The possibility of a blackout can no longer be ruled out. Due to the increasing number and importance of electronic devices and tools, the consequences of a total power outage are also significantly more drastic. An emergency power supply is thus indispensable to command centers of emergency and disaster relief organizations, in particular. There are crucial details to consider.

What is the method for feeding power?

The necessary building infrastructure is required (mains isolator and feed interface). Theoretically, a building could be powered with any power generator of the corresponding power class, but beware:

Power generators for fire departments (DIN 14685, DIN 14686, DIN 14687) are designed with safety isolation. This system is undoubtedly one of the safest. But it works differently than residential grids, which can lead to various negative effects when supplied by such generator systems. Depending on the design of the building installation and the selected option on the emergency generator system, error messages on the generator (insulation fault), disconnection of the generator system, and/or suspension of the earth leakage within the building may occur.

The solution

The new option for supplying buildings offers the following solution. By means of an additional toggle switch, the generator network configuration is switched from safety isolation (operating mode 1) to TN network (operating mode 2 – feed-in mode) so that the RCD in the building remains functional and isolation faults do not occur at the generator. To prevent operating errors, a socket with special coding (1 o’clock) is installed on the rear of the power generator. A normal consumer may not and cannot be plugged into this socket; it is designed exclusively for the building feed. A 1 o’clock socket should also be installed at the interface on the building.

 What does this require?

The power generator must be equipped with the described infeed function as well as with the necessary socket including 1 o’clock coding. And of course a specialist electrical engineering company must also check the suitability of the building’s infrastructure.

The necessary connecting cable is also clearly defined and has appropriate adapters for connecting to different connector sizes. The size of the cable depends on the building and must, therefore, be provided by the building’s owner.

To make power generators and home appliances compatible, the new standard DIN 14684 (generators with feed-in function) provides clear specifications for the responsible electrical companies.


Rosenbauer power generatorsThe new feed-in function on the RS14 power generator makes using a firefighting power generator as a source of energy for a building very convenient and easy. It not only saves time in situations where every minute counts, but also provides certainty that, in the event of an incident, all safety devices in the building will function and that the generator system will not detect any insulation faults due to the connected building installation.

Recommendation: Do not skimp on safety! At least one power generator with an additional function for supplying buildings should be part of the basic equipment of every fire department – of course, proper building infrastructure is also required.