lightening effects and protection.pps

7/28/2019 lightening effects and protection.pps

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9,2, Vanchiadithan New Street, Vadasery, Nagercoil 629001. Ph. 04652 277079 / 275197. fax. 04652 274352

Welcome to the expert seminar on

"Surge protection in electrical energy technique

Presented by: S. Gopakumar, Director, Cape Electric Corporation


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7. Applications

2. How lightning discharges arise

1. Introduction

3. The causes and effects of surge voltages

4. Protection against lightning discharges

6. Type of arresters and selection

5. International Standards

8. Summary / Question and Answers!

Seminar contents and sequences


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1.0 Introduction

Lightning protection systems

External lightning

protection

Air Termination

Down Conductor

Earth Termination

Room shielding

Internal lightning

protection Surge protection

The measures taken toensure surge protection,are separate from theinstallation of a lightningprotection system.

However, they must becoordinated with theinternal lightning protection.

Lightning equipotential

bonding

Room shielding

Safety Distance

Internal lightning

protection Surge protection

The measures taken toensure surge protection,are separate from theinstallation of a lightningprotection system.

However, they must becoordinated with theinternal lightning protection.

Lightning equipotential

bonding


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Chapter 2

How lightning discharges arise


5/1089,2, Vanchiadithan New Street, Vadasery, Nagercoil 629001. Ph. 04652 277079 / 275197. fax. 04652 274352

2.2.1 How is a Lightning Current Waveform

-40

-20

0

0 200 400 600 800 1000

s

kA

100 300 500 700 900

Period between the discharges,up to a few milliseconds

Note: The energy effects of all lightning discharges within an ionisation channel are simulated

by the test waveform 10/350 s in IEC 61024-1, Protection of structures against lightning

and IEC 61312-1, Protection against lightning electromagnetic impulse (LEMP).

Main discharge

Secondary dischargei



2.2.2 Frequency of lightning strikes

0

5

10

15

20

25

0-10

10-2

0

20-3

0

30-4

0

40-5

0

50-6

0

60-7

0

70-8

0

80-9

0

90-10

0

100-110

110-120

120-13

0

130-140

140-150

150-160

160-170

170-180

180-190

190-200

Lightning amplitude [kA], positive and negative lightning strikes

Lightningfrequency,%


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Chapter 3

The causes and effects of surge voltages



3.1.1 A direct strike on a building without anexternal lightning protection installation



3.1.2 Effects (direct strike)

A direct strike on a building without

external lightning protection system

If an electric current flows as a consequence ofa lightning strike to a building, energy isconverted, heating the part of the buildingthrough which the current is conducted to earth.

In addition, material may be melted or ejectedat the foot of the strike.

0

2dtiRW

Effects: fire hazardDue to: specific energy,charge

0

idtQ



3.2.1 Direct strike on an overhead high-voltage line



3.2.2 Effects

Direct strike on an overhead

high-voltage line

For a lightning strike on an overhead line, theimpedance at the first moment is determinedby the surge impedance of the line.

This impedance (ZW) is usually in the regionof 400 to 500 ohms for a single conductor.

2Z IU W

Effects: Overvoltages (voltage surges)

Due to: Maximum lightning impulse current



3.3.1 Direct strike on a low-voltage overhead line


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3.3.2 Effects

Direct strike on a low-voltage

overhead line

The preconditions of a direct strike on a low-voltage overhead line are not the same as fordirect strikes on high-voltage overhead lines.

The fundamental difference is in the proximityto the building through which the conduction

of partial lightning currents is possible.

Effects: Overvoltages (surges) in the low-voltage network, partial lightning current

due to: Maximum lightning impulse current

Source: Kopecky/Aachen


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3.4.1 A direct strike on a building with an externallightning protection installation


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L1L2L3

PEN

3.4.2 Effects

A direct strike on a building with an

external lightning protectionbut without equipotential bonding

If the lightning current from a lightning strike isdiverted to earth, there will be a voltage rise atthe earthing point of the installation. This will becarried into the house via the equipotentialbonding system.The equipotential bonding for lightning protection(lightning arresters / class B) prevents damage tothe electrical installations.

earthoninstallatiRiU

Effects: Overvoltages, insulation breakdownDue to: Maximum lightning impulse current


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3.5.1 Lightning strike to a tree (close strike)


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3.5.2 Effects

Lightning strike to a tree (close strike)

If current flows as a result of a lightning strike to atree, energy is converted (fire hazard).

In addition, the current diverted to earth can becoupled into the earth lines or the nearby building.

Also the electromagnetic field could destroyelectronic equipments inside the building.

Effects: Coupling of the lightning current into earthlines, inductive and galvanic coupling,fire hazard.


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3.6.1 Inductive coupling


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3.7.1 Switching actions


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3.7.2 Effects

Switching actions

Switching actions occur almost everywherewhere work is done with electrical energy.

