Electrical current

Electrical current
(common for various works
and activities)
General information.

Problem : Threat of electrocution by:
- the electricity installation
- (cables)
- fittings (sockets, switches)
- panels (distribution panels)
- distribution boxes
- electrical plant and machinery powered by electricity (fixed and portable)


Questions / observations
Activities improving the state of OSH

Are periodic controls of the effectiveness of electrocution protection and the state of insulation of the cables held? Periodically (once a year, according to the Construction Law) inspect the effectiveness of the electrocution protection and the state of insulation of cables; eliminate possible irregularities.  

Are examinations and repairs of electrical equipment and installations conducted by qualified personnel?   Only allow an electrician with a qualification certificate, with appropriate qualifications for the equipment used and the voltage of the supply to examine, repair and make the connections.

Repairs and maintenance of electrical equipment should only be conducted after switching off the power supply.

Are electrical devices and installations used which are incorrectly selected for the working conditions (including fuses and circuit breakers)

    • with damaged or repaired insulation (i.e. bare wires)

    • with temporarily connected receivers

    • with defective sockets and plugs

    • with open casings of the electrical equipment or not secured against opening by unauthorised personnel

    • with open covers to electrical casings clamped shut

    • with light fittings having disassembled, incomplete or damaged bowls?
Use electrical fittings and cables marked with the safety sign and with a current certificate authorising the marking with such a sign in accordance with its assignment.

Prevent mechanical damage to electrical cables (suspend cables, lay cables in a protective sheath, e.g. cable trays, conduits etc.).

Connect electrical devices and cables permanently (avoid temporary connections and installations), Close electrical fittings in a housing of sufficient mechanical strength and degree of IP protection that is appropriate to the conditions of use, (this also refers to light fittings)

Prevent the opening of cabinets and clamped boxes by unauthorised personnel with technical and organisational measures. Use portable electrical devices (lamps) powered by a safe voltage (24 V)* with safety transformers manufactured under class II safety

Do not use equipment when damp, or when the supply cables are lying in water.

Describe and mark electrical installations

Do the distribution panels, clamped machine boxes and control housings contain warning and information signs and diagrams? (combination of yellow and green reserved for the protective wire and balancing connections, blue for neutral).

Fit the machines and equipment with a clearly marked and easily accessible power switch.

Include the circuit diagram within the distribution box

Is the electrical installation fitted with protective circuit breakers? Use circuit breakers in the installations (in old installations, fuses with fuse wire) with parameters that are consistent with the design of the installation.

Replace (not repair) the fuse wire inserts of the fuses in which the fuse wire has melted

Are separation transformers used in the installation? Class II protection separation transformers of a ratio of 1:1 should be used for protection against electrocution under conditions of particular threat

Are the installation and the connected machines fitted with a system of balancing devices? Use balancing devices between installations and metal components of the equipment in the work premises.

Are there explosion hazards zones? Mark the explosion hazard zones.

Is the installation that is used in explosion hazard zones produced in an explosion-proof version? Use installations and equipment only manufactured according to the requirements of the protocol that classifies the zone as an explosion hazard zone.



See also:


Module of the STER System supporting selection of personal protective equipment