Cable Cleats IEC 61914 - What The Standard Means And How To Choose Compliant Cleats

What Does IEC 61914 Not Cover?

IEC 61914 does not apply to cable ties or cable glands. This is an important point for specifiers.

A cable tie cannot be "IEC 61914 compliant" as a cable cleat, so ties should not be relied on to restrain cables against short-circuit forces where a tested cleat is required.

How Does IEC 61914 Define A Cable Cleat?

IEC 61914 defines a cable cleat as a device with a means of attaching to a mounting surface, designed to secure cables when installed at intervals along their length.

Where declared, the cleat also gives resistance to electromechanical forces.

An intermediate restraint is defined separately. It is a device used with cable cleats, but not fixed to the mounting surface, to hold cables in formation between cleats and add short-circuit resistance.

Which Edition Of IEC 61914 Is Current?

The current edition is IEC 61914:2021, the third edition. It replaced the 2015 second edition, which itself replaced the original 2009 edition.

In the UK the standard is published as BS EN IEC 61914:2021, which is identical to IEC 61914:2021 and supersedes BS EN 61914:2016.

Before IEC 61914, cleats in Europe were covered by EN 50368:2003, which has since been replaced by the IEC standard.

What Changed In IEC 61914:2021?

The 2021 edition brought in clearer mandrel requirements for testing, test rules for MV and HV cables, new corrosion classes for plated products, and new tests for marking durability.

It also added axial load testing for cleats holding more than one cable, and lateral load testing for intermediate restraints.

It defines LV cables as those rated at 1.0kV AC or 1.5kV DC or less, and MV and HV cables as anything above that. This matters because short-circuit tests can now be carried out with higher voltage cables that better reflect the real installation.

Classification By Material (Clause 6.1)

Cleats are classified as metallic, non-metallic or composite.

In our range, metallic cleats include the Ellis Patents Alpha Aluminium Trefoil Cleats (Aluminium Base), the Prysmian Orion Aluminium Cleat (Standard) and the Prysmian Tetrad Cleat 381 Series in 316L stainless steel.

Non-metallic cleats include the Prysmian Plastic Two Bolt Cable Cleat (Standard) and the Ellis Patents Single Way Fixing Cable Cleat.

Composite designs, which combine a metal body with a polymer part, include the Ellis Patents Alpha Aluminium Trefoil Cleats (LSF Zero Halogen Base).

Classification By Temperature (Clause 6.2)

Each cleat is given a maximum and minimum temperature for permanent use, chosen from set values in the standard.

The maximum values are +40°C, +60°C, +85°C, +105°C and +120°C. The minimum values are +5°C, −5°C, −15°C, −25°C, −40°C and −60°C.

Manufacturers can declare figures outside this range where needed.

Temperature matters most for non-metallic and composite cleats, because polymers lose strength as they get hotter.

Classification By Impact Resistance (Clause 6.3)

Cleats are classified by impact resistance as very light, light, medium, heavy or very heavy.

A higher class means the cleat has passed a more severe impact test. That matters on sites where cleats could be struck during installation or later maintenance work.

Classification By Environmental Influences (Clause 6.5)

Cleats can be classified as resistant to ultraviolet light (for non-metallic and composite parts) and resistant to corrosion (for metallic and composite parts).

UV resistance is critical for outdoor polymer cleats. The Prysmian Plastic Two Bolt Cable Cleat (Afumex LSOH) is described as resistant to sunlight, weather, oils and most chemicals.

For corrosive sites we also stock epoxy coated cleats such as the Prysmian Orion Aluminium Cleat (Epoxy Coated) and the Prysmian Aluminium Two Bolt Cleat (Epoxy Coated).

Classification By Electromagnetic Compatibility (Clause 6.6)

Cleats are classified as either liable or not liable to inductive heating.

Ferrous metals that fully surround a single-core AC cable can heat up from induced currents. This is why trefoil cleats for single-core cables are usually made from non-magnetic materials such as aluminium, non-magnetic stainless steel or polymer.

Our aluminium trefoil options include the Ellis Patents Alpha, Prysmian Orion and Prysmian Libra Aluminium Cleats.

What Has To Be Declared For The Test?

The manufacturer must declare the peak short-circuit current (ip), the initial RMS symmetrical short-circuit current (I"k), the cleat spacing and the cable arrangement used.

The 2015 edition also added a declaration of the distance between cable centres. These figures are what you compare against your own design.

A rating such as 96kA peak is only meaningful alongside the spacing and cable diameter it was tested with.

What Counts As A Pass?

To pass, the cleats and any intermediate restraints must stay intact with no missing parts (minor deformation is allowed), and the cables must stay secured without damage that would affect their safety.

For the higher classification, the setup must survive a second short circuit and then pass an AC or DC voltage test. This proves the cable insulation has not been damaged by the cleats.

What Do The Lateral And Axial Load Tests Involve?

The lateral load test applies the manufacturer's declared load to a test mandrel held in the cleat.

The axial load test pulls the mandrel along its length to check it does not slip more than a set amount. Both tests use mandrels that represent the cable sizes the cleat is designed for.

Non-metallic and composite cleats are tested at their maximum declared temperature, because that is when polymers are at their weakest.

Start With The Prospective Fault Current

The peak short-circuit current (ip) of the circuit is the key number, because the cleat's declared rating has to be at least this high.

Short-circuit force rises with the square of the current, so a small increase in fault level makes a big difference to the force the cleat must hold.

Match The Tested Spacing

Install cleats at or closer than the spacing used in the manufacturer's IEC 61914 test.

A cleat that passed at 600mm centres has not been proven at 900mm. Closer spacing lets the run withstand higher fault currents.

Match The Cable Formation And Diameter

Use the cleat in the same formation it was tested in (single, trefoil or quad) and within its declared diameter range.

A cleat that is too large will not grip properly, while one that is too small can damage the cable sheath.

Our cable cleat size chart matches overall cable diameter to the correct cleat size.

Check The Marking And Documentation

Every cleat should be marked and backed by documentation that states its IEC 61914 classification.

The 2021 edition added tests for marking durability and legibility, so markings stay readable throughout the life of the installation.

Do Cable Ties Need To Meet IEC 61914?

No, cable ties are outside the scope of IEC 61914, so a tie cannot be classified as a cable cleat under this standard.

Ties are still very useful for bundling and tidy cable management alongside cleats. We stock a full range in our cable ties category.