Especially are areas in which large inductiveloads are switched, for example:

MotorsTransformersChokes

Welding equipmentLong runs of fluorescent tubes

Effects: Overvoltages (surges) on network linesDue to: Energy being returned to the network

Source: Kopecky/Aachen


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3.8 Transient overvoltages

Voltage- disturbances in low-voltage networks

30

26

22

18

10

6

2

14

Overvoltage factor / K

1500(I)

2500II

4000(III)

6000(IV)

rv

Lightning surges

Switching surges

Temporary voltage rises

Harmonics and

slow and fast voltage fluctuations

Voltage breakdown

Short interruptions


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3.9 History of EMC

1950 1960 1970 1980 1990

Disturbance variables

Time

Immunity to interferenc

Now

Vacuum tubes

Transistors

Integrated circuits


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4.3 IEC 60364-4-443 Insulation coordination

6000 V4000 V

2500 V1500 V

IV III II I

Lift

Staircase lighting

Apartments

400 V 230/400 V 230 V 230 V

Surge withstand voltage of insulation

Installation category


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4.2 Lightning protection zone concept accordingIEC 61312-1

B Lightning arrestersto VDE 0675 Part 6 (A1, A2)Requirement class B (


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4.1 Equipotential bonding for lightning protectionaccording IEC 61024-1 and IEC 61312-1

The 100% of lightning energy breaks downas follows:

a) 50% of the lightning current will flow through

the ground

b) 50% of the lightning current will flow over the

connected metal parts out of the building:

about 10% to the water pipe (metal)

about 10% to the gas pipe (metal)

about 10% to the oil pipe (metal tank)

about 10% to the sewage pipe

about 10% to the power suppliers incoming feed

max. 5% or 5 kA shared across all data lines

50 %

50 %


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Chapter 5

International Standards

5 1 N ti l d i t ti l t d d


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5.1 National and international standards(lightning protection)

IEC 61024-1

External lightning

protectionInternal lightning

protection

Lightning protection System (LPS)

Air

TerminationDown

ConductorEarth

TerminationRoom

ShieldingSafety

DistancesLightning

Equipotential

Bonding


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5.2 Different Standards for lightning protection

Protection of structures against lightning

European StandardCENELEC

ENV 61024-1

International StandardIEC

IEC 61024-1 General Principles IS

IEC 61024-1-1 Guide A: Selection of

IS protection levels for LPS

IEC 61024-1-2 Guide B: Design,IS installation, maintenance

and inspection of LPS

IEC 61663-1 Fibre optic installations IS

IEC 61663-2 Lines using metallic conductors IS

Lightning protection - Telecommunication lines


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5.3 Different Standards for LEMP

Protection against lightning

electromagnetic impulse (LEMP)

European StandardCENELEC

prEN 61312-1

International StandardIEC

IEC 61312-1 General Principles IS

IEC 61312-2 Shielding, bonding and

TS earthing inside structures

IEC 61312-3 Requirements of surge

TS protective devicesIEC 61312-4 Protection of equipment

TR in existing structures


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Chapter 6

Types of arrester and typical applications


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6.1.1 Spark gap technology

Metallic Conductors

Air Gap

The operating voltage can be determined by the distances between the electrodes.Spark gaps are arresters in which two or more electrodes in series are opposed to each other. Theelectrodes consist of incombustible material ( metal, carbon, etc).If a spark gap fires, the operating voltage collapses to the anode-cathode drop voltage.


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Conducting

Materiel

Air Gap


Blow out / Exhausting Hole


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During a Lightning

current admission, thespark gap blows hot

ionized gases through

the holes provided in the

arrester. Ionized gases

are good conductors of

electricity. Hence Blowout type arresters

should be connected

away from live parts.

These devices should be

installed in pressure

releasing typeenclosures

6 1 1 S k h l E l d


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6.1.1 Spark gap technology Encapsulated

Output impulse

4

2

1 S

U(kV)

t/(s)Input impulse

(kV)

1

0,5

1 S

U

t/(s)

ElectrodesSpacers made frominsulating material

High Follow Current extinguishing capacity is achieved by connecting Spark Gaps in series,

There by splitting the arc.

6 1 2 V i t t h l


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6.1.2 Varistor technology

Intermediate phase

ElectrodesEpoxy resin

sintered zinc oxide grains withadditives of other metallic oxides

Zinc oxideMicro-varistor

= 10 m

tinned copper wire

1) Source: Siemens DruckschriftMetalloxid-Varistor SIOV

t/(ns)Output impulse

U(V)

Input impulse

U

t/(ns)

(V)

Varistors are voltage-dependent resistors with a highly non-linear U/I characteristic.

The electrical properties arise from a large number of micro-varistors connected in paralleland in series.The transitions between the micro-varistors age under the influence of overvoltages.

6 1 3 Di d t h l


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6.1.3 Diode technology

Input impulse

U

t/(ps)

(V)

Output impulse

U

t/(ps)

(V)

Voltage(V)

Current

(A)UC UB UR

UCUBUR

Transzorb diodes (also known as suppresser diodes) are diodes that limit both positive

and negative voltage.They switch in the picosecond region and are especially well suited for use in data lineprotection devices.

6 1 4 Arrester technologies


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6.1.4 Arrester technologies

How to limit big lightning currents

and surge overvoltages!

Spark gaps

High-performancespark gaps have avery high dischargecapacity, which is whythey are used aslightning arresters.

Varistors

Varistors are used insurge arrestersand fineprotection devices.Unlike other types ofarrester, their ability tocarry lightning current

is limited.

Diodes

Transzorb diodes, alsoknown as suppresserdiodes, are used as diodearresters only in fineprotection devices.They are characterised by

a fast response, but theirdischarge capacity islimited.

