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Der Elektro- und Gebäudetechniker

de Special 1-2/2008

ORGAN DES

ZVEH

ELECTROINSTALLATION:

Which cable lug suits which application?

Hüthig & Pflaum Verlag GmbH & Co.Fachliteratur KGLazarettstraße 4, 80636 München

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Electroinstallation

On the German markethundreds of differentversions of cable

lugs are available. For the electrician it is verydifficult to choosefrom this broad rangethe correct cable lugfor each specific app-lication. The followingarticle gives an overview of the different types of cable lugs for copper conductorsand details the facts which willguarantee a safe and long-lastingconnection.

In principle we differentiate bet-ween three types of cable lugs((ppiiccttuurree 11)).

• Compression cable lugs according toDIN 46235

• Standard tubular cable lugs • Sheet metal terminals according to

DIN 46234

Compression cable lugs accordingto DIN 46235

DIN standard 46235 defines the app-lication, dimensions and marking ofcable lugs. This standard allows use ofthese cable lugs for compression ofsolid, stranded, fine stranded and fineststranded copper conductors. The Uti-lities market for instance offer a widerange of applications.

Markings on the product providethe installer with essential informationrelating to the origin and applicationof the DIN 46235 cable lugs, which alsoapplies for standard tubular cable lugs.Marking “KL 22 12 – 150” shows:

• KL: indicates manufacturer (in thiscase Klauke)

• 22: Die code (only for compressioncable lugs DIN 46235)

• 12: Metric bolt size for connectingbolt: size M12

• 150: Cross section of conductor in mm2

In addition, these cable lugs indicatethe number of required crimps ((ppiicc--ttuurree 22)).

For installing, the DIN standard re-commends crimping dies according toDIN 48083, part1, 3 and 4 for solid,stranded and fine stranded conductors.For braided ropes the standard refersto the information of the manufactu-rer. Klauke generally recommends theuse of hexagon crimping dies accordingto DIN 48083, part 4 for installing of

compression cable lugs DIN46235. Range of cross section is

from 6 mm2 up to 1000 mm2,bolt sizes range from 5 mm up to

20 mm. Electrolytic copper accordingto EN 13600 is mandatory. For corrosionprotection, compression cable lugs –also standard tubular cable lugs andterminals – are tin plated.

Copper tube cable lugs“standard design”

Apart from DIN cable lugs, many manu-facturers also offer standard tubularcable lugs, also made from electrolyticcopper according to EN 13600. As far assizes are concerned, standard tubularcable lugs are mostly shorter than DINcable lugs and also differ in tube

Incorrect tools or anunprofessional crimp can cause

increased temperatures oreven fire.

Small component with a great impact: A poor cable connection can result in an increased joint resistance

and even in fire. We will show you the correct procedure.

Which cable lug suitswhich application?

Source: Klauke

Picture 1: Three types of cable lugs:DIN compression cable lugs, standardtubular cable lugs and sheet metalterminals (from left to right)

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Picture 2: Only DIN compression cablelugs show the required number ofcrimps stipulated by the manufacturer.

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Picture 3: DIN compression cable lugsare longer than standard tubularcable lugs

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Picture 4: Standard tubular cable lugs(left) have different tube dimensionsthan DIN compression cable lugs (right)

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AT A GLANCECable lugs provide safe electricalconnections. We show which cablelug suit which application and whichtool should be used.

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dimensions ((ppiiccttuurree 33,, 44)). However,since these lugs are also subject to teststandard IEC 1238 part 1, durability ofelectrical and mechanical connection isnot affected.

All cable lugs – irrespective of type –can only be crimped properly when a suitable tool is used. Incorrect tools or an unprofessional crimp can result in increased joint resistance, increasedtemperatures and even fire. ((ppiiccttuurree55)). To exclude such consequencesKlauke recommends for crimping oftheir cable lugs the exclusive use oftheir appropriate crimping tools.

Sheet metal terminals accordingto DIN 46234

Also for the sheet metal terminalscertain standards apply regardingapplication, dimensions and marking.Other than compression cable lugs DIN46235 terminals are designed only forcrimping of stranded, fine and very finestranded conductors – not for solidconductors.

