spark_gap

2007 DEHN + SHNE / protected by ISO 16016 EXFS 100 11.12.07 / 5392

2007 DEHN + SHNE / protected by ISO 16016

Ex Isolating Spark Gaps

EXFS 100 (923 100)and

EXFS 100 KU (923 101)

2007 DEHN + SHNE / protected by ISO 16016 EXFS 100

Ex isolating spark gap EXFS 100; Part No. 923 100 Product description / Specifications

14.01.08 / 5240e

Lightning impulse current (10/350 s): 100 kA

Class of lightning currentcarrying capability: H

Nominal discharge current (8/20 s): 100 kA

Rated impulse sparkovervoltage (1.2/50 s): 1250 V

Power frequency sparkovervoltage (50Hz): 500 V

Rated short-duration power frequency withstand voltage (50 Hz): 250 V

Rated discharge current (50 Hz): 500 A / 0.5 s

With M10x25 connection bolt and spring washer on both sides

Gases: II 2G Ex d IIC T6Dusts: II 2D Ex tD A21 IP67 T 80C

Ex isolating spark gap EXFS 100 according to EN 50164-3 for lightning equipotential bonding according to IEC 62305-3,especially for use in hazardous areas on account of explosive gas or dust atmospheres in zone 1 / 2 or 21 / 22.ATEX-certified (94/9/EG)


(17) Special conditions for safe use None

Document:BVS 06 ATEX E 099

EXAM BBG Prf- und Zertifizier GmbH

EC-Type Examination Certificate forEXFS 100 (KU); Part No. 923 100 (923 101)

14.01.08 / 5237


Ex isolating spark gaps

Examples of use


Ex isolating spark gap EXFS 100; Part No. 923 100Application environment

14.01.08 / 5242e

Isolating spark gaps or protective spark gaps are supposed to establish a galvanic isolation of electric parts of the installation, which are not connected with each other under normal operating conditions.

- Specific applications: for establishing a galvanic isolation of insulating

flanges and insulated couplings (e.g. fuel pipes) Cathodic corrosion protection of tanks Cathodic corrosion protection of pipelines Lightning equipotential bonding of gas pressure regulation stations

Assembly:Isolating spark gaps can be mounted between the parts of the installation to be bridged by means of brackets or connectors. When mounting isolating sparks, the shortest possible cable length should be used as long cables increase the danger of inductive voltages putting unnecessary stress on the isolation.


Ex isolating spark gap EXFS 100; Part No. 923 100Application

14.01.08 / 5238e


EXFS 100

Cathodic corrosion protection of tank installations

building earth

+

~

14.01.08 / 5300e


Insulating flange of fuel or product pipelines

insulating flange

insulating flange

gas pressure regulator

14.01.08 / 5303e

EXFS 100

EXFS 100


ground

16 mm Cu

earth-termination system

14.01.08 / 5305e_c

detail

EXFS 100

cathodiccorrosion protection

Installation of EXFS 100

electric actuator, e.g. MOV (motor operated valve)

Insulatingflange


Ex isolating spark gaps EXFS 100 (KU)Application

Reference: Schwelm Anlagentechnik GmbH, Austria

14.01.08 / 5317e_b


5 Steps for selection and correct installation

of Ex isolating Spark Gaps in accordance with

AfK Recommendation No. 5Edition: 2010

andIEC 62561-3:2011 (81/387/CDV)

2007 DEHN + SHNE / protected by ISO 16016 DEHN UK, 2011

DEHN + SHNEGMBH + CO.KG

HANS-DEHN-STR. 1POSTFACH 1640D-92306 NEUMARKTTEL. +49 9181 906 401FAX +49 9181 906 55 401

SALES DEPT. INDUSTRYMARKET MANAGERLIGHTNING AND SURGE PROTECTION

Manfred Kienlein

eMail: [email protected]: http://www.dehn.de


1. StepLightning Protection Level (LPL)

acc. to IEC 62305-1


Risk of lighting strikes and overvoltage for pipelinesCurrent distribution

S1

When lightning strikes a pipeline, the lightning current is evenly distributed in both directions (50:50 rule). This means that the following maximum parameters must be taken into account for the spark gapand its installation environment


AfK recommendation No. 5: Lightning current parameters

In the following the maximum values of the first short stroke for the different lightning protection levels (LPL) (see Table 5 of IEC 62305-1) are used. The lightning protection level is used to implement protection measures according to the relevant set of lightning current parameters.

