DGUV 3 (BGV A3) and testing of fixed installations as process solution:

Permanent repeat test without shutdown. 


Managers and technical managers of data centers are constantly faced with the challenge of ensuring high power supply availability. Even short interruptions in the millisecond range can have serious and far-reaching consequences. An essential aspect of this is not only the protection via appropriate UPS systems, but also the proper construction of the network structure and the exclusive use of TN-S systems according to VDE 0100-444.  


Furthermore, it is important to maintain this orderly state of the new installation in the long term, because an unintentional bridge between N and PE conductor can cause inexplicable disturbances.



Similarly problematic can be the exposure of the network to harmonics by modern consumers. Overloaded N conductors and the associated fire hazards or EMC interference are not unknown variables. Preventive monitoring must also be used to prevent the activation of protective devices due to excessively high residual currents.

Residual current monitoring (RCM) is playing an increasingly important role in applications requiring highly available power supplies.

Applications can be found in almost all market segments. In particular, continuous processes and particularly sensitive applications such as data centers, hospitals or semiconductor factories rely on RCM monitoring. RCM measurement is a good alternative wherever insulation resistance measurements and residual current circuit breakers cannot be realized due to local or operational conditions.

Stationary electrical installations and equipment must be regularly tested in accordance with the accident prevention regulation DGUV regulation 3 (BGV A3) in order to ensure the necessary electrical safety and high availability. However, insulation measurement is no longer possible today, or can only be carried out at enormous technical and economic expense.


Detailed knowledge of the DGUV 3 regulation should be a matter of course for a qualified electrician (EFK). After all, it is the source specification for the SFAO concept. It should be noted, however, by the way, that the accident prevention regulations under §15 SGB VII constitute autonomous law of the statutory accident insurance and are therefore binding for the company (computer centre, production plant, etc.). A decisive aspect with the assumption of responsibility as VEFK is the associated personal liability (see also Nöthlichs, M. u. a.; Arbeitsschutz und Arbeitssicherheit, 3rd Edition, Berlin, Erich Schmidt Verlag 2008).

Repeat testing can only be dispensed with under certain conditions. This exception applies only to stationary electrical installations and equipment. It must be ensured that the ongoing maintenance work, together with the measurements required by the operator, reveals defects similar to repeat tests.

Using our BGVA3 Cloud application with the CPI process chain for continuous repeat testing, a declaration of conformity issued by the Employer's Liability Insurance Association, we have created a monitoring system for uninterrupted fault current monitoring that meets all requirements of the Employer's Liability Insurance Association and the VDS. The corresponding reports regarding the safety of the measured electrical system are automatically made available to you on a weekly and monthly basis for your documentation. Possible insulation fault alarms are sent to you immediately and the CPI process chain for the professional elimination of the fault is started.

Our DGUV regulation 3 (BGV A3) offers the following advantages: Continuous repeat testing by means of


RCM measurement technology:

  • No shutdown of your system (server, IT technology, production machines, machine tools, etc.)
  • Higher operational reliability through early detection of possible critical plant conditions
  • Higher productivity
  • Significant reduction of operating costs
  • Time- and cost-optimized maintenance
  • Production interruptions are prevented
  • Monitoring highly available energy distributions
  • Early warning of system errors
  • Localization of single faulty outlets, less effort for troubleshooting
  • Overloads of the N-conductors and critical residual currents are detected at an early stage, thus increasing fire safety.
  • Fulfilment of the security criterion "RCM fault current monitoring" in the data center
  • Limit value overstepping of unbalanced currents


Prerequisite for the RCM measurement is a TN-S network. In accordance with EN 50600-2-2:2014 and DIN VDE 0100 444:2010-10, TN-S systems are nowadays the norm for the use of IT technology and system-end measurement and control systems.


Before the control operation begins, all installed differential current measuring devices are tested by means of a standard-compliant device (in accordance with DIN EN 61557-11 VDE 0413-11:2009-11: Electrical safety in low-voltage networks up to AC 1 000 V and DC 1 500 V - devices for testing, measuring or monitoring protective measures: The effectiveness of residual current monitoring devices (RCMs) type A and type B in TT, TN and IT systems) of the test device is checked for proper installation and function by our electrical specialist team.


For older systems (TN-C, TN-CS) it is necessary to upgrade the system to a TN-S system (fire hazard, protection of material assets, protection of persons etc.). Today, this requirement is a key function for the safety and economic success of the company in many industries and application areas.


Our cloud system is ideally suited for capturing the energy data of a large number of consumers with minimal effort and transferring it to our cloud databases.

Irrespective of future legal requirements and existing possibilities for a favourable energy supply, energy optimization and saving always offer a high economic savings potential.

ISO 50001 describes energy recording as a prerequisite for energy management systems. The greater the information density, the better the savings potential can be determined.

With our energy data acquisition and differential current monitoring system, disturbances in the power supply can be avoided by early warning. Furthermore, plant and fire protection are increased.


Our Cloud Automation solution is 100% compliant with the BSI 100:2013 standard, validated by E&Y in a penetration test and installed in a TÜV Level 2+ certified data center in NRW/Germany (Backup Data Center/Dual Site Data Center). 


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