BS7609 & BS7727 The British Standards

Our Elpress terminals comply with...................

BS7609:1992+A2:2009
Code of practice for installation and inspection of uninsulated compression and mechanical connectors for power cables with copper or aluminium conductors

BS7727:1994
Code of practice for installation and inspection of pre-insulated compression terminals and connectors for cables with copper conductors up to 6 mm² (10AWG)

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Crimping Systems to BS7727 & BS7609

What is crimping?
A way to, with a suitable tool and through high force, crimp a metal terminal to give a permanent deformation around an electrical conductor, to achieve good electrical connection.


Different crimp shapes and forms

Hexagonal crimping for tubeshaped necks •Gentle on the wires/strands of the conductor •Gives good electrical properties •Is used on both Cu and Al
Indent crimping •May be hard on the wires/strands of the conductor •Is used primarily on Cu conductors
Punch-Matrix crimping •Has great oxide breaking properties which is necessary on Al conductors •Maintains, due to the matrix, high inner pressure during the crimping operation •Is used on Al

What is BS7727:1994?
BS7727:1994
Code of practice for the installation and inspection of pre-insulated compression terminals and connectors for cables with copper conductors up to 6mm²

What is BS7609:1992+A2:2009?
BS7609:1992+A2:2009
Code of practice for the installation and inspection of un-insulated compression and mechanical connectors for power cables with copper conductors of 10mm² and above, or aluminium conductors of 16mm² and above

What are the intentions?
Both codes of practice intend to give guidance to manufacturers and contractors who use compression and mechanical connectors to enable cables to be terminated using good engineering practice and to provide quality control guidance for the tooling.

”all terminals looks the same”
”there are a lot of tools to use”
”this has always worked”   Etc.

What are the requirements for connectors?

Markings
Reference on the barrel or palm to enable user to choose correct size and type.

It should allow correct die and tool to be selected from manufacturers list.

Careful attention to the position of die head on barrel and number and order of compressions if multiple.

Covers preparation of copper and aluminium conductors.


A) Conductor area
B) Logotype
C) Stud size
D) Die id.-number(system identification)
E) Die number imprint


The international standard BS EN60228 specifies the nominal cross sectional area for conductors in electrical cables.

Requirements for numbers and sizes of wires and resistance values are also specified.

Different types

–Solid (BS EN60228 Class 1)
–Stranded (BS EN60228 Class 2)
–Flexible (BS EN60228 Class 5)
–Highly Flexible (BS EN60228 Class 6)

Most conductors meet the requirements of BS EN60228, (IEC 228), which gives the max resistance per km. This means that a nominal 95mm² conductor does not necessarily have to have this exact cross section area (CSA) as long as the resistance is sufficiently low to meet the standard. The cable manufacturer can benefit from this by using a lower resistivity material and a smaller CSA.



Is this ok? (see arrow)




Rather large clearance in
Elpress KRF-terminals!

This terminal type is designed for both stranded and flexible conductors.

It therefore has a wider neck and is crimped more than a type that only can take stranded conductors.



Hence the answer: Yes!



Various compression results



It is very difficult to visually see that there is far too small cross section area reduction.

When crimp systems are mixed - the result is normally a decrease in functional margins.

If there is a mix - how shall the end user see this?

Various compression - > 10mm²





Properties after crimping eg1







Properties after crimping eg2

Properties after crimping eg3

Properties after crimping eg2 & eg3




Properties after crimping - summary




General Inspection

Correct reference relative to conductor size
•Stranded or Flexible conductor
•Correct die has been used
•Free from flash or burrs –detrimental to performance
•No insulation in the barrel
•Excess grease is wiped off cable and connector
•If inspection hole on lug, check conductor is fully inserted


Mechanical Inspection

•Preparation of Conductors
•Assembly of Connectors
•Inspection of Mechanical Connections
•Bolting of terminal lugs to equipment
•Preparation of surfaces on connector palms and equipment
•Bolting of connections
•Connections between the same metals
•Connections between dissimilar metals
•Recommended torque wrench settings for aluminium and copper

Maintenance/Service/Calibration

•Tooling should be certified by an authorised body before being used and then periodically, (NOT exceeding 12 months), or, if doubts arise as to the quality of the crimping performance. Tools and associated parts should be numbered for identification and records of repair, performance and certification kept in a file by the user

•Tools and associated parts should be numbered for identification and records of repair, performance and certification kept in a file by the user

•Inspect hose and hose connections

•Check that there is no leakage in the pump, connections or press-head

•Inspect the electrical cable and accessories

•Inspect quick coupling on press-head

•Polish the surface on the dies by using a soft polishing cloth or abuffing wheel together with some polish

•Keep everything clean

•Check the pressure in the pump with a pressure-gauge

•Check the oil-level in the pump

•Inspect hose and hose connections - Check that there are no leaks in the pump, connections or press-head - Inspect the electrical cable and accessories - Inspect quick couplings on press-head - Polish the surface on the dies by using a soft polishing cloth or a buffing wheel with polish - Keep everything clean - Check the pressure in the pump with a pressure gauge - Check the oil-level in the pump

Why choose a systemised approach?

All manufacturers optimise the interaction between crimp necks and crimp dies - but not in the same way! Designs differ heavily.
 
System designs have marks and engravings to show that the proper system components are used.
 
System crimps can be checked in accordance with measure tables (crimp heights, etc)
 
Non-system settable tools are totally depending on the operators ability, strength, interest etc.
 
Consequently the total quality assurance (i.a ISO9000) required by customers today leaves no alternative to the use of a matched system of crimp tools and connector elements.

The system includes:-

•The tube terminal or through connector

•The crimping tool

•The conductor

•Trained operator

•The instructions
 

THE Most Important component in a Quality Crimping System is…..???

The Trained Operator!!

Why choose Elpress UK?

0.1mm² up to 1200mm²


Who has chosen the Elpress UK Crimping System?
•ABB
•Siemens
•Areva
•Ericsson
•Nokia
•Bombardier
•Alstom
•Vestas
•BNFL
•BP
•Shell
•Chevron
•Exxon Mobil
•Saudi Aramco
•Qatar Petroleum
•Crown House Technologies

Some of the OGP Projects
•Shell Shearwater
•BP Andrew
•Shell Bonga
•Sakhallin
•Ras Lafan
•Sohar Aluminium Smelter – OMAN
•Dubai Metro
•TengizChevron
•Texaco Captain (Chevron)
•Borouge 2 – Adnoc (Abu Dhabi)

•Design Houses that have Specified Elpress Include:
•Bechtel
•Foster Wheeler
•Worley Parsons
•Haliburton – KBR
•Fluor

Can all of these be wrong?

and because otherwise, this can happen...



For more information, visit our new site:
BS7609 & BS7727: British Standards for Crimping