Samson 4747, Mounting And Operating Instructions

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34 EB 4747 EN
Electrical connections
− For Ex db T6 only use cables and ca -
ble glands which are suitable for the
temperature range from –55 to
+80 °C.
− For Ex db T5 only use cables and ca -
ble glands which are suitable for the
temperature range from –55 to
+95 °C.
− For Ex db T4 only use cables and ca -
ble glands which are suitable for the
temperature range from –55 to
+100 °C.
Î
Include the enclosure of the limit switch in
the on-site equipotential bonding system.
Use the external grounding connection
on the enclosure.
6.2 Electrical connection for
type of protection Ex ia
Incorrect electrical connection will render
the explosion protection unsafe.
Adhere to the terminal assignment.
Do not undo the enameled screws in or on
the enclosure.
Do not exceed the maximum permissible val-
ues specified in the EU type examination cer-
tificates when interconnecting intrinsically
safe electrical equipment (U
i
or U
0
, l
i
or I
0
, P
i
or P
0
, C
i
or C
0
and L
i
or L
0
).
Observe clause 12 of EN 60079-14: 2008
(VDE 0165, Part 1) for installation of the in
-
trinsically safe circuits.
WARNING !
Clause 12.2.2.7 applies when running multi-
core cables and wires with more than one
intrinsically safe circuit.
The radial thickness of the insulation of a
conductor for common insulating materials
(e.g. polyethylene) must not be smaller than
0.2 mm. The diameter of an individual wire
in a fine-stranded conductor must not be
smaller than 0.1 mm. Protect the conductor
ends against splicing, e.g. by using wire-end
ferrules. Fit equipment used in ambient tem-
peratures below –20 °C with metal cable
glands.
6.3 Equipment with type of
protection Ex t
Opening the limit switch in potentially
explosive dust atmospheres will render the
explosion protection unsafe.
Do not open the enclosure cover of the limit
switch in potentially explosive dust atmo-
spheres.
In equipment operated according to type of
protection Ex t (protection by enclosure), cir -
cuits may be connected, interrupted or
switched while energized only during instal -
lation, maintenance or repair.
Î
Use certified cable glands and blanking
plugs with appropriate type of protection
with an IP rating ≥ 66 and suitable for
the certified temperature range.
DANGER !