Special Conditions For Safe Use; Functional Safety - MEDC DB3 Manuel Technique

6.0 SPECIAL CONDITIONS FOR SAFE USE

a) Type DB3/DB3L - IECEx BAS 11.0083X & BAS00ATEX2097X (Exd)
1. This apparatus is not suitable for use in atmospheres containing carbon disulphide
2. This apparatus is suitable for use only in ambient temperatures as follows:
Max. Power
Type
rating
15W
DB3
15W
15W
DB3L
15W
3. Painting and surface finishes, other than those applied by the manufacturer, are not permitted
4. When used in dust atmospheres the flameproof cable entry devices or stopping plugs shall be selected and
installed to maintain the dust tight (IP6X) integrity of the enclosure
b) Type DB3E/DB3LE - IECEx BAS 11.0084X & BAS00ATEX2098X (Exe)
1. This apparatus is not suitable for use in atmospheres containing carbon disulphide.
2. Not more than one single or multiple strand wiring lead shall be connected into either side of any terminal,
unless multiple conductors have been joined in a suitable manner, e.g. two conductors into a single
insulated boot lace ferrule.
3. Leads connected to the terminals shall be insulated for at least 275V and this insulation shall extend to
within 1mm of the metal of the terminal throat.
4. All terminal screws, used and unused, shall be fully tightened down.
5. This apparatus is suitable for use only in ambient temperatures as follows:
Max. Power
Type
DB3E
DB3LE
6. Minimum creepage and clearance distances between the terminals and adjacent conductive parts
(including cable entry devices) must be at least 5mm.
7. Painting and surface finishes, other than those applied by the manufacturer, are not permitted.
8. When used in dust atmospheres the flameproof cable entry devices or stopping plugs shall be selected and
installed to maintain the dust tight (IP6X) integrity of the enclosure.

7.0 FUNCTIONAL SAFETY

Introduction
The DB3 sounder has been designed for use in potentially explosive atmospheres and harsh environmental
conditions. The glass reinforced polyester enclosures are suitable for use offshore or onshore, where light weight
combined with corrosion resistance is required.
The DB3 sounder can be configured with or without an Exe Chamber on the rear. The FMEDA has considered the
worst case scenario which includes the Exe Chamber on the rear.
The safety function of the sounder is to provide a pre-determined audible warning sound when required if the
correct voltage is applied to the unit. The DC version of the sounder is designed to operate on a supply voltage
between 12 and 48vDC; the AC versions of the sounder are designed to operate on a supply voltage tolerance of
+/- 10%.
Under No fault (Normal) Operating conditions the DB3 sounder will provide an audible warning sound when
required by the system.
Under fault conditions the failure mode of the sounder is a failure to provide an audible warning sound. For the
failure rate associated with this failure mode please refer to the table below.
07/14
T
amb.
-20°C to +55°C
-20°C to +70°C
-55°C to +55°C
-55°C to +70°C
T
rating amb.
15W -20°C to +55°C
15W -20°C to +70°C
15W -50°C to +55°C
15W -50°C to +70°C
T T
G D
T5
T100°C
T4
T135°C
T5
T100°C
T4
T135°C
T T
G D
T5
T100°C
T4
T135°C
T5
T100°C
T4
T135°C
© MEDC 2014