Cross section ranges from 0.5 mm2

up to 240 mm2, bolt sizes from 2 mm to 16 mm. Among others terminalsthey can be found in electrical controlcabinets and vehicles of public trans-portation services.

Sheet metal terminals are also madefrom electrolytic copper according toEN 13600. But there is a difference inthe basic material. While compressionstandard tubular cable lugs are pro-duced from copper tubes, terminalsare made from copper sheets. Ter-minals show a soldered seam as theDIN standard prescribes a closed tube.The DIN standard does not specifycrimping tools – Klauke recommendstheir self-designed indent crimpingtools.

Useful information

The selection of the correct cable lugvery much depends on the cable type.For cables according to DIN 57295 thefollowing cable lugs can be used.• Cables class 1, 2, 5 and 6: Compression

cable lugs DIN 46235• Cables class 2: Standard tubular cable

lugs• Cables class 2, 5 and 6: Terminals

In practice it can happen that flexibleclass 5 and 6 cable conductors do not fitinto the appropriate cable lug. For suchcases Klauke recommends the so calledF-cable lugs which have a larger innerdiameter and feature a flared entry.Indent crimping is recommended((ppiiccttuurree 66)).

For installing the DIN cable lugs,crimping tools with die codes accordingto DIN 48083 part 4 have to be used.For tubular cable lugs please refer to the tool recommendations of themanufacturer.

Electrical and mechanicalproperties

The International Standard IEC 1238part 1 applies to electrical andmechanical properties of cable lugs.The requirments for a permanent andsafe electrical connection for theintended application are detailed inthis standard. Both a mechanicalpullout test and an electrical durabilitytest are defined. A test cycle simulatesthe application in practice: The con-nection is being heated 1000 times up to 120° C, to imitate the morningvoltage peak in the public powersupply system. Also high current testsare being carried out at temperaturesof 250° C.

Electroinstallation

MORE INFO:

For more literature on thesesubjects please got to

http://www.vde-verlag.de/engl.html

Picture 5: Incorrect and correct crimps in comparison: An incorrect crimp (left:excess crimping, middle: low force crimping,and usage of incorrect crimping tools can result in an increase in joint resistance and may jeopardise the installation; right: correct crimping)

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Picture 6: F-Cable lugs with flaredentry represent an option whencables of class 5 and 6 will not fit intonormal cable lugs.

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Picture 8: High quality Klauke cablelugs (above) show a clean and verticaltune end

Picture 7: The longer tube of Klaukecable lugs (above) guarantees a highquality connection.

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The responsibility of adherence to these safetyrules lies with every manufacturer of cable lugs. Forthis reason the manufacturers specify theappropriate cable type to be used with their cablelugs.

Apart from normative standards, renownedmanufacturers stipulate additional quality re-quirements. Klauke made cable lugs are subject to an“annealing” process to condition the material fromtension and hardness and to reduce the risk offracture. This process increases the durability andprovides greater protection for the lug againstvibration. This is another reason why we onlyrecommend use of high-quality cable lugs from wellknown manufacturers ((PPiiccttuurree 77)).

The quality of cable lugs can often be recognizedby visual characteristics. A burr free lug, a flat palmand a cleanly machined end are signs of a highquality product ((PPiiccttuurree 88))..

Preview: Cable lugs for special applications

Cable lugs per this article comply with nearly allstandard requirements of day-to-day practice. Agreat number of applications, however, for instancesolid conductors or connections in switch cabinetsrequire special cable lugs. These will be featured inour next issue.

Lutz Remmel, Anwendungstechnik & Application Engineering,

Gustav Klauke GmbH, Remscheid

Crimping, cutting and punching with the same tool at an ambient temperature from -20° up to 40° – innovation at it’s best.

A flip-top style universal head allows easy and fast

change of adapters and dies for multiple applications.

The head rotates 360° and features a two stage hydraulic

system – for your convenience. With the built in quick

stop and automatic retraction once the crimping cycle

is complete, you can rely on the Klauke Multi to provide

a safe solution.

For more information please visit www.klauke.com

Hot or cold between –20° and 40° – the Klauke Multi.

RZ_KLAUKE_100x297_multi.indd 1 19.06.2008 12:00:50 Uhr