The parameters for the subsequent negative short stroke are neglected since no significantly high current steepness is to be expected (values based on experience over the last decades) if lightning current is coupled (galvanic coupling) into the pipeline at the place of installation of the spark gap (insulating piece).

Ex isolating spark gaps - Selection procedure in accordance with AfK -


Symbol Unit I II III IV

I kA 200 150

Qshort C 100 75

W/R MJ/ 10 5.6

LPL

s/s 10/350

100

50

2.5

Ref.: Excerpt from IEC 62305-1:2006-1, Table 5

T1/T2

AfK recommendation No. 5: Lightning current parametersCurrent parameters

Peak current

Short stroke charge

Specific energy

Time parameters

First short stroke

Average steepness di/dt kA/s 20 15 10

Ex isolating spark gaps - Selection procedure in accordance with AfK No. 5 and IEC 62305-1


Symbol Unit I II III IV

I kA 100 75

Qshort C 50 37.5

W/R MJ/ 5 2.8

LPL

s/s 10/350

50

25

1.25

Maximum lightning current parameters for connecting cables

T1/T2


Current parameters

Peak current

Short stroke charge

Specific energy

Time parameters

First short stroke

When lightning strikes a pipeline, the lightning current is evenly distributed in both directions (50:50 rule). This means that the following maximum parameters must be taken into account for the spark gap and its installation environment:

Average steepness di/dt kA/s 10 7.5 5

Ex isolating spark gaps - Selection procedure in accordance with AfK No. 5 and IEC 62305-1



Thus, in the following the average steepness of the first short stroke is used for assessing the voltage drop in all connecting cables.

It is certainly possible that lightning directly strikes the insulating piece orthe spark gap. This, however, needs to be prevented by taking adequateexternal lightning protection measures in accordance with IEC 62305-3.

Ex isolating spark gaps - Selection procedure in accordance with AfK -


2. Stepvoltage withstand capability of

insulating jointsacc. AfK No. 5


Two classifications:

Class 1 UPW : 5 kVrms

Class 2 UPW : 2.5 kVrms

AfK recommendation No. 5:

22.12.2010 / 5321e_e

Voltage withstand capability of insulating joints

UPW

Insulating joint


3. Stepconnection cable length

acc. AfK No. 5


Depending on the max. current steepnessof the first short stroke for the relevant class of LPS (LPL) and the connecting cable length, the electric strength of the insulating piece might be exceeded due to the voltage drop across the connecting cable.

This might already occur (based on a class I insulating piece and class of LPS I ) for a cable length of more than 300 mm (for this reason the standard connecting cable lengths are limited to 300mm).

22.12.2010 / 5320e_a_MAK

Max. cable length of connection cables

Note:Connection cable min. 16 mm Cu or equal


(di/dt)max

(di/dt)max

L

R

of the connecting cable

Ref.: Hasse, P.: berspannungsschutz fr Niederspannungsanlagen, TV - Verlag GmbH, Kln, 1998

Ex isolating spark gaps Connecting cable lengths


4. Stepselection of spark gap

acc. AfK No. 5


AfK recommendation No. 5: Selection and installation

Adequate explosion-proof isolating spark gaps should feature the following characteristics:

Tested in accordance with IEC 62561 -3

Lightning current carrying capability: class H or N

d.c. sparkover voltage: > 600 V 1)

100 % lightning impulse sparkover voltage (1.2/50 s): 1.25 kV

1) Normally > at the place of installation

Ex isolating spark gapstechnical data




Rated discharge current (8/20 s): 100 kA

Lightning impulse current Iimp (10/350 s): 100 kA (H), 50 kA (N)

Rated withstand voltage (50 Hz): 250 V 1)

1) Normally > at the place of installation

Ex isolating spark gaps technical data




Rated alternating discharge current (50 Hz): 500 A / 0.5s 2)

IECEx and ATEX certification for the relevant hazardous zone at the place of installation

2) Max. discharge current in case of interference at the place of installation

Ex isolating spark gaps technical data


5. Stepcoordination

spark gap to insulating joints acc. AfK No. 5


Mode of Operation of Ex isolating Spark Gaps


EXTINGUISH

Isolate = Circuit openDuring normal operation the EXFS 100 isolating spark gap has a high resistance (> 500 kOhms). Normal operation of the system is thus not compromised.