6 2 1 Arrester Standardisation


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6.2.1 Arrester Standardisation

IEC 61643-1/ (VDE 0675, P.6/A1/A2)Surge Protective Devices Connected to Low-Voltage Power Systems:

Performance requirements and testing methods

IEC 61643-12Surge Protective Devices Connected to Low-Voltage Power Systems:

Selection and application principles

IEC 61643-21Surge Protective Devices Connected to telecommunication and signalling networks.

Performance requirements and testing methods

IEC 61643-22Surge Protective Devices Connected to telecommunication and Signalling Networks

Selection and application principles

6 2 2 Arrester Standardisation


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6.2.2 Arrester Standardisation

IEC 61643-1:1998 / VDE 0675, P.6/A1/A2Surge Protective Devices Connected to

Low-Voltage Power Systems

Type 1 / B

Arrester for lightning

equipotential bonding.

Tested: Iimp (10/350)

In (8/20)

Type 2 / C

Arrester for Overvoltage

surge protection.

Tested: Imax (8/20)

In (8/20)

Type 3 / D

Fine protectors for mobile

use and for the top-hat rail.

Tested: Uoc (1,2/50)

(8/20)

6.3.1 Types of SPDs IEC 61643-12


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Examples of one-port SPDs

aKey

a. One-port SPDs

U

U

Ub b. One-port SPD with separate input and

output terminals

SPDcc. Generic symbol for a one-port SPD



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Figure 2 :- Examples of two-port SPDs

a. Three-terminal two-port SPDa

U

Z

bU

Z

Z b. Four-terminal two-port SPD

c SPD

c. Generic symbol for a two-port SPD

ZSeries impedance between input andoutput terminals

6.4.3 Types of SPDs IEC 61643-12I


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Response of one-port and two-port

SPDs to a combination wave impulse

aa. Applied current

waveform0 t s

Ip

820

b U

0 t

U

b. Response of voltage

limiting type SPD

c

0 t

U

c. Response of voltage

switching type SPD


Figure 3 :- Response of one-port and two-port


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f. Response of two-port

voltage limiting type SPD

with filteringf

0 t

U

U

Z

NOTE : The voltage levels are only representative and not an indication of actual values.

g p p p

SPDs to a combination wave impulse

d

0 t

U

U

d. Response of one-portcombination type SPD

e

0 t

U

U

Z

e. Response of two-port

combination type SPD

6.5 Types of SPDs IEC 61643-12


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Single voltage limiting component: Limiting type SPD

Single voltage switching component: Switching type SPD

U

Combination of voltage limiting and switching components:

Combination type SPD

6.6.1 IEC 61643 12: Coordination Rules and Principals


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1. Between two ZnO Varistor based SPDs: Possible only for one port

limiting type SPDs

2. Between a gap based arrester (One port switching type) and a ZnO

Varistor based arresters (One port limiting type).

Coordination between Gap based arrester with voltage protection level of < 4KV and aresponce time of 200 ns with a ZnO based arrester with a Nominal Discharge Current In of5 KA requires approximately 27.2 H inductor or 27.2 meter cable for a perfectcoordination

6.6.2 Coordination.


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Class C arrester starts discharging. Voltage V1 drops at Class C. Corresponding to di/dt

V2 drops at inductor. When V1+V2 = Voltage protection level of Class B arrester, it starts

conducting.

4 KV

I

V

3.2 KV

V 800 V

V

t

4 KV

Class CSingle Port

Voltage Clamping TypeRated for 8/20 s

Class BSingle Port

Voltage Switching TypeRated for 10/350 s

V1

V2

6.6.3 Response of Class B , C and Inductor for a low voltage High Energy Surge.


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Class C arrester starts discharging and will clamp the voltage to V1. Inductor starts clamping the

voltage. Since di/dt is very low, voltage V1 comes to minimum after the initial rise. Complete energypasses through Class C.

I f Class B arrester has a low v ol tage protect ion level , i t has more con trol on th is kind o f surge.

4 KV

6.6.4 Class B & Class C arresters without proper coordination


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Class B arrester never operates since Class C arrester clamps the voltage at less than 2 KV at 40

KA. The entire current flows through Class C arrester resulting in the failure of Class C

4 KV

Low Inductor / Low Distance

V 1.75 KV at40 KA

6.7 Follow Current


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Once Class B arrester is switched on, it shorts the Line and Neutral (or Line and Earth). After the surge current,

short circuit current of the network starts flowing through the arrester. Finally the backup fuse F1 or F2 interruptsthe short circuit current. Short Circuit current following the surge current is called as follow current. Class B

arrester should be capable of extinguishing this follow current without the help of fuse F1 or F2.

Class CSingle Port

Voltage Clamping Type

Rated for 8/20 s

Class BSingle Port

Voltage Switching Type

Rated for 10/350 s

4 KV

F1

F2

Sub StationTransformer

6.8.1 Selection Of Class B arresters for Power Line Protection


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1. Enclosure

Exhausting / Encapsulated

Special Fireproof / Explosion

proof Enclosure required

Special enclosures with spring

loaded doors are generally used.

