E2S STExB2X05 Series Instruction Manual page 4

7.2. Cable Selection and Connections
When selecting the cable size, consideration must be given to
the input current that each unit draws (see table 1), the number
of beacons on the line and the length of the cable runs. The
cable size selected must have the necessary capacity to
provide the input current to all of the beacons connected to the
line.
Electrical connections are to be made into the terminal blocks
on the PCBA, using solid wire 0.5-4mm2 / AWG 20-12 or
stranded wire, sizes 0.5-2.5mm2 / AWG 24-14. Wire insulation
needs to be stripped 8mm. Wires may be fitted securely with
crimped ferrules.
Figure 4: Wire Preparation.
Terminal screws need to be tightened down with a tightening
torque of 0.45 Nm / 5 Lb-in.
See section 9.1 for terminal positions.
Figure 5: STExB2 Entries and Earth 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
Please note that for AC supply voltage product versions the
Earth terminal on the PCBA does not provide an earth
connection to the product enclosure. The enclosure must be
independently earthed using either the external or internal
earth fixing point, (see fig 9 and notes below).
Internal earthing connections should be made to the Internal
Earth terminal in the base of the housing using a ring crimp
terminal to secure the earth conductor under the earth clamp.
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. The external earth conductor should be at
least 4mm2 in size.
E2S Warning Signals Impress House, Mansell Road, Acton, London W3 7QH
Document No. D199-00-581-IS Issue 1 07-11-23
7.3. Cable Glands, Blanking Elements & Adapters
Follow the minimum temperature ratings of cables and cable
glands according to the approvals applied.
For high ambient temperatures the cable entry temperature
may exceed 70ºC or the cable branching point temperature
may exceed 80ºC and therefore suitable heat resisting cables
and cable glands must be used, with a rated service
temperature at least as stated below:
Table 2: Min. Ratings of Cables &
Cable Glands.
Cable Glands & Blanking Plugs
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.
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.
Any unused cable entries must be closed with suitably rated
and ATEX / IECEx & UKEx certified blanking plugs.
Ingress Protection
Follow instructions according to the approvals applied.
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.
For combustible dust applications, the cable entry device and
blanking elements shall be in type of explosion protection and
shall have an IP 6X rating.
Adapters
The STEx Beacon Range can be supplied with the following
types of adapters:
M20 to 1/2" NPT
M20 to 3/4" 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 certified
adapters.
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