What is wood really? And can we install the box in C3? Our answer is:

Currently it is difficult to install the box on or into the C3 materials because the standard ČSN 33 2312 / Z1 provide with respect to ČSN EN 13 501-1 the end of sorting of materials to the degree of flammability and converts this classification into reaction to fire classes. Uncertainty about whether I can install wiring boxes comes from C3 materials, we mention the transfer of C3 flammability materials. We only mention the transfer of C3 flammability grade materials. Since June 2005, these materials have been identified as materials of the reaction class E or F.

The wood has never been in this category. Hard wood, such as beech or oak, was even hardly flammable in the C1 flammability grade. It is understandable that each wood is finally surface-treated and this surface can increase its flammability. In order to avoid similar assumptions, we will always have in mind materials of reaction to fire class F. This classification must be provided by each manufacturer of the construction product.

And now to the standard ČSN 33 2312 Electrical equipment in and on flammable substances. The above-mentioned amendment to Z1 introduces a paragraph in the introductory paragraph of the original standard ČSN 33 2312 of 8.5.1985, which refers to the current validity of this standard together with the standard ČSN EN 60670-1-Box and complete covers for electrical accessories for residential and similar solid electric installation. This standard will replace the standard from 1.10.2007 for the standard ČSN 33 2312. For 7 years now, the wiring box has been complyed with another standard than the electrotechnical public think about.

Classification 7.2 according to the method of installation - 7.2.1 Embedded, semi-enclosed or put in 7.2.1.2 such as flammable walls, flammable ceilings or flammable floors to be followed by sorting according to 7.2.1.3, such as hollow walls, hollow ceilings, hollow floors or furniture. We have mentioned these sorts just because KOPOS KOLIN a.s. produce wiring boxes into hollow wall (in ocher color), tested and classified according to these classifications. From the 850 ° C flaming loop test and the above classification, we can clearly recommend mounting on wiring boxes into hollow walls to materials of reaction to fire class F.

And because, according to the standard, there is no more flammable substance, there is no concern about the possibility of installing our boxes into hollow walls on the construction material with any reaction to fire.