The purpose of spring loaded doors

is to open automatically in case of

high pressure inside the enclosure

due to a Blowout

No Special requirements

Can be mounted in

ordinary Metallic/ PP

enclosures


2. Coordination2. Coordination: If Coordination Distance/Inductance Value is not properly maintained


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Voltage Protection Level of Class B

arresters

Minimum Coordination Distance / Inductance

Value required

Line to Neutral 4 KVNeutral to Earth 4 KV

15 meter cable or 15 H Inductor

Line to Neutral 2 KVNeutral to Earth 2.5 KV


Line to Neutral 1.5 KVNeutral to Earth 1.5 KV

Coordination not required

Line to Neutral 1.5 KVNeutral to Earth 4 KV


Line to Neutral 4 KVNeutral to Earth 1.5 KV


2. Coordination2. Coordination: If Coordination Distance/Inductance Value is not properly maintained

Class B arrester will not operate resulting the failure of Class C arrester.



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3. Follow Current.

What happened on a spark gap during a surge current?

The spark gap will make an equipotential bonding between line and earth, or line and neutral.

That depends where the gap has been installed. So the spark gap will make a short circuit during the

surge.What happened during a shortcircuit?

During the whole time, the nominal voltage of 230V is still on our spark gap. So this nominal

voltage pushes now a short circuit current over your shorted spark gap arrester.

What happened after the surge?If the surge current is over, the spark gap is still in the same condition, that it is like a shortcircuit and the short circuit current from the main line is still going over the spark gap. Now the spark

gap must be able, to cut off this short circuit current by itself, before the fuse will cut off the current.

Follow Current

The short circuit current following the surge current is called as Follow Current. Follow current is equal to

the peak short circuit capacity of the network. The class B arrester should eliminate (cut off) this shortcircuit current without the help of Back up Fuse. Short circuit value can be calculated based on the

transformer capacity and the distance between the transformer and installation. Approximately 10 to 15KA

will be ideal for telecom installations. Otherwise this will blow the fuses in case of a Lightning

4 Follow current: Fuse Selection of Class B Arrester



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4. Follow current: Fuse Selection of Class B Arrester

Short Circuit at installation Point

in KA

Fuse selection of Class B Arrester with

Short Circuit extinguishing capacity of

4KA

5,6,10 &25 Higher values of short circuit current

will cause the backup fuse to blow.

Use of backup fuse higher than 125 Amps will cause the surgearrester to fail due to excessive follow through current

1.5 50

2 63

2.5 80

3 1003.5 100

4 125

1 35

6.9.1 Type of arrester / Lightning arrester class B


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Requirement class : B according VDE 0675, part 6Requirement class : Type 1 according IEC 61643-1

Principle of operation : Spark gap / Exhausting(Blow out type)

Impulse current Iimp : 60 kA(10/350) per pole for LA60-B100 KA (10/350) for LA100-B

Protection level Up : < 4 kVResponse time : < 100 ns

Series fuse : separate backup fuse required

Lightning Arrester LA60-B and LA 100-B

Application: Where there is an external lightning protectioninstallation, overhead line feed and high networkavailability.



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Principle of operation : Spark gap / Multi-Carbon-Technology(encapsulated)

Impulse current Iimp : 50 kA(10/350) per pole Discharge current Imax : 120 kA(8/20) per pole

Protection level Up : < 2 kV Response time : < 100 ns Series fuse : no separate series fuse in

installations up to 500 A Mark of conformity : VDE, VE, KEMA, EZU, MEEI

LightningController MC 50-B VDE

Application: Where there is an external lightning protection installation, overhead

line feed and high network availability.In industrial plants and for high lightning protection classes.



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Principle of operation : Spark gap / Multi-Carbon-Technology(encapsulated)

Impulse current Iimp : 125 kA(10/350) per pole Discharge current Imax : 200 kA(8/20) per pole Protection level Up : < 2,5 kV Responce time : < 100 ns Mark of conformity : VDE, VE, KEMA, EZU, MEEI

LightningController MC 125-B/NPE

Application: Where there is an external lightning protection installation, overhead

line feed and high network availability.Lightning arrester for the installation between N and PE.

6.9.4 Application advantage / Encapsulated ArresterLightningController MC


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g g

Advantage for the installer by using

the OBO LightningControllerMC 50-B VDE and MC 125-B/NPE

No special housing necessary!

No minimum distances through

other electrical installations!

6..9.5 LightningController MC


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LightningController MC

MC 50-B VDE

MC 125-B/NPE

Tested according:

E DIN VDE 0675

Teil 6 + A1 + A2

IEC 61643-1 +37 A/95/CDV

6.9.5 Coordinated LightningController MCD


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Improvement of the

protection level to < 1,3 kV

Advantage for the builder of the control cabinet: No need of LightningCoordinator LC 63

2,5 kV

2,0 kV

Direct parallel connection betweenLightningController MCD // SurgeController V20-C is possible!

Important for mobile transmitter stations and industrial distribution!

6.9.6 LightningController MCD // SurgeController V20-C


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Direct parallel connection betweenLightningController MCD // SurgeController V20-C

No decoupling element and no C25-B+C/NPE

is necessary!

6.9.7 Class B & Class C together Grid Surge

Applicable only for Class B

arrester with a response time

less than 100 nano sec


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MCD50-B arresters switches at a low voltage of 700 volt if the energy content is more.Initially Class C arrester starts discharging when the voltage V1 continues for more time,

Class B arrester switches at a low voltage thereby reduces the stress on Class C arrester.

