MEDC DB20C - Manual (Page 3)

© MEDC 2013 11/13
English
1.0 INTRODUCTION
This range of loudspeakers, intended for use in potentially explosive atmospheres, has a power rating
of up to 8W.
The unit is available in a number of versions suitable for use in the following gas/dust groups.
IIB GAS GROUP UNIT - Ex de IIB T3 (Tamb -50°C TO +70°C)
IIC GAS GROUP & DUST UNIT - Ex de IIC tD A21 T130°C (Tamb -50°C TO +70°C) IP65
The body and cover are manufactured completely from a UV stable glass reinforced polyester. The
outer flare is manufactured from ABS. Stainless steel screws and mounting bracket are incorporated
thus ensuring a corrosion free product.
A ceiling mount version (DB20C) is available which provides a patended, self-supporting and self-
locking mounting suitable for ceiling tiles from 0.5 to 55mm thick. The speaker is held in the mount via
a twist-fit support and locking grille, giving access from above or below.
2.0 GENERAL SAFETY MESSAGES AND WARNINGS
All instructions and safety messages in this manual must be followed to allow safe installation of the
device. The device must only be installed and maintained by correctly trained site personnel/installers.
i. To reduce the risk of ignition of hazardous atmospheres and shock, do not apply power to the
device until installation has been completed and the device is fully sealed and secured.
ii. To reduce the risk of ignition of hazardous atmospheres and shock, keep device tightly closed
when the circuit is energised.
iii. Before removing the cover for installation or maintenance, ensure that the power to the device is isolated.
iv. Following installation, test the device to ensure correct operation.
v. Following installation ensure a copy of this manual is made available to all operating personnel
vi. When installing the device, 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 also apply.
vii. Cable termination should be in accordance with specification applying to the required application.
MEDC recommends that all cables and cores should be correctly identified. Please refer to the
wiring diagram in this manual (or separate diagram provided with the unit).
viii. Ensure that only the correct listed or certified cable glands are used and that the assembly is
shrouded and correctly earthed.
ix. 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.
x. MEDC recommend the use of a sealing compound such as HYLOMAR PL32 on the threads of all
glands and stopping plugs in order to maintain the IP rating of the unit.
xi. A suitable sealing washer must be fitted to all glands and stopping plugs fitted into the enclosure.
xii. The internal earth terminal, where fitted, must be used for the equipment grounding and the
external terminal, if available, is for a supplementary bonding connection where local codes or
authorities permit or require such a connection.
xiii. When installing the device, MEDC recommends the use of stainless steel fasteners. Ensure that all
nuts, bolts and fixings are secure.
xiv. The unit should be positioned such that debris, dust or water cannot settle in the re-entrant horn.