

familiarise you with the basics of surge

protection, allowing you to effectively

counter the threat posed by lightning and

surges to the life of your business.

owthorpe is an internationally

recognised, ISO9001 registered,

specialist manufacturer of surge

protectors for Mains Power, Voice and

Data Systems. We have representatives

on various international committees

including the IEC SC37A sub committee,

which is responsible for developing the

worlds first truly international surge

protection standard, IEC 61643

This application guide is designed for

consultantsdesignersspecifierscontractorsend usersusers of electronic systemsinsurersIT managersfinance directorsfacilities managers

telecom managerstechnical and non-technical

people.

It will enable you to select the

appropriate surge suppression

equipment to fit any particular

application and will provide an insight

into the phenomena of surges, what

causes them and how to stop them.

Technical hotlineSite surveysConsultancy advice

Comprehensive product rangeState of the art technologyCompetitive pricesSpecification of individual

products and complete protection

systems

Factory and laboratory visits,witness tests

Professional CPD accreditedpresentations

Training seminars

Who should read

this guide?

What are surges, transients and spikes?

Who are Bowthorpe?

What can Bowthorpe

offer you?

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4/15

surge, also referred to as a spike,

glitch or transient overvoltage, is

a very short timescale deviation

from the normal operating voltage of an

electrical system.

Typically lasting tens of micro-seconds,

surges can reach values of several

thousands of volts, thus making them

Voltage

Surges

20msTime

Voltage

50s

8/20s surge (enlarged in time)

Time0 0

Small surges can cause... Spurious crashing of computer

equipment

Corruption of data transfer over

networks

Unexpected printer output

Gradual component degradation leading

to equipment breakdown

Internally generated surges occur on a

daily basis and can be easily

suppressed utilising surge protectors in

the form of plug adaptors, socket strips

or in-line units.

In some cases, Radio Frequency

Interference (RFI) filtering is incorporated

within these protectors. RFI, or noise, is

rarely damaging to equipment but can be

an annoyance if experienced regularly.

Far more damaging to equipment and

systems are the large spikes typically

generated externally to the building and

normally associated with lightning activity,

Surges

What is a surge?

Where do surges come from?

ost surges are caused by an

electrical load either within or

outside a building being switched

on or off. Particular causes of transients

include large machines, lift motors,

welding machines and large printers.

Fortunately, most internally generated

transients tend to be reasonably small

(typically only a few hundreds of volts)

and consequently their effects range from

the short-term: data corruption, system

crashes and lock-up, to the long-term:

insiduous component degradation which

is a major factor in system reliability

assessments.

particularly damaging for computer

related equipment.

Most surges occur on the mains supply,

but they also pose a real threat to any

system utilising copper communication

cables, such as a Local Area Network

(LAN) or telephone systems.

Where do surges

come from?

Inside the Building

Factory equipment Office equipment

Air conditioning and lift motors

4

What is a surge? A surge is a short transient deviation of line voltage from the nominaloperating level.

Most surges occur on

the mains supply but

they also pose a real

threat to any systemutilising copper

communication cables

Far more damaging

to equipment and

systems are the

large spikes



5/15

Large spikes can

lead to...

Failure of computer power circuits

Failure of communication interfaces

Irreversible damage to hardware

electricity supply faults or switching of

large loads within the power distribution

network (National Grid/ Regional

Electricity Companys [RECs]).

Large transients, such as those caused

when there is a nearby lightning strike,

can reach values of 6000 Volts and

Since all types of transient disturbances

can be transported via electrical wiring,

nearly all electronic equipment, from

telephones and fax machines to large and

expensive computer systems, are at risk.

The extent of damage sustained ranges

from corrupted data communication toimmediate physical destruction of hard-

ware and, in some cases fire risk or even

5

Where do surgescome from?

The Outside World

Lightning

Transformer tap switching, power

station, sub-station and distribution faults

Power cross faults

Low quality generators

3,000 Amps inside a building.

Surges of this magnitude can cause

extensive damage to computer circuitry,

literally blowing up sensitive components

such as micro-chips and in some cases,

causing fire within computer or

communication equipment.

compromised human safety.