1.3 KV

700 V 1.3 KV

No Inductor / Distance

1.3 KV at InMCD 50-B

V20-C

less than 100 nano sec

6.9.8 Type of arrester / Lightning + surge arresterclass B + C


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Requirement class : B + C according VDE 0675Requirement class : Type 1 + 2 according IEC

Principle of operation : Varistor technology Impulse current Iimp : 25 kA(10/350) per 4-pole block Discharge current Imax : 200 kA(8/20) per 4-pole block

Protection level Up : < 2 kV Series fuse : no separate series fuse in

installations below 160 A Mark of conformity : EZU, MEEI, VdS- approved

Application: Where there is an external lightning protection installation, overheadline feed and high network availability.VdS-approved.

CombiController V25-B+C

6.9.9 Type of arrester / Surge arrester class C


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Requirement class : C according VDE 0675, part 6Requirement class : Type 2 according IEC 61643-1

Principle of operation : Varistor technology Discharge current Imax : 40 kA(8/20) per pole Nom. discharge current In : 20 kA(8/20) per pole

Protection level Up : < 1,3 kV Series fuse : no separate series fuse in

installations below 125 A Mark of conformity : VE, UL, KEMA, EZU, MEEI

SurgeController V20-C

Application: Surge arrester for the installing in the main- and sub- distribution

boards.

6.9.10 Further surge products / Main lines


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Audible signallingdevice AS forV 25-B+C and V20-C

Remote signallingdevice FS forV 25-B+C and V20-C

Fine protectiondevice KNS-D

Fine protectiondeviceVF 230-AC-FS

Checking systemISOLAB

Decoupling element LC 63


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7. Application

7.1 Procedure for selecting surge arresters


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Buildinglightning protection installation?

overhead line?

lightning current coupling possible?

Lightning arresters(Requirement class B)

Installation as close as possible tothe entrance of the building

Surge protection(Requirement class C)

Installation in sub-distribution board

Surge protection

(Requirement class D)Installation as close as possible tothe device to be protected

yes

Surge protection

(Requirement class D)Installation as close as possible to thedevice to be protected

Surge protection(Requirement class C)

Installation In sub-distribution board

Coordinationbetween B and Carresters for line

lengths below 5metres

Coordinationbetween C and D

arresters

no

Class 1(B) and Class 2(C) protectionfor Lightning & Surge Voltage Protection Equipment in TT System

RRF1

(As per IEC 61024-1, IEC 61312-1, VDE V0100-534)

ENT


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SPD1

SPD3

SPD2

SPD4

R

Y

B

N

R

Y

B

N

PE

ACCOMMERC

IALMAINS

ACDISTRIBUTIONPANEL

INPOWER

ROOM

EARTH

F2

F3

SPD5

SPD7

SPD6

SPD8

F4 F5 F6

(Class 1 / B) (Class 2/ C)

Note : The above system is forthree phase configuration. For

single phase one phase

conductor and one neutral

wire shall be used

PE -: Protective Earth

F1, F2, F3, F4, F5, F6 -: Fuses of Proper Rating

SPD1, SPD2, SPD3 -: Surge Protection Devices of rating Iimp 50KA, 10/350s

SPD4 -: Surge Protection Devices of rating Iimp 100KA, 10/350sSPD5, SPD6, SPD7 -: Surge Protection Devices of rating Iin 10KA, 8/20s

SPD8 -: Surge Protection Devices of rating Iin 20KA, 8/20s

LV / HV -: Low / High Voltage Disconnector

Iimp -: Value of Lightning Impulse Current 10/350s

Iin -: Value of Nominal Discharge Current 8/20s

-: Co-ordination cable element

TOEQUIPME

7.1.1 Installation example


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-- Building without external lightning protection --

1. Overvoltage arrester class C

2. Overvoltage arrester class Cin the sub- distribution board

3. Overvoltage arrester class Cfor photovoltaic- facilities

4. Overvoltage arrester class D



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-- Building with external ligtning protection --

1. Lightning Arrester class Bor the CombiController





71/108


-- Office building with external lightning protection --

1. Lightning arrester class B



2. Lightning arrester class Bor CombiController



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-- Industrial building with external lightning protection --

1. Lightning arrester class Bor CombiController



ENT

R1

Class 1 and Class 2 arresters in enclosure with standard inductor. Suitable for small and medium exchanges in TTnetwork


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AC

COMMERCIAL

M

AINS

TO

EQUIPM

Body earthing of all electronic equipments in the

exchange.

Direct earth connection from the body of equipment

to outside earth pit is not permitted.

EBB

To earth pit

Y

B

N

PE

2

3

456

7 8 9

10

11 12 13

14

PE -: Protective Earth

1,2,3,4,5,6 -: Fuses of Proper Rating

7,8,9 -: Surge Protection Devices of rating Iimp >50KA, 10/350s10 -: Surge Protection Devices of rating Iimp > 100KA, 10/350s

11,12,13 -: Surge Protection Devices of rating In > 10KA, 8/20s

14 -: Surge Protection Devices of rating In > 20KA, 8/20s

Iimp -: Value of Lightning Impulse Current 10/350s

In -: Value of Nominal Discharge Current 8/20s

EBB -: Equipotential bonding bar

: Inductor (made by the SPD manufacturer

Earthing


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Incomingpanel

Surgearresters

Powerplant

Exchange

Battery

+_

Other RFdevices

TelephoneLines

PE

PE

Earthing Schematic for exchanges

Earthing


75/108


Incomingpanel

Surgearresters

Powerplant

Exchange

Battery

+_

Other RFdevices

TelephoneLines

PE

PE

Earthing Schematic for exchanges: Wrong connection

Earthing


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Incomingpanel

Surgearresters

Powerplant

Exchange

Battery

+_

Other RFdevices

TelephoneLines

PE

P

E

Earthing Schematic for exchanges: Bonding of different earthings

PE

B1

B1-Special bonding device to bond different earthnigs, 100KA with voltage protection level 1300 V

Railways Application : Token less Block Instrument


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Used for signaling / train movement

between station. Stations are interconnected either byoverhead line or by UG cable.

