Competent Person
A competent person has, through their vocational training, professional experience and recent occupational activity, the necessary specialist knowledge to inspect work equipment (TRBS 1203,
full text in the TRBS directory). For electrical inspections, they are usually also a qualified electrician. The employer must assess and document the qualification on a case-by-case basis.
Qualified Electrician (EFK)
A qualified electrician has, through their professional training, knowledge and experience, the ability to assess work assigned to them and to recognize possible hazards (per DIN VDE 1000-10 and DGUV Information 203-002). They bear technical responsibility for electrotechnical activities.
Electrotechnically Instructed Person (EuP)
An electrotechnically instructed person has been informed and, if necessary, trained by a qualified electrician about the tasks assigned to them and the possible hazards of improper conduct. They may only carry out simple, clearly defined tasks under guidance, but may not make independent technical assessments.
Responsible Qualified Electrician (VEFK)
The VEFK is a qualified electrician to whom the employer has, in writing, assigned responsibility for compliance with electrotechnical rules in a specific area. They act independently within the scope of this assignment and are the point of contact for all electrotechnical questions in their area of responsibility.
Visual Inspection
During a visual inspection, an electrical item of equipment is examined externally for recognizable defects — damaged housings or cables, missing covers, unauthorized repairs, or visible overloading. It precedes every measurement and function test; if defects are found, further testing can be skipped, since the device is considered to have failed anyway.
Protective Conductor Resistance
Protective conductor resistance is the electrical resistance between the earthing contact of the mains plug and the accessible conductive parts of a protection class I device. It must be below a limit value defined in the respective test standard, so that in the event of a fault the fuse can safely trip.
Insulation Resistance
Insulation resistance describes how well the live (current-carrying) parts of a device are insulated from accessible housing parts. A value that is too low indicates damaged or aged insulation, and thus an increased risk of electric shock or short circuit.
Substitute Leakage Current
In the substitute leakage current method, a device's leakage current is not measured under real operating voltage, but instead calculated using an alternative, safer measurement procedure. This is especially practical for on-site inspections, since the device does not need to be connected to the mains for it.
RCD / RCCB (Residual Current Device)
An RCD (Residual Current Device, colloquially 'FI' in German) monitors the current flow between conductors and trips as soon as a differential current (residual current) exceeds a defined limit — for example because current flows to earth through a person. It then automatically and quickly disconnects the supply and is a key protective measure against electric shock.
Function Test
During a function test, it is checked whether a device or protective device — such as an RCD via its built-in test button — actually works the way it should. It complements the measurement test, since some faults (e.g. a defective tripping mechanism) cannot always be detected by measurement alone.
Initial Inspection
The initial inspection takes place before an item of electrical equipment is put into service for the first time, and after every repair or modification. It ensures that the device, whether new or after the intervention, meets the required safety standards before it is used on a regular basis.
Recurring Inspection
The recurring inspection is the regularly repeated inspection of an item of electrical equipment already in use. The interval depends on the device type, operating conditions and the workplace risk assessment, and is usually documented on the test label.
Portable Electrical Equipment
Portable equipment is moved during operation or, while still connected to the supply network, can easily be taken from one place to another — for example drills, extension cables, coffee machines or laptop power supplies. DIN EN 50699 generally applies as the test standard for this equipment.
Fixed Electrical Installation
A fixed electrical installation is permanently installed and is not moved during normal operation — such as distribution cabinets, hard-wired machines, or a building's electrical installation. It is inspected in accordance with DGUV Regulation 3 and the relevant DIN VDE standards for fixed installations, not according to the standards for portable equipment.
Protection Class I
Protection class I devices have basic insulation and, in addition, a protective conductor connection that, in the event of a fault, connects accessible conductive parts to earth — recognizable by the earthed plug (Schuko in Germany). Protective conductor resistance is a key test value for these devices.
Protection Class II
Protection class II devices are protected by double or reinforced insulation and do not require a protective conductor. They are recognizable by the symbol of a square within a square on the rating plate — for example many chargers and power tools.
Protection Class III
Protection class III devices are operated exclusively with extra-low safety voltage (SELV, typically up to 50 V AC / 120 V DC), where a dangerous electric shock is largely ruled out by the low voltage itself.
Test Interval
The test interval determines how often an item of electrical equipment must be recurrently inspected. It is set by the employer based on the risk assessment; DGUV Information 203-070 and 203-072 provide guidance values, depending among other things on operating conditions and the prior fault rate.
Risk Assessment
The risk assessment is the systematic identification and evaluation of hazards in the workplace, mandatory under Section 5 of the German Occupational Safety and Health Act (ArbSchG). It is, among other things, the basis for how an employer sets the test intervals for their electrical equipment.
DIN EN 50678 (VDE 0701)
DIN EN 50678 (VDE 0701) governs the testing of electrical devices after a repair or modification. In 2021 it replaced the older, combined standard DIN VDE 0701-0702 (finally withdrawn on 21 September 2023) for this application; for recurring inspection during ongoing operation, DIN EN 50699 applies instead.
