European Safety Systems Ltd.
Impress House, Mansell Road, Acton, London W3 7QH
www.e2s.com
Tel: +44 (0)208 743 8880
Document No. D157-00-651-IS
Issue 2
06-03-2023
Sheet 4 of 14
Figure 5: GNExS1 Entries and Terminal Block Location.
When connecting wires to the terminals great care should be
taken to dress the wires so that when the cover is inserted into
the chamber the wires do not exert excess pressure on the
terminal blocks. This is particularly important when using
cables with large cross-sectional areas such as 2.5mm².
Earthing
Both AC and DC sounder units must be connected to an earth
according to EN/IEC 60079/14. The units are provided with
internal and external earth terminals which are both located on
the terminal chamber section of the unit (see figure 5).
Internal earthing connections should be made to the PCB
terminal block or to the Internal Earth Stud of the housing using
a ring crimp terminal to secure the earth conductor between
the two M4 stainless steel flat washers. The earth conductor
should be at least equal in size and rating to the incoming
power conductors.
External earthing connections should be made to the M5 earth
stud, using a ring crimp terminal to secure the earth conductor
to the earth stud between the two M5 stainless steel flat
washers, then reassemble the M5 spring washer and tighten
the M5 nut to ensure that the cable lug is secured against
loosening and twisting. The external earth conductor should be
at least 4mm
2
in size.
7.3. Cable Glands, Blanking Elements & Adapters
For high ambient temperatures the cable entry or the cable
branching point temperatures may exceed:
•
70ºC at entry point.
•
80ºC at branching point.
Therefore, suitable heat resisting cables and cable glands
must be used, with a rated service temperature at least as
stated in the table below:
Max Ambient Temperature (ºC)
Model
40
45
50
55
60
65
70
GNExS1[F/R]
DC024-S
70
75
80
85
90
95
Table 2: Min. Ratings of Cables & Cable Glands.
Cable Glands
Appropriate cable glands to be customer supplied.
The cable entries have an M20 x 1.5
–
6H entry thread. Only
suitably rated and ATEX / IECEx & UKEx certified cable glands
must be used. They must be suitable for the type of cable being
used and also meet the requirements of the current installation
standards EN 60079-14 / IEC60079-14.
Blanking Plugs
When only one cable entry is used the other entries must be
closed with suitably rated and certified blanking plugs as per
type of approval.
Any unused cable entries must be closed with suitably rated
and ATEX / IECEx & UKEx certified blanking plugs.
Ingress Protection
If a high IP (Ingress Protection) rating is required, then a
suitable sealing washer must be fitted under the cable glands
or blanking plugs. A minimum ingress protection rating of IP6X
must be maintained for installations in explosive dust
atmospheres.
Adapters
The GNEx sounder range can be supplied with the following
types of adapters:
M20 to ½” NPT
M20 to ¾” NPT
M20 to M25
It is important to note that stopping plugs cannot be fitted onto
adapters, only directly onto the M20 entries.
Any other adapters used must be suitably rated and ATEX /
IECEx & UKEx certified adapters.
If the installation is made using conduit, openings must have a
sealing fitting connected as close as practical to the wall of the
enclosure, but in no case more than the size of the conduit or
50mm, whichever is the lesser.