20 to 35 volt signals are transmittedfrom the stations depending upon thedistance between stations.

12 volt signal is received at thestations.

Transmission and reception is donethrough the same lines. The same lineis also used for voice conversation.



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The input wires are connected to the blockinstrument via spark gaps.

These wires are connected parallely to thecoil of pick up relays, contact oftransmission relays and telephone device.

During lightning season, over voltagechances are high in places where overheadline are used.

If the over voltage occurs when the signal

lines are transmitting, chances of fusefailures are more due to the follow currentcreated by the spark gap during adischarge.

Even though spark gaps are installed in theline, failures are occuring in the blockinstrument may be because of the high

voltage protection level.



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These arrester were burnt during the lightningas well as it was not capable of protecting theinstrument. (A number of pieces burnt. Mightbe all the devices installed)

The failure of the arrester may be due to highdischarge current (more than 20 KA) enteringthrough the overhead lines.

Surge arresters with a discharge capacity of

20 KA were installed in Castle rock railwaystation which has a high lightning prone place.

Arrester with a high discharge current handling

capacity is required for this application


A two stage protection is recommended for thistype of devices


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Stage 2

type of devices. MOV based arrester with a maximum

discharge current handling capacity of 40

KA per pole with in built thermaldisconnector and dynamic disconnector isrecommended on stage1 as per thedrawing.

Class D type arrester designed for 12V DCshould be used in the line connected to thecoil of pickup relay.

Class D type arrester designed for 48V DCshould be used in the line connected to thecontact of transmission relay.

We recommend to install these devices in 2stations most proven for lightning for at least 6months.

Stage 1



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Stage 1

Stage 2

Line 1Line 2

In stage 1 protection, 2 devices are connectedto each line. Hence the total discharge capacityis 80 KA.

Stage 1 protection is required only in placeswhere over head lines are used.

For places where UG cables are used, only

stage 2 protection is required. If the installation is in places where lightning'sare very less, only one Class D type arrester 48V DC can be used for the complete BlockInstrument.

Specification of each devices is as below.

Stage 1 Protection (Only required if over head lines are used)



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Stage 1 Protection: (Only required if over head lines are used)

Class II Type surge arrester single port MOV based with in built Thermal disconnector and

Dynamic disconnector as well as visual indication to determine faulty arresters withfollowing specification.

1. Maximum Discharge current operating voltage DC 100V

2. Nominal discharge current of Single block : 15KA for 8/20s wave form

3. Maximum Discharge current for 8/20s : 40KA

4. Response time < 25ns.5. Test standard : Class II type SPD as per IEC 61643

6. Voltage protection level at 1KA (8/20s ) : 300 V

7. Fixing : Rail mounting type.

8. Connection wires : 2.5 to 6 Sq.mm.

9. Enclosure : Arrester should be installed in polypropylene enclosure with Transparent coverso that inside devices are visible.


Stage 2 Protection : For input to the coil of pickup relay.

Surge arrester based on MOV, spark gap and tranz abzob diode with following rating should bei t ll d t th Bl k i t t ith th f ll i ifi ti


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installed very near to the Block instrument with the following specifications.

Rated current : : 1Amps Nominal Voltage : 12 V Maximum continuous operating voltage : 13.5Volt Nominal discharge current : 10 KA Voltage protection level : 29V

Series Inductance per path : 100H Connection wires : 0.14 to 2.5 mm 2 Fixing : Rail mounting type.

Stage 2 Protection : For output to the contact of transmission relay as well as for the

input and output of telephone .

1. Rated current : : 1Amps2. Nominal Voltage : 48 V3. Maximum continuous operating voltage : 53 Volt

4. Nominal discharge current : 10 KA5. Voltage protection level : 100V6. Series Inductance : 100H7. Connection wires : 0.14 to 2.5 mm 28. Fixing : Rail mounting type.


Coordination between Stage 1 and 2 Protection.

Distance of 3 meters (or 3 H inductor) should be provided between stage 1 and 2 protection.


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Connection diagram as follows.

Stage 2 SPD :

12V DC

Stage 2 SPD :

48V DC

To Output of block

instrument as well as

to telephone

12V input signal to

block instrument

Interconnection

Stage 1

Protection in

enclosure

3 meter cable length is required between Stage 1 and Stage 2

L1

L1

L2

L2

L1 L2


Bonding of Input DC supplies


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Equipotentialisation of Input DC supplies to be done with Class D arresters of suitable

voltages.

Nominal Discharge current In: 10 KA

Bonding

Local Equipotentialisation bonding has to be done by connecting the body of Blockinstrument, earth terminal of all class D arresters (stage 2 protection as well as devices

connected to the DC input to of block instrument.

Earthing

Earthing has to be done as per the drawing.



