Prysmian UK's Guide to CPR
It's been over two years since the Construction Products Regulation (CPR) came into effect, yet there is still confusion over the minimum class of cable that should be used to meet the requirements of the CPR.
CPR makes it a legal requirement that all cables intended for permanent installation in buildings are classified by their reaction to fire – unless it is a fire resistant cable.
CPR Cable Compliance
To be CPR compliant, a cable must have a Declaration of Performance (DoP) available to demonstrate that it has been tested and certified by an independent testing house which will have allocated it to one of 7 Euroclasses, depending on its ability to spread flame and release heat. Cable labels must display a CE mark for CPR, it should not be on the cable. Cables are rated from A-rated cables that make no contribution to fire, down to F-rated cables which make a very high contribution to fire.
In addition to these main criteria, the Euroclass definition includes three additional criteria: whether a cable produces flaming droplets (subscript d); how much smoke is produced (subscript s); and the acidity of the combustion gases (subscript a). It is worth noting that all Euroclasses are followed by subscript ‘ca’, this simply shows that the Euroclass classification is related to cables. For LSOH (Low Smoke Zero Halogen) cables it is important to request the smoke (subscript s) and acid (subscript a) levels to confirm the cable’s legal status.
When selecting cables it is important to understand that the CPR relates only to the performance of cables in reaction to fire. It does not say how and where a particular product should be used and neither does it say what class of cable should be used in any particular circumstance.
To help specifiers and installers understand which Euroclass cable should be used for common applications, Prysmian has now published its official guidance.
For all installed cables Prysmian recommend a Euroclass Eca cable should be adopted as an absolute minimum. As a general rule, Prysmian would expect this Euroclass cable to be suitable for most low risk applications, such as for power cables in a domestic house.
Where higher fire risks exist, such as in a public buildings or where large bunches of cable are installed, Prysmian strongly encourage the use of a higher Euroclass cable. Depending on the application, consideration should also be given to restricting the evolution of smoke, flaming droplets and acidic gases.
Whatever the installation, it is important to bear in mind that cable specifiers should consider the whole building and not treat cables in isolation. In particular, when specifying products for larger, taller, and more complex buildings it is critical that decisions regarding fire safety should be taken by fire safety experts.