Trigger = Circuit closesAs soon as the sparkover voltage Uag or Uas is reached, the EXFS 100 isolating spark gap immediately triggers and reduces the voltage to a safe level.

Discharge = Circuit closedAfter the EXFS 100 isolating spark gap triggered, it discharges the energy content of the interference pulse without posing a risk to the environment.

Extinguish = Circuit opensAfter the energy of the interference pulse has been discharged, the EXFS 100 isolating spark gap extinguishes and changes back to normal operation. The original electrical characteristics are retained and the system is protected again.

DISCHARGE

TRIGGER

ISOLATE

Ex isolating spark gaps Mode of operation


AfK recommendation No. 5: Coordination Ex isolating spark gaps / insulating joints

Coordination between the insulating clearance of the insulating joints and the associated spark gap is to ensure that the discharge process following a lightning discharge is performed via the spark gap and not via the insulating clearance of the insulating joints .

The isolating spark gap thus represents a defined flashover point which prevents discharge with uncontrolled sparking. At the same time, ignition of an explosive atmosphere is prevented.

Coordination during lightning discharge is basically ensured if the voltagecaused by the discharge process does not reach the value of the electric strength across the insulation of the insulating joints .

Ex isolating spark gaps - Selection procedure in compliance with AfK -


Voltage characteristic for insulating joints in case of lightning effects (schematic)

insulating joints


Trigger = Circuit closesAs soon as the sparkover voltage Uag or Uas is reached, the EXFS 100 isolating spark gap immediately triggers and reduces the voltage to a safe level.

TRIGGER

Ex isolating spark gaps Trigger function



The following requirements are to be fulfilled to ensure insulation coordination:

The impulse sparkover voltage Uas (1.2 / 50 s) of the spark gap must be 50 % smaller than the r.m.s. power-frequency test voltage UPW of the insulating joints .Requirement: Uas


Uas 0.5 * UPWClass 1: UPW = 5 kVClass 2: UPW = 2.5 kV

Class 1 insulating joints : Uas 0.5 * 5 kVUas 2.5 kV

Class 2 insulating joints : Uas 0.5 * 2.5 kVUas 1.25 kV

AfK recommendation No. 5:

The impulse sparkover voltage (1.2/50) of the isolating spark gap should be below 50% of the 50 Hz power-frequency flashover voltage (r.m.s. value) of the insulating joints .

22.12.2010 / 5321e_e

Uas

EXFS 100 (KU) Ex isolating spark gaps Trigger function

UPW.



The impulse sparkover voltage (1.2 / 50 s) is determined and specified in a test procedure in accordance with IEC 62561 -3. This ensures that changes of the impulse sparkover voltage as a result of ageing and thus of the coordination requirement are excluded / considered.

Ex isolating spark gaps - Selection procedure in accordance with AfK - Trigger function


Discharge = Circuit closedAfter the EXFS 100 isolating spark gap has triggered, it discharges the energy content of the interference pulse without posing a risk to the environment.

DISCHARGE

Ex isolating spark gapsDischarge function


AfK recommendation No. 5: Coordination Ex isolating spark gaps / insulating piece

The following requirements are to be fulfilled to ensure insulation coordination:

After the spark gap has triggered, the max. voltage drop between the connecting points of the Ex isolating spark gap (Umax) must not exceed the peak value of the power-frequency test voltage ().Requirement: Umax < e.g. class 1 insulating piece: UPW = 5 kV; = 7 kV

Ex isolating spark gaps - Selection procedure according to AfK - Discharge function


AfK recommendation No. 5: Determination of the connecting cable length

Spark gap

Insulation

Ex isolating spark gaps - Selection procedure according to AfK - Discharge function


AfK recommendation No. 5: Formulas for calculating the voltage drop

Ex isolating spark gaps - Selection procedure calculation according to AfK No. 5

insulating piece

(depends on the Ex isolating spark gap)