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PE

DC inputs to Block instrument

Less than 0.5 meter

EBB

PE Local bonding bar

EBB- Equipotential bonding bar of the room

1. Stage 1 protection

2. Stage 2 protection

3. Arresters for the DC input to Block instrument

Earth wire to the building ground

1 2

2

33

SSI: Gidhni site plan (Existing)

Axle Counter

IPS Room

B tt R

TVSS


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SSI

Rack1 Rack2 Relay

panel

TreeTree

EP1 EP2 EP3

EP4 EP5 EP6

EP-Earth pit

Battery Room

1. Body of all devices in the SSI room is connected via

metallic cable trays.

2. Body of SSI and relay panels are connected to thecommon bonding bar with copper cables.

3. Body earthing of axle counter is connected

separately on the backside of the room

4. Common bonding bar is connected to earth pits in

front of the room via copper cables.

5. Body of all devices in IPS room are interconnected

through metallic cable trays.

6. Body of IPS and change over panels are connected to

bonding bar in the room via copper cable.

7. Bonding bar in the IPS room is connected to earth

pits via copper cables.

ASM

ROOMDC

Panel

ACPanel 2

ACPanel 1

SMRPanel C/O

Panel

Axle Counter

Relays

SSI


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Rack1 Rack2 Relay panel

P

C

24 V DC from IPS

12 V DC from IPS

RS485 ports

(To SM Room)

230 V ACRS485 port

PAS or Common Bonding/Earthing Bar

From IPS

Inter

connections

1 . DC and AC Power for SSI as well as PC is

received from IPS

2. Interconnections between SSI main rack and

control panel situated in the nearby building

and routed through metallic pipes.

3 . AC and DC power for control panel and

control PC are routed through metallic pipes.

4. RS485 interconnecting wires are routedthrough metallic pipes connected between

the 2 buildings.

From SM

Room

Gidhni site plan:Possible chances of Coupling of partial Lightning Currents through metallic pipes

connected between two buildings. Power and data cables are routed through these pipes

Axle CounterIPS roomSM

RoomTVSS


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TreeTree

EP1 EP2 EP3

EP4 EP5 EP6

Note: It is clear that there are no lightning and

transient protection devices provided at the SSI

end to protect the inputs (or outputs) against any

surge coming from outside source.

Rack1 Rack2Relay

panel

Battery

Room

PC Control Panel

RS485/232 port PC to SSI

32 pairs of I/O Nonvital

C/O PanelSMR

PanelAC

Panel

AC

Panel

DC

Panel

24V DC

12V DC

230V AC230V AC

Metallic Pipes

connected to

ground

PC

Problem of safety distance.Lightning strike on the wall of the buildings or on the nearby objects can create Inductive coupling of the metallic parts inside the buildings due to thehigh potential created during the current flow.

wall General


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1. Example of problems with

safety distance on a wall

wall

Electronic

installation

R

L

2. Example of problems with

safety distance on a flat roof

R

L

Electronic

installation

TallObjects

General

SSI: Gidhni site planPossible chances of Coupling of partial Lightning Currents due

to spread of radiation if a lighting strikes very close to the building.

Axle CounterIPS room

Battery


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EP1

EP-Earth pit

SSI

Rack1 Rack2 Relay

panel

TreeTree

EP2 EP3

EP4 EP5 EP6

y

Room

Note: Drg. Shown above is schematic for explanation of radiation caused due to lightning and does not include

all the elements (cabinets) of site.

Over Voltage in the ground created a high potential in the body of all devices connected to ground. The devices

which are having the lowest breakdown voltages will damage immediately. If the voltage is so high,

splashovers will happen. Probably the Lightning arrester connected in IPS room must have operated at 2 KV

and diverted the current to the power source. Otherwise there would have been flashes on PCBs.


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Battery

Room

Axle Counter

SSI

Rack1 Rack2 Relay

panel

IPS room

EP2 EP3

TreeTree

EP4 EP5 EP6

Rack1 Rack2 Relay

panel

IPS room

EP2 EP3

Tree

EP4 EP5 EP6

Note: Red colour shows how the radiation

starting ground EP2, EP3 and EP5, moves to throom and affects all equipments connected.

Gidhni site plan-Explanation as what could have happened.

Chance no.1. Ground potential increases due to a discharge either on ground or on the tree (existing outside the building) or any of the nearby objects. Potentialof all the devices connected to earth increases. ( Axle counter body is separately grounded on the backside of building). Chances of failure of all devices due tothe coupling of surge. Failures expected on the non vital I/Os, PCs, SSI main rack PCBs, 12 V & 24 V Power inputs of SSI, IPS inputs and outputs.


RoomTVSS


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EP6

TreeTree

EP1 EP2 EP3

EP4 EP5

Actual following was found at site :

Failure occurred on both PCs, Control panel, SSI main rack PCBs, one output of IPS.

No failure on the IPS Inputs, Lightning and Surge arresters are installed.

No failure on output of IPS, SPDs installed on all outputs.

Recommendations. (Surge arresters should be installed in the following places)

Power supply of PC affected. Recommended device 3. VF 230 AC

24 V and 12 V DC Power supply inputs to SSI. Recommended Device. VF24 DC for 24 Vand VF12 DC for 12 V

RS485 ports affected. Recommended Device 2. SD25 V11 / 25

230 V AC output from IPS No failure occurred. May be due to the presence of SPD

RS 485 ports of Monitoring PC also require protection. Recommended Device 2. SD25V11 / 25

Non Vital inputs Recommended device 1. LSA-BF-24

Rack1 Rack2Relay

panel

Battery

Room

PC Control Panel



C/O PanelSMR

PanelAC

Panel

AC

Panel

DC

Panel

24V DC

12V DC

230V AC230V AC

Metallic Pipes

connected to

ground

PC

Gidhni site plan-Explanation as what could have happened.

