Samson 3730-4, Mounting And Operating Instructions

Page: 50 / 212

3.2 Electrical connections
The following standards apply to in-
stallations in hazardous areas:
EN 60079-14: 2008 (VDE 0165
Part 1)
Explosive atmospheres -
Electrical installations design, selec-
tion and erection
.
NOTICE
– The terminal assignment must be ad-
hered to. Reversing the assignment of the
electrical terminals may cause the explo-
sion protection to become ineffective!
– Do not loosen enameled screws in or on
the housing.
– For the interconnection of intrinsically
safe electrical equipment, the permissible
maximum values specified in the EC type
examination certificate apply (U
i
or U
o
,
I
i
or I
o
, P
i
or P
o
, C
i
or C
o
and L
i
or L
o
).
Note on the selection of cables and wires:
To install intrinsically safe circuits, observe
Clause 12 of EN 60079-14: 2008
(VDE 0165 Part 1).
To run multi-core cables or lines with more
than one intrinsically safe circuit, clause
12.2.2.7 of this standard applies.
Especially for commonly used insulating ma-
terials, such as polyethylene, the radial
thickness of the conductor insulation must
have a minimum thickness of 0.2 mm. The
diameter of a single wire of a flexible con-
ductor must not be smaller than 0.1 mm.
Protect the conductor ends against splicing,
e.g. by using wire-end ferrules.
When two separate cables are used for con-
nection, an additional cable gland can be
installed.
Seal cable entries left unused with blanking
plugs.
Devices used at ambient temperatures be-
low –20 °C must be fitted with metal cable
glands.
Equipment for use in zone 2/zone 22
In equipment operated with type of protec-
tion Ex nA II (non-sparking apparatus), the
standard EN 60079-15: 2003 specifies that
circuits may be connected, interrupted or
switched while energized only during instal-
lation, maintenance or repair.
For equipment connected to energy-limited
circuits with type of protection Ex nL (en-
ergy-limited apparatus), the standard
EN 60079-15: 2003 allows this type of
equipment to be switched under normal op-
erating conditions.
For the interconnection of equipment to en-
ergy-limited circuits with type of protection
Ex nL IIC, the permissible maximum values
specified in the statement of conformity
apply.
Cable entry
The cable entry with M20 x 1.5 cable gland,
6 to 12 mm clamping range.
There is a second M20 x 1.5 threaded bore
in the housing that can be used for addi-
tional connection, when required.
The screw terminals are designed for wire
cross-sections of 0.2 to 2.5 mm² (tightening
torque of screws 0.5 to 0.6 Nm).
50
EB 8384-4 EN
Connections