You may even have already suffered

equipment failure through surge damage

without even knowing it! The cause of a

computer breakdown often passes

unknown with the computer being simply

replaced or repaired. Component fatiguedue to repeated transient attack goes

unnoticed until its too late.

Everyones (including yours!)

Surges, Transients, Spikes - whose problem are they?

Bowthorpe supply a wide range of surge protection products to suit all needs



6/15

assessment which establishes the

prominence of the building given its

geographical location.

The purpose of a structural protection

system is to prevent damage to the fabric

of the building, prevent risk of fire and

safeguard personnel from the dangers of

inadvertent electrical shocks.

From the perspective of structural

protection for the building, a lightning

strike to the surrounding area is of no

consequence. However, from the point of

view of surge protection of equipment

within the building, nearby lightning

strikes are as important as direct strikes.

The reason for this is that a structural

protection system is dealing with the

primary effects of the lightning strike,

whereas surge protection is dealing with

the secondary effects of lightning.

The following diagrams portray three

important mechanisms by which lightning

strikes can affect sensitive equipment.

y far the most prominent cause of

damaging transients is nearby or

even direct lightning strikes.

Lightning discharge currents can be as

high as 200,000 Amps in the UK, with

the average discharge current being

28,000 Amps.

Obviously, such massive currents would

vaporise any electronic equipment or

cabling in the case of a direct strike to a

cable.

Fortunately, this situation is rare as most

equipment and cabling is located within a

building. Lightning will always tend to

strike the most prominent feature, which

is invariably the roof of the building!

The British Standard for Lightning

Protection : BS6651:1999 goes into great

detail on the whys and wherefores of

designing and installing a structural

protection system (lightning conductors)for the building. The decision as to

whether to install a structural protection

system is essentially based on a risk

6

Lightning

Direct Coupling

Direct Coupling

The bulk of the discharge current from a

direct strike to a power conductor pylon,

for example, will be conducted to earth.

Some proportion of the discharge current,

however, will be conducted as a surge on

the cable. The magnitude of the surge

current varies due to the length and type

of the cable as well as the magnitude of

the lightning strike.

Sensitive equipment can therefore be

damaged even when the lightning strike

is some distance away.

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7

Inductive Coupling

Earth Voltage

Earth Voltage

Inductive Coupling

200

2000

400

400

600

600

800

1000

1200

NationalGridNorthing(km)

National Grid Easting (km)

During a cloud to ground lightning strike,

the strike point is raised to a very high

voltage owing to the large current (up to

200kA) being conducted through the

ground (which has a finite resistance).

Typically this value could be in the

hundreds of thousands of volts for a

fraction of a second. The further away

from the strike point, the lower the

voltage value. Depending on local soil

conditions and climate, this voltage

disturbance can be significant up to about

2km away.

As a consequence of this earth voltage

disturbance, any building within 2km of a

lightning strike will experience a

fluctuation of its mains earth voltage.

Because the equipment within the

building may be connected to other

electrical systems, such as equipment in

another building, the electricity sub-

station etc., there exists a situation where

A current carrying cable, by virtue of its

electromagnetic field, will induce a

current flow in any nearby cable running

parallel to it.

the power and data cables entering the

building may experience different earth

voltages at each end. This causes a

current to flow in the connected electrical

wiring which is perceived by the

equipment as an incoming surge.

Risk Assessment within BS6651

ifferent areas of the country and

the world experience higher

levels of lightning activity than

others, and the climate largely

determines the overall trend. Many of the

variable factors are built into the risk

assessment procedures in BS6651.

The risk assessment for structural

protection is essentially determining how

prominent the structure is and therefore

how attractive it is to a lightning strike.

The risk assessment for surge protection

is more complex. As well as determining

how vulnerable the building is to a direct

strike, the risk assessment takes into

account the quantity of external cables

entering the building and the nature of the

equipment within the building as this

determines the Consequential Loss factor

should a system be affected.

Although the risk assessment procedurecan be a little complicated, with care it can

be a powerful tool to establish a realistic

appraisal of the risk to a system.