Chance No2. Lightning/Radiation in the metalic pipes can create over voltage on all the conductors passing through the metalic pipes. Chances of failure of PCBs

connected to Nonvital inputs in controller as well as SSI, RS485 ports connected to both PC and SSI, Power supply to control PC, 230 Volt Inverter output of IPS.


RoomTVSS


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TreeTree

EP1 EP2 EP3

EP4 EP5 EP6

Non Vital inputs affected. Recommended device 1. LSA-BF-24

RS485 ports affected. Recommended Device 2. SD25V11 / 25

Power supply of PC affected. Recommended device 3. VF 230 AC

230 V AC output from IPS No failure occurred. May be due to the presenceof SPD

RS 485 ports of Monitoring PC also require protection. Recommended

Device 2. SD25V11 / 25

Rack1 Rack2Relay

panel

Battery

Room

PC Control Panel



C/O PanelSMR

PanelAC

Panel

AC

Panel

DC

Panel

24V DC

12V DC

230V AC230V AC

Metallic Pipes

connected to

ground

PC

SSI - Recommendation


RoomTVSS


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TreeTree

EP1 EP2 EP3

EP4 EP5 EP6

Rack1 Rack2Relay

panel

Battery

Room

PC Control Panel



C/O PanelSMR

PanelAC

Panel

AC

Panel

DC

Panel

24V DC

12V DC

230V AC230V AC

Metallic Pipes

connected to

ground

PC

Earthing directly from SSI to

earth pit is not recommended

Earth busbar fro SSI room has to be

connected through the common earth bus

bar in the IPS room.

Arresters to the Dc input of SSI

SUMMARY

Electrical Connections to Microlok and Computers from IPS

1. 24 V DC


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2. 12 V DC

3. 230 V AC (for PC)

Other Inputs and Outputs

1. Vital inputs from relay panel

2. Non Vital inputs from Station control room

3. RS485 ports from PCs

4. RS 485 ports to PCs

5. Separate earthing done for SSI room and IPS room

Probable Chance of Over Voltage

1. Over Voltage on the body of all devices

2. Induced EMF on the cables connected between two buildings through

metalic pipes3. Difference in potential rise of SSI room and IPS room earth may create

flash over.

Recommended SPDs

24V DC - VF24 DC

12V DC - VF12 DC


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230 V ACVF230 AC on the input of PCs

RS485 PortsSD25V11 / 25

All non vital inputs and outputs from the Microlok to the control panel.. LSA-

BF-24

LSA-BF-24 device for Control panel inputs and outputs

One no spark gap between the two earth so that in case of excess voltage rise in

one earth, the effect is neutralized.

I tem no 1 to 4 can be implemented in the f irst phase and i tem no. 5 and 6

can be implemented on the next phase.

7.7 Additional installation guidance

Installations should be based on IEC 60364-5-534 Where lightning arresters are


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The lines to the arrester elements should not be more than 0.5 metres long, so thatno excessive voltage rise can take place in serious cases.

Installations should be based on IEC 60364 5 534. Where lightning arresters areused before the meter, for Germany the TAB (Technische Anschlu Bedingungen)

conditions of the VDEW must be observed.

The earth of the arrester must always be bonded with the earth of the consumerinstallation. If the PE busbar of a distribution board are used, the PE busbar must be

connected to the installation earthing point by a connection which is capable to carrythe lightning current (16 mm to the equipotential bonding bar).

Parallel installation between unprotected conductors (eg to the meter) and protectedconductors (eg supply voltage) must be avoided.

7.8 Connecting wires

If it is not possible to apply the recommended line length ( 0 5m) the surge protection


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If it is not possible to apply the recommended line length ( 0.5m), the surge protectiondevices should not be connected with a spur line, but in a V-shape.

Take care to run the outgoing and return lines as far apart as possible.

Main equipotential

bonding busbar

Bonding busbar

Main equipotential

bonding busbar

0.5 m

0.5 m

7.9 Application example / Wrong Installation


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UL = L * di/dt

UL = 3H * 1kA/s

UL = 3kV

7.10 Application example / Correct Installation


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IN OUT

Loping of Wires

Wiring


102/108


Input and output wires to the arrester

box should be clearly separated.


103/108


Quality of earthing has to be

improved

Chapter 8


104/108


Summary

8.1 Product Guarantee


105/108


OBO- Bettermann gives a 5 years product guarantee of allovervoltage protection devices

8.2 TBS Construct


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OBO CONSTRUCT TBS

Planning software for the construction

of surge protection concepts in TN, TT

and IT network systems in a building.

including: Texts for use in tenders, Technical information on the products

circuit diagrams product overviews calculation of lightning protection class

The program is designed to be clear andeasy to use.

8.3 The concept of overvoltage protection

Energy supply Telecommunications


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All protectors for the different kind of applications you

find in the OBO Bettermann TBS product range!

Energy supply

Measurement and

control lines

Telecommunications

Other data lines

The best lightning and surge protection

will be ineffective unless

every incoming line to the building

is included!

That is the end of our seminar!


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Now we are ready to answeryour questions!

Thank you for your

attention!

Documents

lightening effects and protection.pps