Procedure for a DGUV V3 inspection

The first step is often the most important. Our electrician checks the device for any visible defects. Experience has shown that we can already detect numerous faults at this stage. A trained eye can spot damage that is often overlooked in everyday use.

Typical faults found during visual inspections are:

• Damaged insulation on connection cables (broken cables).
• Defective housings (cracks, missing covers).
• Signs of overheating (burn marks on plugs).
• Missing or damaged strain reliefs on the cable.
• Illegible inscriptions or type plates.

If the inspector finds a defect here, the device is immediately sorted out or marked. It must be repaired before further testing can continue.

This is where our calibrated measuring devices come into play. We check electrical values that are not visible to the naked eye. Different standards apply depending on the type of device (stationary or portable). For portable devices, this is DIN VDE 0701-0702, and for stationary systems, it is often DIN VDE 0105-100.

The most important measurements include:

• Protective conductor resistance: Is the connection to earth intact? Low resistance is vital to ensure that the fuse trips in the event of a fault.
• Insulation resistance: This value is critical for fire protection. If the resistance is too low, leakage currents can flow. These generate heat. This often leads to smoldering fires that go unnoticed long before a fuse reacts.
• Protective conductor current / touch current via residual current measurement: Here we measure whether current is flowing through the housing. Will you get an electric shock if you touch the device? Residual current measurement is a particularly accurate method of detecting even small fault currents without having to switch off the device.

Does the device work safely at all? In this step, the inspector operates all switches, controls, and safety devices. Does the emergency stop switch activate as intended? Does the machine stop immediately?

This step ensures that the device is not only electrically safe, but can also be operated without danger. A device that is electrically safe but can no longer be switched off will not pass the DGUV V3 test.

After successful testing, the device receives the familiar round test sticker. It shows the next test date. However, the sticker alone is not legally sufficient. Much more important is the legally compliant test report.

Your advantage with us: Digital report as standard
We create a detailed report for each tested device. All measured values and results are listed there. In the event of damage, this report is your “life insurance” vis-à-vis professional associations and insurers. We provide you with this data digitally (as a legally compliant PDF or Excel list). This means you have your documentation ready to hand and archived in a searchable format at all times.

Not every device is tested in the same way. A decisive factor is the protection class of the equipment. The electrician must classify the device correctly before measuring it.

• Protection class I (with protective conductor): Here, the protective conductor resistance is the most important measured variable (usually devices with a protective contact plug).
• Protection class II (protective insulation): These devices do not have a protective conductor, but are double insulated (recognizable by the narrow contour plug). Here, the focus is on the insulation resistance.
• Protection class III (safety extra-low voltage): These devices operate at a safe voltage, but must be checked to ensure they are correctly isolated from the mains.