This basic electrical phenomenon is

responsible for the third mechanism of

lightning associated surges. A cloud to

cloud lightning strike, of which there are

approximately up to 1 million a year in

the UK, sets up a massive

electromagnetic field. Any cable which

lies within this field is subject to the

electromagnetic forces of it. Induced

currents are created, especially prevalent

where there is a large network of cables

above ground. Lightning strikes to nearby

pylons, trees etc produce similar results.

Map showing thunderstorm days per year throughout the world

90

80

70

60

50

40

30

20

10

0

10

20

30

40

50

60

70180 150 120 90 60 30 0 30 60 90 120 150 180

4060

40

40

60

80

60

60

80

30

5

5

5

20 20

10

1040 140

140

100

100

80

402010

20

60 60

5

10

100 120

40

60

4020

10

5

1

20

10

10 140

140

140

120

80

80

180180

100

60

60

10

40

5

5

1

30 20

10

1

140

5

3040

20

605

20

100 20

40

8040

80

5

10

1

405

520100 10

Number of lightning flashes to the groundper km2 per year for the uk

Extracts from BS6651 are reproduced with the permission of BSI. Complete editions of the standards can be obtained by post fromBSI Customer Services, 389 Chiswick High Road, London W4 4AL.

NOTE: This map is based on information from the World Meteorological Organisation records for 1955.

0.1 0.4

0.2 0.5

0.3 0.6

The lightning density map was compiled byElectricity Association Technology Limitedfrom data accumulated over four years fromits Lightning Location System.

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8/15

What the Insurers Say!

Commercial Considerationsowadays, with the ever increasing

amount of information technology

being used for businesses, the

costs of equipment repair and replacement

have become a major concern for theinsurance companies.

In some cases, they have provided the

finances to replace computer systems

worth some 100,000s that have been

destroyed by lightning or other surge

phenomena. Downtime and other

consequential losses often cost far more

to replace. Many other cases occur in

domestic and small business applications

where equipment worth 100s or 1,000s

has been damaged.

The insurance companies now recognise

surge protection as being a solution to

this problem. They know that a total

protection system can be fitted for

a fraction of the equipment

replacement value.

8

Latest statistics on claims

for hardware and

consequential loss have

astonished insurers to such

a degree that they have had

to reassess premiums for

any company heavily reliant

on information technology.

An organisation that has taken BS6651

very much to heart is the Loss Prevention

Council, or LPC. The LPC is funded by

the Association of British Insurers and

Lloyds of London and is involved in all

aspects of loss prevention and risk

control on a world-wide basis. It is,

therefore, the body that the insurers refer

to for guidelines when drawing up their

insurance policies and assessing

potential relatively new risks.

BS6651: 1999 Annex C has been taken

very seriously by the LPC and, in turn,

the insurance companies, particularly inlight of recent avoidable claims for

computer hardware damage and

consequential loss as a result of surges,

spikes and transients.

LPC statistics on claims for hardware and

consequential loss have astonished

insurers to such a degree that they have

had to reassess premiums for any

company heavily reliant on information

technology. A single such claim for over

0.5 million to one insurer has certainlyfocused the insurance industrys

attention to this subject. It is now

becoming the insurers policy to

either demand higher premiums or

even refuse cover if the

recommendations of BS6651 are

not acted upon!

The statistics reveal that 60-70%

of commercial claims could be

directly attributed to computer

hardware failure andconsequential loss due to

surge disruption or damage.

Clearly, no organisation

appreciates higher insurance

premiums, but, equally, no

successful company can

accept computer failure

resulting in poor customer

service.



9/15

he British Standard BS6651:

1999 is titled Code of Practice

for Protection of Structures

Against Lightning and outlines the

general principles of applying lightningprotection to buildings and structures.

