MEDC dGW 21 - Manual (Page 3)

Application
The signalling bell dGW21 was
designed to warn, call and signal in
areas with explosive atmospheres
and rough ambient conditions. The
explosion categories Ex d e IIC T6 Gb
and Ex tb IIIC T80°C Db allows the
signalling bell to be used in areas
with explosive atmospheres in zone
1 and 2 and in zone 21 and 22.
The signalling bell produces a
sound volume of approx. 105 dB(A)
at 1 meter distance.
The emphasis of the ring lies at
approx. 1000 Hz, as a result of
which the signal stands out clearly
against lower-frequency ambient
noises. The bell is available for all
usual supply voltages. The version
dRGW 21 comprises a telephone
calling relay and reproduces the
signals in the pulse rate of the
overriding telephone call.
Design
Explosion protection is ensured by
the flameproof enclosure of the
driver system and the terminal box
realised in the explo sion protection
mode “in creased safety”. The
flame proof room contains the elec-
tromagnetic driver system and, for
the design dRGW21 an additional
telephone calling relay. The enclo-
sure is made completely of plastic
thus guaranteeing protection from
corrosion. In addition we realize
insulation class II, so there is no
equipotential bon ding necessary.
The construction is furthermore
low-weight and very robust. All d.c.
versions are equipped with an
electronic contact breaker which
considerably increases service life
compared with other available
devices.
Recycling
The device can be disposed of
completely as electronic waste.
When the device is disassembled,
plastics, metals and electronics are
to be disposed of separately.
Assembly
The signalling bell is suitable for eit-
her wall or ceiling mounting. Please
refer to page 5 for mounting
dimensions. All fixing elements and
bases must bear the weight of the
device (approx. 3.5 kg). Please
assemble the wall fixtures, which
are part of the scope of delivery,
(including assembly material) and
arrester plate according to Figure 1
on page 5. Make sure the catches
of the safety plate fit in the ope-
nings in the wall bracket.
Connecting and adjusting
The device may only be connected
and adjusted by qualified personnel.
The regulations and instructions of
the respective country regarding
connection to the public telephone
network and/or to private branch
exchanges (PBX) have to be con -
sidered. The following regulations
concerning connection and adjust-
ment
are to be observed.
Regulations regarding connection
to the mains must also be obser-
ved. Mains connection at terminals
1 and 4. Connection to other
devices at terminals 2 and 3 (see
Fig. 2 on page 5). When using the
telephone calling relay connect
mains to terminals 1 and 2 and the
telephone connection to terminals
3 and 4 (see Fig. 3 on page 5).
Remarks
Each signalling bell is adjusted in
the works. Should the sound alter
after a certain number of operating
hours, a qualified person can adjust
the tappet in the device as follows:
• Apply rated voltage
• Push the bell system higher after
unscrewing the system fixing
screws until the sound is optimal
• Replace the system fixing screws
and tighten
These adjustments may be carried
out only outside of the hazardous
area.
Warning:
The device has a very loud sound
volume. To avoid damage to the
hearing, do not come too close to
the sound emitter.
3
Technical specification
Enclosure Fiberglass reinforced polyester
Colour of enclosure Black or red
Insulation class II (no potential bonding necessary).
Protection category IP 66 (acc. IEC 529/EN 60529)
Cable glands 1x M20 x 1.5 and vent plugs M20 x 1.5
optionally 2x cable entry M20 x 1.5 for design dRGW21
Operating temperature -20°C bis +40°C
Storage temperature -20°C bis +80°C
Operating mode Continuous operation as per IEC34; DIN EN 60034-1; VDE 0530 Level S1
Operating utilization position Bell dome to the front (tappet downwards)
Operating conditions Inside or outside
Connecting terminals 1.5 mm 2 stranded wire
2.5 mm 2 solid wire
Sound pressure level approx.105 dB(A) at 1 meter distance
Explosion category Ex d e IIC T6 Gb
Ex tb IIIC T80°C Db (only black housing)
EC-type-examination certificate PTB 01 ATEX 1064
Dimensions Approx. 210 x 190 x 190 mm
Weight Approx. 5.5 kg
Warning! At the devices there is hazard of ignition by electrostatic discharges. Charging e.g. by friction or
during cleaning has to be avoided. The assembly has to be carried out in a way that a hazardous electro-static
charging e.g. by pneumatic delivery will be avoided.