The signalling bell dGW21 was designed to warn, call and signal in group II explosive atmospheres and rough environmental conditions in hazardous
areas. The signalling bell produces a sound volume of approx. 105dB(A) at 1 meter distance.
The frequency of the sound of the bell is approx 1kHz, meaning the signal can be clearly heard against lower frequency background noise. The bell
can also be activated with the presence of a telephone ringing signal in the dRGW 21 version.
The protection of this product is a mixture of Exd “flameproof” for the driver system and Exe “increased safety” for the termination chamber. The dRGW
21 offers initiation by a relay from a telephone ringing voltage. The flameproof chamber contains the electromagnetic driver system and the enclosure is
made from GRP (glass-fibre reinforced polyester), guaranteeing protection against corrosion. As the dGW 21 is safety class II, so there is no
equipotential bonding necessary.
All D.C. versions are also equipped with an electronic contact breaker, increasing product service life.