Abschnitt 4.10 - 4.10 Measures for protection against electrical hazards
Owing to the characteristics of vessels, silos and confined spaces (in particular the access situation, materials used in their construction, and freedom of movement within them), an increased electrical hazard must generally be assumed (=> protective measures under circumstances of constrained freedom of movement in a conductive environment).
4.10.1
Operation of stationary electrical equipment
One of the following measures must be taken when stationary electrical equipment is used:
Safety extra-low voltage (SELV). Only Class III equipment may be used; irrespective of its rated voltage, such equipment must feature ingress protection of at least IP2X, i.e. be isolated or shrouded to be fingerproof.
Protective separation. Only one item of current-consuming equipment may be connected per secondary winding of an isolating transformer or motor generator (refer to DGUV Informative publication 203-032 concerning the selection and operation of power generators on construction and installation sites). The windings must be galvanically isolated from each other.
Protection by automatic disconnection of the power supply. Where Class I items of equipment are used, their enclosures must be fitted with supplementary local potential equalization. Residual current devices with IΔn ≤ 30 mA must be used for automatic disconnection.
4.10.2
Operation of mobile electrical equipment
One of the following measures must be taken when mobile electrical equipment is used:
Safety extra-low voltage (SELV). Only Class III equipment may be used; irrespective of its rated voltage, such equipment must feature ingress protection of at least IP2X, i.e. be isolated or shrouded to be fingerproof.
Protective separation. Only one item of current-consuming equipment may be connected per secondary winding of an isolating transformer or motor generator. The windings must be galvanically isolated from each other.
Hand-held lamps may be operated only with safety extra-low voltage (SELV).
4.10.3
Mobile sources of electrical power must be situated outside the area presenting an
increased electrical hazard.
Should this not be possible for technical reasons (e.g. in the case of very long pipelines, sewers, box girders, etc.), the electrical power source (i.e. the isolating transformer) may be situated on a case-by-case basis within the area presenting an elevated electrical hazard provided the supply line meets the following requirements:
The manner of its routing protects it against damage, and it is of type H07RN-F or H07BQ-F
It is operated through an RCD with IΔn ≤ 30 mA
4.10.4
Mobile electrical equipment should ideally be of Class II only. Mobile isolating and safety transformers must satisfy Class II.
The provisions of this section do not apply to mobile items of equipment with their own electrical power source.
Examples of such equipment are cordless screwdrivers and battery-powered lamps.
If an increased electrical hazard can reliably be prevented from arising, measures in accordance with good practice on construction and installation sites (see DGUV Informative publication 203-006 governing the selection and operation of electrical installations and equipment on construction and installation sites) are sufficient in derogation from the provisions of Section 4.2.
The actual work situation, i.e. the tasks to be performed in consideration of the conditions of the working environment, must be taken into account by the assessment.