It was in 1992 that Appendix C

(changed to Annex C in the 1999

revision) was originally incorporated

within BS6651 and provided general

advice on protection of electronic

equipment within or on structures against

lightning. BS6651: 1999 Annex C

gives details on the following aspects

of surge protection:

How to assess the lightning exposurerisk to equipment

Routes along which surges can entera building and where they go within

the building

Deciding factors for installing protection Recommended levels of protection in

a co-ordinated protection system

AC Power Protection

For AC power, Annex C defines three

different categories of surge protection

that vary in surge handling ability,

each designed for installation at

particular locations within a building

supply network.

Category C - The supply side of theincoming distribution board

Category B - The mainsdistribution system

Category A - The load side ofsocket outlets

Although not confirmed in BS6651, these

three categories reflect with the location

categories used in the American standard

IEEE C62.41 (1991).

Each BS6651 location category is divided

into three groups which suit different

exposure or lightning risk levels. These

are known as the low, medium and high

system exposure levels.

Bowthorpe products are suitable for the

high system exposure level of each

category and also address the lower

exposure levels. By designing our

products in this way, we greatly simplify

product selection.

The surge ratings for each location

category are the peak surge voltage and

peak surge current that will normally

occur at that location in the supply network.

Any protection device designed for

these categories must be able to

withstand the respective peak surge

current and voltage. The following

table indicates the protection levels

required for the high system exposure

group of each category.

Network & Telecom

System Protection

Annex C also defines a location

category C for communication

systems which specifies a 10kA

protection level. However, communication

cable exhibits a higher electrical

impedance that helps to dissipate the

surge energy.

In communication systems, therefore, as

long as category C protection is fitted, it

is not normally necessary to protect

against incoming surges at location

categories B and A.

BS6651: 1999 Annex C. - Co-ordinated Protection

9

Location category C B A

Peak surge voltage 20kV 6kV 6kV

Peak surge current 10kA 3kA 500 A



10/15

By carefully selecting which parts

of the computer system are mostcritical to your business operations,

implementing total protection need

not be very costly and will easily be

within the reach of small and large

businesses alike.

A risk assessment should be performed

to identify key equipment and to

weigh the costs of protecting this

equipment against the potential losses

to the business in system downtime,

maintenance and reduced performance.

The Co-ordinated Protection Strategy

Its cheaper than you think How do Surge Protectors

work?

Different kinds of protector use differenttypes of components or combinations

thereof to suppress surges, transients

and spikes.

As described earlier in this guide, a surge

is a rapid fluctuation in voltage occurring

on a signal or AC power cable which, in

many cases, will contain enough energy to

cause disruption to communications and

often physical damage to electronic circuitry.

The suppressor components used are

normally one of three basic technologies:

gas discharge tubemetal oxide varistorsolid-state semi-conductor.

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11/15

To be effective, surge protection must

survive the maximum transient

overvoltages and resultant currents that

occur at the different locations and only

pass the residual part of the surge that

will not cause damage.

It is therefore necessary to know the

equipment transient design level

(ETDL) for the equipment to be

protected. This is the maximum surge

voltage level that will not impair the

performance of the equipment and is also

known as the immunity level. The

residual part of a surge which passes

through the protector is known as the

let-through voltage or transient control

level (TCL).

For protection to be effective, the TCL

must be less than the ETDL and include

a reasonable safety margin Vm:

TCL+Vm


12/15

12

Plug-in mains protection products

MDSP DIN rail mount replaceable modules

Network Barrier & Telecom TLP Series

Network and Telecom

Systems

6651C Protector Step 1: Location Category C

Locate all communication cables

entering the building including PSTN

dial-up voice lines and leased lines,

ISDN and network lines. All incoming

cables that carry signals on wire

conductors must be fitted with

appropriate category C protection from

Bowthorpes extensive range of

datacom, telecom and network barriers.

Step 2: Location Category B

Identify sub-distribution panels that

supply mission-critical hardware such as

mini-computers, PABX systems,network file-servers and mainframes.

Install the location category B protection

described below.

With the increasing use of distributed

networks, many users prefer to protect

all sub-distribution panels with these

economically priced products.

Step 3: Location Category A

Fileservers, mainframe computers,

PABX, and other such hardware are

important for providing critical services

to the company and should, therefore,

be fitted with category A protection.