AfK recommendation No. 5: Sample calculation

Installation height H of the loop: 15 cmConnecting point clearance (cable length) SL: 70 cmTotal length of connecting cables l = SL + 2 * H = 100 cmEx isolating spark gap used: EXFS 100Type of conductor: flexible circular conductor, 25 mm, Cu (rho = 0.0178 Ohms * mm / m); L = 1 H / m Class 1 insulating flange (5 kVrms) = 5 kV x Sqr (2) = 7 kV

insulation

spark gap




Umax = Ubo + Imax * RL + L * di / dtUbo = 30 V (const.)Iimp = 100 kA (wave form 10/350 s) di / dt = 10 kA / sRL = rho * l / A = (0.0178 Ohms * mm / m) * 1 m / 25 mm = 0.712 mOhms L = 1 H / m (typical value)

(depends on the Ex isolating spark gap)

insulating joint




Umax = 30 V + 100 kA * 0.712 mOhms + 1 H * 10 kA / sUmax = 10.10 kVUmax [10.10 kV] > [7 kV]

Coordination requirements not fulfilled !!!

insulation

spark gap



Voltage drop depending on the connecting cablesV

o

l

t

a

g

e

d

r

o

p

[

k

V

]

Connecting cable length [cm]

steepness:

steepness:

steepness:

LPL 1

LPL 2

LPL 3


AfK recommendation No. 5: Measures to be taken if the coordination requirement is not fulfilled

Parallel connection of spark gaps

If the voltage drop Umax exceeds the value of the test voltage UPW specified for the insulating piece (e.g. class 1: 5 kVrms), this can be compensated by installing additional spark gaps.

Ex isolating spark gaps - Selection procedure Measures according to AfK No. 5




Insulation coordination is assured if the number of spark gaps (down conductors N) multiplied with the peak value of the test voltage of the insulating piece () is equal to or greater than the value calculated for the voltage drop across all connecting cables (Umax).

Requirement: >= Umax / N

Note:Type of spark gap and cable length have to be the same





Formula: N = Umax / = 10.10 kV : 7 kV 2N: number of spark gaps

In order to protect the insulating piece, two spark gaps must be installed in parallel (symmetrical arrangement) at the flange.

If several spark gaps are connected in parallel, the spark gaps ignite one after the other and the electric strength of the insulating piece is never exceeded.





Note:It is advisable to perform a type test (verification of coordination between insulating piece and spark gap with connecting cables) for the parallelarrangement of spark gaps with insulating piece in an impulse current laboratory with the relevant lightning current parameters according to the LPL.




Parallel routing of the feed and return cable

Parallel routing of the feed and return cable(might be additionally twisted) e.g. if the spark gap is installed above ground.

Coaxial cable arrangement e.g. if the spark gap is installed above ground (see Figure B.1)

isolating point

reinforcement

concretefoundation

spark gap

coaxial cable:sheath at least 1 x 162

tube at least 1 x 162

e.g. type 1/2Cu 2Y 75 Ohms

e.g. measur-ing pile

DIN rail

terminals




Parallel routing of the feed and return cable

Note:It is advisable to perform a type test (verification of coordination between insulating piece and spark gap with connecting cables) for the parallel arrangement of spark gaps with insulating piece in an impulse current laboratory with the relevant lightning current parameters according to the LPL.

isolating point

reinforcement

concretefoundation

spark gap

coaxial cable:sheath at least 1 x 162

tube at least 1 x 162

e.g. type 1/2Cu 2Y 75 Ohms

e.g. measur-ing pile

DIN rail

terminals



Type Tests for Insulating Joints with Ex isolating Spark Gaps


Test Set-up


Schematic test set-up

Insulating joint

Connecting cable length l (25 mm2)

External EXFS 100 spark gap

Lightning current generator200 kA, 10/350 s


Photo of the test set-up

Earthing

Injection ofimpulse current

Impulse current generator200 kA, 10/350 s

Insulating jointat the pipeline


Photo of the test set-up


Oscillograms of the impulse current testWave form 10 / 350 s

Total current

Oscillogram 1: Test 1 - Connecting cable length of 40 cm

Current flowing through the external EXFS spark gap

Total current

current through EXFS


Oscillograms of the impulse current testWave form 10 / 350 s

Total currentCurrent flowing through the external EXFS spark gap

Oscillogram 2: Test 2 - Connecting cable length of 60 cm

Total current

current through EXFS


EXFS 100 (923 100)and

EXFS 100 KU (923 101)

