MEDC DB1 Manuel Technique page 3

English
1.0 INTRODUCTION
This range of light weight, flameproof sounders has been designed with a high weatherproof rating to cope with
the harsh environmental conditions found offshore and onshore in the oil, gas and petrochemical industries
New electronic circuitry allows the DB1 and DB1H to be switched between two user selectable tones by either
reversing the polarity, or connecting a second voltage supply (dual tone facility is available on dc units only).
The higher output DB1H is particularly suitable for noisy environments.
2.0 INSTALLATION
General
When installing and operating explosion-protected equipment, requirements for selection, installation and op-
eration should be referred to e.g. IEE Wiring Regulations and the 'National Electrical Code' in North America.
Additional national and/or local requirements may apply.
Ensure that all nuts, bolts and fixings are secure.
Ensure that only the correct listed or certified stopping plugs are used to blank off unused gland entry points
and that the NEMA/IP rating of the unit is maintained. MEDC recommend the use of a sealing compound such
as 'HYLOMAR PL32' on the threads of glands and stopping plugs in order to maintain the IP or NEMA rating
of the unit.
The sounder is mounted via the 2 off Ø9mm fixing holes. The fixing holes have been designed to accept an M8
screw or bolt.
MEDC recommend the use of stainless steel screws.
The unit has been designed and certified to operate at any attitude – from horizontal to vertical however, it is
important to note that the alignment of the sounder should ensure that:-
1. Dust or debris cannot lodge or settle in the re-entrant horn
2. Water from hoses, jets or rain cannot settle in the re-entrant horn
Cable Termination
CAUTION: Before removing the cover assembly, ensure that the power to the unit is isolated.
Unscrew the 4 off M6 screws (5.0mm A/F hexagon key) holding the cover assembly to the base. Keep screws
in a safe accessible place as they are not retained in the cover.
Before lifting the cover, gently twist the cover assembly clockwise then anti-clockwise to break the seal.
Continue to gently twist the cover clockwise and anti-clockwise while gently lifting the cover assembly away from
the base of the enclosure to gain access to the interior.
The cover assembly is connected to the cover by a nylon restraining strap to prevent loss.
Cable termination should be in accordance with specifications applying to the required application. MEDC
recommends that all cables and cores should be correctly identified. Please refer to the wiring diagram provided
with the product and see below for wiring options.
Ensure that only the correct listed or certified cable glands are used and that the assembly is shrouded and
correctly earthed.
All cable glands should be of an equivalent NEMA/IP rating to that of the unit and integrated with the unit such
that this rating is maintained.
The internal earth terminal, where fitted, must be used for the equipment grounding connection and the external
terminal is for a supplementary bonding connection where local codes or authorities permit or require such a
connection.
© Eaton MEDC Ltd 2018 01/18