The plant may be not so damaged or total in the functioning have deteriorated, that there is a risk of security. The proper condition of the electrical system must always be maintained by the electrician. Are either detailed recurrent checks required or continuous monitoring of the system and its resources. The responsible qualified electrician can partially without recurring inspections through preventive maintenance and detailed documentation of all processes or increase the periodic check-up. In establishments where no continuous monitoring of electrical systems and equipment can be done, repeat tests are used at set intervals. The deadlines among others depending on the type of service. Factors such as the temperature, humidity or pollution have a significant impact on the State of an electrical appliance and thus also on the frequency of the checks.

How high the A plant load factor is, is determined on the basis of an operational risk assessment. Sufficiently often tested electrical equipment and installations are, if their margin of error is less than 2%. The inspection periods differ also on the basis of the type of electrical equipment and installations. As already mentioned, a distinction between mobile and stationary electrical equipment as well as stationary and non-stationary systems takes place in the accident prevention regulations of GUV-V A3. Portable electrical equipment portable electrical devices are, for example, hand-held tools, computer, extension cable, mains leads, floor lamps or even household appliances such as coffee makers. These can be easily, even while the device is operating, moved or brought to a different place. They are connected to the supply circuit. Depending on the type of the institution and intended use of the electrical equipment, apply different inspection periods: test period of 6 Months kitchens for catering/canteen kitchens: kitchen appliances such as toasters, slicers, hot plates, coffee machine slaughterhouses: electrically operated saws and knives baths: underwater vacuum cleaner, water cleaner, centrifuge test period by 12 months laboratories: Netzbetriebene laboratory equipment, measuring devices, portable analyzers fire brigades: hand lamps, floodlights, transfer pumps cleaning: carpet cleaning equipment, vacuum cleaner, floor – and brush devices classrooms in schools: Beamer, extension and appliance cords laundries: sewing machines, irons and machinery workshops/building sites: mixers, angle grinder, Jig Saws, aerators, lawn mower, shredder test period of 24 months of office operations: Text and data processing systems, overhead projectors, fans, photocopiers and mobile booking machines, dictaphones nursing stations/home: shavers, electric Handheld devices, hairdryers, Frisierstabe, red light lights, table lamps extreme environmental conditions such as high humidity, for example, in the waste water or bathing area, a strong mechanical stress, as well as particularly high or low temperatures can lead to a shortening of the test distance.