-

more than just spark gaps

2007 DEHN + SHNE / protected by ISO 16016 EXFS 100 14.01.08 / 5297e_a

EXFS 100 -more than just an isolating spark gap

Lightning impulse current (10/350): 100 kA

Class of lightning current carrying capability: H

Rated short-duration power frequencywithstand voltage (50Hz): 250 V

Rated impulse sparkovervoltage (1.2/50): 1250 V

A.c. sparkover voltage (50 Hz): 300 V

Nominal discharge current (8/20): 100 kA

Rated discharge current (50 Hz): 500 A / 0.5 s

Connection enclosure with M10 x 25 connection bolt and spring washer on both sides

Test acc. to EN 50164-3 - Lightningprotection

Testing of further practice relevent loadings of the spark gap

AfK-recommendation


Pipelines affected by interferences

pipeline

lightning strike

electromagneticinterference

earth fault /short-circuit current

earth electrode earth electrode leakage currents caused by electrical railway systems

14.01.08 / 5422e_a


leakage currents caused by electrical railway systems

galvanic pulse injection via the soil

electromagnetic fields caused by high-voltage transmission lines

inductive pulse injection

earth faults and short circuits caused by high-voltage transmission lines

galvanic / inductive pulse injection

lightning interference caused by thunderstorms

galvanic / inductive pulse injection

Sources of interference can be

14.01.08 / 5422e_b



transientswitch

additionallyswitch for controlling of short-term interferencesof high-voltage systems(up to 500 ms)

14.01.08 / 5297e_b


Non-standard parametersfrom practice



If pipeline systems are in the influence area of high-voltage systems, the spark gap has to carry high alternating currents in case of response. This short-term interference (AfK recommendation No. 3) causes a thermal loading which can damage the spark gap. The max. break-time at earth faults is approx. 0.5 seconds.

By the rated discharge current thus a max. admissible 50 Hz current load is defined, which can be carried by the EXFS 100 (KU) for a certain time.The specified value for the EXFS 100 (KU) is: 500 A @ 0.5 s

Within the test scope it had to be proved that the EXFS 100 (KU) will not be damaged electrically / mechanically, the limit temperature for the temperature class T6 (85 C at 40C ambient

temperature) on the enclosure surface will not be exceeded and after the test the rated values according to EN 50164-3 are kept again.

14.01.08 / 5329e_a


kV

-1.0

-0.5

0.0

0.5

1.0

-1.0

-0.5

0.0

0.5

1.0kA

0.0 0.2 0.4 0.6 0.8 1.0 s

EUT_01: I_follow

EUT_01: U_total

14.01.08 / 5298e_a

0.1 0.3 0.5 0.7 0.9

test voltage: 600 V / 50 Hztest current: 500 Aduration: 0.5 s

a.c. withstand voltage: 250Vimpusle sparkover voltage: 1250Vleakage resistance: 500 k

Before and after the test:

EXFS 100 -50 Hz test


heating 40K

EXFS 100 -50 Hz test

Ex protection safety during the whole duration of interference!

Heating by 40 K

max. surface temperature < 85 C

keeping of T6

Test_01: Temperature C

55

60

65

70

20

35

40

45

50

0 100 200 300 400 500 s

25

30

14.01.08 / 5298e_b


Competitors on the EXFS 100 (KU)

- OBO Bettermann- Leutron- Hakel


Rated impulse sparkover voltage (1.2/50 s): 1250 V 3000 V ( 50%)min: 1500 V / max: 4500 V

A.c. sparkover voltage (50 Hz): 500 V 1000 V ( 50%)min: 500 V / max: 1500 V

D.c. sparkover voltage: > 600 V

Nominal discharge current (8/20 s): 100 kA 100 kA

Lightning impulse current (10/350 s): 100 kA 100 kA

Class of lightning current carryingcapability acc. to EN 50164-3: H H

Rated power frequency withstand voltage (50 Hz): 250 V

Max. d.c. continuous operating voltage: 350 V

Rated discharge current (50 Hz): 500 A / 0.5 sec.