Our range of plug-in devices and

socket strips provide fine-tuned,

backup protection for the most

important equipment and will suppress

surges and interference from inside

the building.

Category C Products

Network Barrier & Telecom

TLP Series

10kA rated barriers are available in DIN rail

mounted format for datalines. For telephone

PABX systems, Krone mounted units are

available in 10-line and single-line variants.

Category A Products

Protector Plugs and

Adaptors

This range of single-outlet surge

suppressors and hardwired plugs are

available with surge only protection and

various ratings of RFI filtering. UK,

French and German formats are offeredand all units feature thermal protection

against surges exceeding their rating,

unlike most low cost products.

Socket Strips

These AC mains socket strips are

available in UK, French and German

formats with options for surge protection,

RFI filtering and a choice of from four to

ten socket outlets. All strips feature

thermal protection.

Category B Products

6651C ProtectorA compact, hard-wired, panel mounting

protector for sub-distribution panels

available in single and three phase models.

Spur Protector

Ideal for the protection of equipment on

individual ring mains, this unit can be

either wired to equipment as an inline

protector or can be hardwired into wall

mounted conduits.

DSP1 and DSP3

General purpose, hard-wired, single and

three-phase distribution panel protectors

with 30kA of surge capacity. Optional

relay contacts provide remote indication

of protection status.

indication of protection status. Models

with Silicon Avalanche Diode Modules

(SAD) with extremely low clamping and

exceptionally fast response times are

particularly suited to mobile telecom

applications.

DSP1 and DSP3

Spur Protector



13/15

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15

TRANSFORMER BACKUPGENERATOR

11KV POWER(3-PHASE)

UNDERGROUNDCONDUITS

P.A.B.X. AND OTHERCOMMUNICATIONS

EQUIPMENT

SURGES ARE GENERATED INSIDEBUILDINGS BYAIR CONDITIONERS,

LIFTS, PHOTOCOPIERS, DRINKSMACHINES, FACTORY MACHINERY,

REFRIGERATORS ETC.

SURGES ARE GENERATEDOUTSIDE BUILDINGS BYLIGHTNING,

POWER FAULTS, SWITCHING ANDCONTACT BETWEEN POWER AND

COMMUNICATIONS LINES, ETC.

WALLCONDUIT FOR MAINSAND DATALINE CABLING

415V POWER(3-PHASE)

Supply

Distribution

Surge

Protector

Sub-distribution

Panel Protector

DIN-rail mountab

dataline sur

protecti

Telecom surge

protection

Surge

Protected

Socket Strips

Service Entry

Surge Protector

41

2

9

1

9

8

7

6

6

4

7

12

Spur and InlineSurge Protector

9

67

8


14/15

Telecommunications and Wireless Protection Systems

14

Aircraftwarning light

Microwave dish

TV antenna

Transmissionequipment Digital switching

equipment

Mains powersupply

Typical steelcabin/equipment

room

Induced surgeinto buriedtelecom cable

Common earthbar connected to

all electronicequipment andbonded to theearth ring

DC power equipment(batteries, rectifiers,inverters, converters)

FM broadcast ormobile telephone

antenna

Tower footingring earth

Equipotentialearth bonding

3

4

1

2

1MDSP AC powerprotection 4

Co-axial surge protector

barriers

FEATURES:

Exceptionally high surge handling Two stage (redundant) protection Replaceable DIN rail mount modules Dual thermal/current overload fusing Status indicators with remote signalling Silicon Avalanche Diode models

available for extremely low clampingand exceptionally fast response time

Site wiring fault indicator

APPLICATIONS: Front end of building protection for

mission critical sites and applications SAD models particularly suited to

mobile telecom applications.

