What is CPR? What does it mean for Network Cabling?

16 November 2018

Construction Products Regulations (CPR) – What is it?

What is CPR?

The Construction Products Regulation is a European Union directive, set out with an intention of making buildings, safer.

It brings us a standard classification system for how construction products react to fire. Categorising them into groups (EuroClasses).

BREXIT

Ahhh, yep it had to be said, oops…

No, Brexit will not affect the implementation of CPR.

Why? Well, CPR provides us with the EuroClasses and how cables should be tested to categorise them.

It doesn’t however, state, what the minimum class of cable should be, for each environment.

However, the 30th November 2017 saw a big change.

BS 6701 (a British Standard) was amended and EuroClass Cca, S1b, d2, a2 was implemented as the minimum class of cable that should be used in a permanent installation.

This has now been written into British Standards, so Brexit is unlikely to have any effect moving forwards.

What does CPR apply to?

In simple terms, any cable that is installed in a fixed installation is required to apply by the Construction Products Regulations.

This could be anything from power cabling to control and communications cabling.

It does, however, not apply to things such as patch leads.

What does it test?

We know that BS6701 has specified Cca, S1b, d2, a2, but what on Earth does that gibberish mean?

CPR specifies that the code is constructed in the following manner:

Propagation & Heat Emission

This test establishes how a cable contributes to the fire.

There is a range between Aca (not contributing) all the way to Fca (undetermined).

B1ca – B2ca provides a minimum contribution to fire.

Whilst Cca, Dca & Eca are combustible and do contribute to the fire from a lower to higher contribution (lower letter means less contribution).

Smoke Emission

The next part of the code is based on the smoke emission properties of the cable.

s1, s1a & s1b both provide little smoke production and a slow smoke propagation.

s2 produces an average amount of smoke and propagation

s3 provides none of the above and is a worst case.

Burning Droplets

Burning droplets are the next thing that the EuroClass classifies.

There are three classifications, d0, d1 & d2.

d0 provides no burning droplets.

d1 provides no burning droplets for more than 10 seconds.

d2 is for cables that do not fit into either of the above criteria.

Acid Gas Emission

During a fire, cables can give off an acidic gas.

The last part of the EuroClass code grades this between a1 and a3.

a1 is for cables that reach a conductivity of < 2,5 μS/mm and pH > 4,3.

a2 is for cables that reach a conductivity of < 10 μS/mm and pH > 4,3.

a3 is for cables that do not meet any of the prior specifications.

Why is it important?

Cables now run everywhere.

With a large number of devices being networked, from users PCs and Telephones to Access Control, Wi-Fi and CCTV.

Network cables have become much more versatile.

And all this doesn’t just mean an increase of copper cabling, to support the growing bandwidth demands, fibre optic cables are increasingly being installed between areas and floors within a building.

What this does provide is a path for fire.

And with standards such as 802.3bt being ratified, your existing copper cabling could be expected to carry up to 100W of power, further increasing the risk of fire if the installed cable isn’t designed for such a use.

What do I need to do?

Everybody is affected by CPR.

Manufacturers are required to ensure their products are tested in accordance to the array of standards.

Specifiers are required to ensure their specifications clearly state the minimum EuroClass, appropriate to the country, standards bodies and ultimately the client.

Installers, like us, need to ensure that what we install is in-line with the specification laid out or where this isn’t present, what the client wants.

If you’re a client or end-user, you should asses using the above, what cable specification meets the requirements of your sector best.

Where you are unsure, please do get in contact and our will be happy to help.

Once you’ve established what classification of cable best suits your needs, ensure that on the completion of the installation you are provided with a Declaration of Performance for the cable. You would expect this as part of your Operations & Maintenance Manual.

What else should be considered?

If you decide to choose a higher EuroClass of cable, it’s important to double check the CSA (Cross-Sectional Area) of the cable.

Usually, the higher the fire rating, the larger the cable.

This can mean in larger quantities, larger cable containment needs to be considered, this is especially important if you have opted for a three-compartment containment system.

Be sure to check with the containment manufacturer.

Why not make everything super safe?

If you think like us, you’re probably asking yourself why not just make everything super safe?

We agree!

However, it does come at quite a cost premium…

Whilst it will depend on the cabling system chosen and your installer, cable costs can be upwards of 40% between Eca & Cca classifications.

This is a huge increase, especially on a larger install.

We feel it’s important to remember that CPR cables are still fairly juvenile and we should hopefully see a reduction in price as time goes on.

Conclusions

It’s definitely clear that CPR isn’t something we can ignore, especially if you want to be standards compliant and ensure the safety of your visitors and staff.

Many cable vendors have re-designed their product lines to accommodate a wide range of CPR Compliant cables.

We think there’s certainly more to come, especially with such a wide range of cables on the market.

If you did want to talk to someone regarding the latest developments or you want a second opinion on what cable suits your needs best, please get in touch with one of our advisors on 01604 422722 or message us via our live chat!