Where installations are subject to the conditions of fauna or flora and/or mould growth, wiring systems and other equipment of an installation are required to be appropriately selected and installed. (Regulation Groups 512.2, 522.9 and 522.10 of BS 7671).
The term ‘fauna’ (animal life) includes insects, small animals and birds.
Examples of flora (plant life) include plants, trees and other forms of vegetation.
Mould may also have to be taken into consideration.
All electrical installations subject to external locations, as well as in some internal locations (such as greenhouses), may be exposed to fauna or flora and/or mould growth that could impair safety or functionality of the installation.
As with all external influences, you should avoid installing electrical equipment where it will be exposed to adverse effects. For i.e. distribution equipment supplying outdoor installations should, where practicable, be installed in an indoor location or have a suitable IP rating.
If not suitably selected or adequately protected, equipment enclosures installed in contact with the ground (or buried in it) might become infested by insects.
Damage to cables from the gnawing of small animals i.e.rats, mice and squirrels etc. is a relatively common occurrence. All types of cable, for example, thermoplastic (pvc), rubber and lead sheathed and even steel wire armoured cables, seem susceptible to attack, resulting in exposure of the conductors.
Where conductors exposed by the gnawing action are surrounded by rodents’ nesting materials, which are generally combustible, there is a risk of fire. This is in addition to the obvious danger of electric shock to persons from direct contact with an exposed live conductor.