FEATURES:

Din rail or panel mounting Low let-through voltages

Fast response times High surge handling capability

Negligible effect on normal lineoperation

APPLICATIONS:

LANs EPOS

CCTV Ethernet Plant & Process Control

Signalling and telemetry

Modular Distribution

Surge Protector

3

Telecommunications lineprotector installed inMDF to protect sensitivetelecoms equipment

FEATURES:

Surges reduced to below normal signalvoltage

High surge handling capability

Negligible effect on normal lineoperation

Models available for connection toLSA-Plus termination strips

Optimum performance with lightningrelated surges

APPLICATIONS: PABX PSTN

Telephone and facsimile Computer communications using

voice line modems

Telecom Line

Protectors

2Surge protector installedon AC power supply toaircraft warning light

FEATURES:

High surge handling capability Two stage (redundant) protection Full protection status indicators

Remote signalling version available Fast response time and low let-

through voltage

APPLICATIONS:

Front end of building protection

Sub distribution panel protection

Individual protection of critical &costly equipment such as computer

systems

Distribution Surge

Protectors

Network & Signal Line

Barrier Protectors



15/15

I dont need surge protection because my

building already has structural protection.

WRONG!

Structural lightning protection and lightningconductors do not protect the sensitive

equipment within the building.

I dont need surge protection because my

system is connected to a UPS.

WRONG!

Most UPSs are not designed with BS6651 in mindand consequently any surge protection fitted is

likely to be limited in its surge handling capability.

Any protection fitted inside the UPS is specificallydesigned to protect its own electronics, not the

equipment connected to it.

UPS bypass switches, when in operation, reduceany protection afforded by the UPS.

Lightning never strikes twice.

WRONG!A site that has been struck once is clearly

susceptible and will often suffer problems on a

regular basis.

My site is surrounded by tall buildings,

so is safe from lightning damage.

WRONG!

Tall buildings may attract lightning away fromyour site, but, your systems will be at risk from

the secondary effects caused by the

electromagnetic pulse generated when lightning

strikes nearby.

Your site is also at risk from surges andtransients present on incoming power andcommunication cabling.

The cabling between my two buildings is

underground, so doesnt need protection.

WRONG!

When lightning strikes the ground, even 1 or 2km away, the current discharged raises the

ground potential in the surrounding area by

100,000s of volts depending on proximity to the

strike. While the current dissipates through theground, a difference between the building earth

points stresses the cable and any connected

equipment.

QI didnt hear anything aboutsurges and transients tenyears ago. Why are they causing

problems NOW?

ATodays computers use smaller and

more sophisticated electronic

components than ever before which are far

more sensitive to transient voltages than

earlier technologies.

Furthermore, we can now put computers

and communication equipment anywhere

we want so must be aware of variations in

the quality of different operating

environments. Perhaps more importantly,

the electricity supply companies are not

required to provide computer-grade power,

so it is our responsibility to ensure thepower used for our computers is clean.

QWe get very little lightning inmy area. Do we still needtransient suppression equipment?

ALightning is only one source of

transients. Repetitive, low level

spikes on power and communication lines

cause circuit degradation and eventual

example, different types of computer network

use a variety of connector formats, signal

levels and operating frequencies. Some

applications are contained within one

building, however, others include data and

power connections between several buildings

which have different protection needs.

QHow do surge protectorswork?A

Surge protectors continuously

monitor the power or signal line for

overvoltages. When the voltage rises

above a certain level components inside

the protector divert the excess energy to

earth and limit the voltage to a safe level.

QWhat is thermal overloadprotection and why do I

need it?

ABowthorpe products have thermal

overload protection fitted as

standard. Surge protection products where

protection elements are not fitted with this

safety feature can overheat under fault

conditions and give rise to the risk of

electric shock or fire.

failure. These spikes are frequently caused

by utility power switching and heavy

industrial power users.

QIs it possible for transients to

affect my equipmentunnoticed?

AAbsolutely. Small transients can be

an invisible problem, they dont

necessarily cause immediate equipment

failure, but WILL cause micro bullet holes

inside semi-conductor electronics leading to

degradation.

After some period of time, the hardware will

fail and be replaced under the assumption

that it died a natural death of age.

However, its life expectancy is actually

shortened by the degrading process. In

other words, the useful life of computer

equipment can be extended by installing

surge protection.

QIs there one completesolution that provides totalprotection?

AEvery system and application is

different in one way or another. For

Questions and Answers

Common Misconceptions

application guide for surges

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