DIN EN 50699 (VDE 0702)
DIN EN 50699 (VDE 0702) is the current standard for the recurring inspection of portable electrical equipment during ongoing operation. In 2021 it replaced the older, combined standard DIN VDE 0701-0702 for this application; in everyday use the old designation 'VDE 0701-0702' is still common, referring to essentially the same test procedure under the current state of the standards.
Ordinance on Industrial Safety and Health (BetrSichV)
The Ordinance on Industrial Safety and Health gives concrete form to the Occupational Safety and Health Act for the handling of work equipment and installations subject to monitoring. Among other things, it obliges employers to keep work equipment — including electrical equipment — in a technically safe condition and to have it inspected regularly. The duty to carry out a risk assessment itself is set out in Section 3 BetrSichV, and the employer's basic duties in Section 4 BetrSichV.
Formal Inspection & Technical Inspection
TRBS 1201 distinguishes between two types of inspection: the formal inspection establishes whether the required documents (operating instructions, earlier test records, documentation) are present and plausible. The technical inspection comprises visual inspection, testing and measurement of the actual condition, including, if necessary, disassembly and a thorough function test. Only both together result in a complete inspection compliant with TRBS 1201. More on this in the
TRBS 1201 document.
Recognized Rule of Technology
DIN VDE standards are, legally, not laws but recognized rules of technology — which is why you often read "is recommended" instead of "is required." In practice this means: if a business follows the recognized rules of technology, that speaks, in a dispute, for careful conduct. If it deviates from them, the burden of proof tends to shift — the business then has to be able to explain why its solution was nevertheless at least as safe. In practice, then, a "recommendation" is not "optional without consequences."
Test Report
The test report documents a completed inspection: measured values, test result, date, the person who carried it out, and the next test date. It serves as evidence for the employer's liability insurance association, the insurer, and in the event of an inspection or a claim.
Test Label
The test label is affixed visibly to the device after a successful inspection and shows the test date or test status, usually along with the next due date. Modern versions also include a QR code, through which the digital test status and the device record can be retrieved.
Qualified Electrician for Specified Activities (EFKffT)
An EFKffT is theoretically trained, practically instructed and explicitly appointed for clearly defined, recurring electrotechnical activities. They may only carry out the specified activities — an EFKffT is therefore not automatically qualified for all electrotechnical work, unlike a fully qualified electrician.
Electrotechnical Layperson
An electrotechnical layperson may generally not independently operate, open, modify, test or repair electrical installations. Only expressly approved activities without electrical hazard are permitted, such as using intended operating controls or replacing a lamp according to workplace instructions.
Installation Operator
The installation operator bears overall responsibility for the safe operation and condition of an electrical installation. They do not need to be a qualified electrician themselves, but must select and appoint suitable responsible persons and organize safe operation of the installation.
Installation Manager
The installation manager is responsible, during work, for the safe operation of the affected electrical installation or part of the installation. They assess the condition of the installation, define switching states, release the work site, and coordinate recommissioning.
Work Manager
The work manager is directly responsible for the safe execution of the work at the work site. They instruct the employees, supervise the work, and ensure that all defined protective measures are followed.
Under Direction and Supervision
"Under direction and supervision" means that a qualified electrician instructs the work, supervises its execution, and can at any time satisfy themselves that it is being carried out safely and correctly. They do not need to stand right next to the work continuously, but must be able to intervene if necessary.
Authorized Switching Person
An authorized switching person is a person specifically selected, instructed and appointed for this purpose, who may carry out certain, clearly defined switching operations. The scope and limits of the switching authorization must be clearly defined — it is not a general permit for all electrotechnical work.
Independence of the Qualified Electrician
The qualified electrician must be able to make their technical assessment independently. Economic, time-related or hierarchical constraints must not lead to a technically necessary protective measure being omitted — instructions that compromise safety must not be followed.
Five Safety Rules
The five safety rules must be applied in this order when working in a de-energized state: disconnect, secure against reconnection, verify absence of voltage, earth and short-circuit, cover or fence off adjacent live parts.
STOP Principle
The STOP principle describes the ranking of protective measures: S (Substitution — replacing the hazardous activity or work equipment), T (technical measures such as covers), O (organizational measures such as work instructions), P (personal protective equipment). Technical and organizational measures generally take precedence over purely person-related ones.
Danger Zone
The danger zone is the area around live parts where, if entered without suitable protective measures, the necessary safety against electrical hazards is not ensured. Its size and assessment depend, among other things, on the voltage, the working method, and local conditions.
Electric Arc
An electric arc is an electrically conductive discharge through air or another gas. It can produce extreme temperatures, intense radiation, pressure waves, molten metal splashes, noise and toxic fumes, and is one of the most dangerous events that can occur during work on electrical installations.
Electrical Accident
An electrical accident is an accident in which electric current, electric voltage or an arc endangers or injures a person — possible effects range from muscle cramping and respiratory arrest to cardiac arrhythmia and burns. After an electrical accident: prioritize your own safety, disconnect the circuit, call emergency services, and give first aid.
Accident Prevention Regulation
Accident prevention regulations are binding regulations of the statutory accident insurance, which the employers' liability insurance associations (Berufsgenossenschaften) may issue as autonomous law under Section 15 SGB VII. For electrotechnology, DGUV Regulation 3 'Electrical Installations and Equipment' is especially relevant.
