Introduction; Installation; Wiring Options - MEDC DB1 Manuel Technique

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
operation 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
TECHNICAL MANUAL FOR THE SOUNDERS – DB1 & DB1H TM153 Issue I August 2019 www.eaton.com
Technical Manual for the Sounders – DB1 & DB1H
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.
Once termination is complete ensure that both the spigot
of the cover and the mating face of the body are well
covered with a suitable anti-seize compound. Carefully
lower the cover assembly back onto the base, avoiding
damage to the mating surfaces, ensuring the O-ring is
correctly seated in its groove during re-assembly. Replace
the 4 off M6 screws (5.0mm A/F hexagon key) into the
holes in the cover assembly and tighten evenly. Ensure
the required gap (0.2mm Max.) is maintained between
the cover and the base.

Wiring options

The unit is available in three basic configurations:
1. DC input, single tone
2. DC input, dual tone
3. AC input, single tone
Type 1 has 8 terminals labelled as TB1 to TB8. The supply
should be connected to TB1 (+ve), TB3 (-ve), loop out on
TB2 & TB4 respectively.
Type 2 has 8 terminals labelled as TB1 to TB8.
For a 2 wire system, the supply should be connected to
TB1 (+ve), TB3 (-ve), loop out on TB2 & TB4 respectively
to produce tone 1. Tone 2 is produced when the polarity
of the supply is reversed TB1 (-ve), TB3 (+ve), loop out on
TB2 & TB4 respectively. Optionally, an EOL resistor may
be fitted between TB2 & TB4.
For a 3 wire system, the supply should be connected to
TB1 (common +ve), TB3 (-ve1) & TB5 (-ve2), loop out on
TB2, TB4 & TB6 respectively. Tone 1 is produced when the
supply is connected to TB1 (common +ve) & TB3 (-ve1).
Tone 2 is produced when the supply is connected to TB1
(common +ve) & TB5 (-ve2). Alternatively Tone 2 may also
be produced by reversing the polarity of the Tone 1 supply
TB1 (-ve), TB3 (+ve), loop out on TB2 & TB4 respectively.
Optionally and EOL resistor can be fitted between TB2 &
TB4 or TB2 & TB6.
Type 3 has 8 terminals labelled as TB1 to TB8. The supply
should be connected to TB1 (Live), TB3 (Neutral), loop out
on TB2 & TB4 respectively.
English
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