Ex isolating spark gaps - Competitors Comparison DEHN EXFS 100 - OBO PAREX 480

PAREX 480EXFS 100

14.01.08 / 5322e_a


PAREX 480EXFS 100

EC-type examination certification: BVS 06 ATEX E 099 BVS 04 ATEX E 054

Explosion protection - gases: II 2G Ex d IIC T6 II 2G EEx d IIC T6

- dusts: II 2D Ex tD A21 IP67 T 80C not certificated

for dust

Degree of protection: IP 67

Ambient temperature: (-20 ... +40)C (-20 ... +50)C


14.01.08 / 5322e_b


Remarks to OBO / PAREX 480:

No test units available; the data sheet, however, specifies Risol 100 M

no KU types for underground application

with a connecting cable length of 180 mm, 250 mmor 350 mm only at one side


14.01.08 / 5322e_d


EXFS 100

Rated impulse sparkover voltage (1.2/50 s): 1250 V 950 V (typ. 650 V)A.c. sparkover voltage (50 Hz): 500 V 70 V ( 20%)

max: 84 V

D.c. sparkover voltage: > 600 V 100 V ( 20%)



Class of lightning current carrying capability according to EN 50164-3: H N




Ex isolating spark gap - CompetitorsComparison DEHN EXFS 100 - LEUTRON TC 100 A

TC 100 A

14.01.08 / 5323e_a


EC-type examination certification: BVS 06 ATEX E 099 ZELM 02 ATEX 0095X

Explosion protection - gases: II 2G Ex d IIC T6 II 2G EEx m II T3

- dusts: II 2D Ex tD A21 IP67 T 80C

Degree of protection: IP 67 IP 67


Ex isolating spark gaps - CompetitorsComparison DEHN - LEUTRON TC 100 A

EXFS 100 TC 100 A

14.01.08 / 5323e_b


EXFS 100 TC 500 A

Rated impulse sparkover voltage (1.2/50 s): 1250 V 1300 V (typ. 950 V)

A.c. sparkover voltage (50 Hz): 500 V 350 V ( 15%)

D.c. sparkover voltage: < 600 V 500 V ( 15%)



Class of lightning current carrying capability according to EN 50164-3: H N




Ex isolating spark gaps - CompetitorsComparison DEHN EXFS - LEUTRON TC 500 A

14.01.08 / 5323e_c


EXFS 100 TC 500 A

EC-type examination certification: BVS 06 ATEX E 099 ZELM 02 ATEX 0095X

Explosion protection - gases: II 2G Ex d IIC T6 II 2G EEx m II T3




Ex isolating spark gaps - CompetitorsComparison DEHN EXFS - LEUTRON TC 500 A

14.01.08 / 5323e_d


Remarks to LEUTRON TC100 A And TC 500 A:

There are special requirements (X behind certification number); such as EXFS C1 (923 070)

equalising currents enclosure 50 V dc constantly must not be exceeded isolating spark gap to be installed free from mechanical tensions the isolating spark gap has to be installed so that it is protected against direct weather

influences

Ex isolating spark gaps - CompetitorsLEUTRON TC 100 A and TC 500 A

Fail Safe - performance

no test units available; specification in the data sheet Risol 109

KU-type available for underground application

connecting cable set K1/300 with 30 cm cable length available

14.01.08 / 5323e_e


HS 100 ExEXFS 100

Rated impulse sparkover voltage (1.2/50 s): 1250 V < 1500 V

A.c sparkover voltage (50 Hz): 500 V > 500 V

D.c sparkover voltage: > 600 V 400 - 750 V



Class of lightning current carrying capability according to EN 50164-3: H

Rated power frequence withstand voltage (50 Hz): 250 V



Ex isolating spark gaps - Competitors Comparison DEHN EXFS - HAKEL HGS 100Ex

14.01.08 / 5324e_a


HS 100 ExEXFS 100

EC-type examination certification: BVS 06 ATEX E 099 FTZ 04 ATEX 0255X

Explosion protection - gases: II 2G Ex d IIC T6 II 2GD EEx m II T3


no permission for dusts



Ex isolating spark gaps - Competitors Comparison DEHN EXFS - HAKEL HGS 100Ex

14.01.08 / 5324e_b

2007 DEHN + SHNE / protected by ISO 16016 DEHN UK, 2011 11.12.07 / 5392

For further information about lightning protectionplease visit us on our STAND No. U25

Thank you for your attention

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