Innovative EV21 Voice sounder solution increases staff safety at BMW
Eaton installs sounder as an evacuation alarm in factories and offices across 9 sites

The BMW Group was established in 1916 as “Bayerische Flugzeugwerke AG” and, with around 125,000 employees, it is now one of the largest automobile manufacturers in the world. The BMW Group incorporates the brands BMW, MINI and Rolls-Royce. In addition, BMW manufactures motorcycles and offers premium financial and mobility services. In the event of an emergency or explosion risk, BMW must warn its employees in time and evacuate them from the hazardous areas in an orderly manner. Specialized sounders that provide an acoustic alarm are required for this purpose.

The Munich automobile manufacturer BMW places top priority on the safety of its employees. In 2005, the company therefore decided to install alarm systems at all its sites for evacuating the production floors, in order to bring employees safely out of the building in the event of danger such as fire or potential risks of explosion, either from gases or vapours in the air.

BMW decided to use a motor siren as a standard sound for the evacuation alarm. The alarm sound for evacuating the production locations must be identical at all factories in the German-speaking region.

Specifically, these are the sites in Munich, Dingolfing, Berlin, Landshut, Regensburg, Wackersdorf, Leipzig, Steyr and Graz. “The relevant sounder must be highly available and run smoothly”, explained Gerhard Daum from the BMW Group Architecture and Building Projects Department. He is responsible for the planning preparations as well as the basic structural and technical facilities.

In 2008, Eaton developed the EV21B sounder as a one-off for the factory floors. BMW currently has approximately 900 of these robust devices, which use the sound of a motor siren – the sound sequence is stored on a memory chip as an MP3 file. The EV21B sounders are installed at a height of eight metres in the industrial halls, but their sound and volume have little variation.

“The motor sirens’ non-adjustable volume of 110 dB is hugely problematic if you want to use the sounder in small, separate workshops or offices”, explained Gerhard Daum. When all of BMW’s attempts at turning down the volume themselves failed, the company asked Eaton to develop a new sounder for the offices and workshops at all of its factories in the German-speaking region.

The requirements were clear: the new sounder should have the same sound of a motor siren in order to ensure the safety of employees during evacuations. The volume also had to be infinitely adjustable in order to suit the installation location.

Eaton therefore developed the EV21 Voice sounder for BMW, a more advanced version of the EV21B. At the request of BMW, Eaton used the same housing but improved the electronics. The power consumption is also lower. The device consists of plastic-coated, seawater-resistant aluminium casting. The loudspeaker is made of an impact-resistant and cold-resistant synthetic material and is installed as a fixed component in the housing. The operating temperature of -25°C to +60°C and the robust design make it suitable for use even in harsh environmental conditions.

The EV21 Voice generates the BMW siren tone digitally; it is played when a supply voltage of 230 VAC is applied. The device comes pre-programmed upon delivery. The siren sound is stored as a WAV file on the device’s 2 GB internal micro SD card. The memory card also includes installation software with operating instructions customers can install on their PC.

BMW can thus create additional WAV files with signals for other purposes and play them back on the micro SD card. The software also allows programmable sound files that can include both voice messages as well as signal tones in one composition.

BMW currently uses around 1,600 EV21 Voice sounders in the offices and separate, smaller workshops at the factories in the company’s German-speaking locations. “The volume of the EV21 Voice can be flexibly regulated from 0 to 110 dB and each device can be individually controlled. This allows us to also use the EV21 Voice in offices or the smaller, separate workshops at our factories, thereby ensuring the safety of all employees if the evacuation alarm is sounded”, said Gerhard Daum.