Siemens SIMATIC TIM 3V-IE DNP3, System Manual

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Accessories
A.5 LTOP overvoltage protection modules
TIM DNP3
System Manual, 12/2015, C79000-G8976-C253-04
327
A.5 LTOP overvoltage protection modules
A.5.1 Variants and overview of the LTOP overvoltage protection modules
Copper dedicated lines are highly susceptible to electromagnetic interference. The coupling
of extraneous voltages can be inductive or capacitive, for example due to the effects of
lightning. Direct conductive coupling is also possible due to bad insulation.
The LTOP overvoltage protection modules limit extraneous voltage and overvoltage to a
non-critical level. The floating transformer also provides electrical isolation preventing
coupling of voltages into other cable sections. An LTOP protects persons and investment
and is therefore an indispensable safety element in private dedicated line networks.
Image A-11 LTOP2 overvoltage protection module
The LTOP overvoltage protection module is available in two variants:
LTOP 1
Overvoltage protection module for use at the start or end of a 2-wire dedicated line.
LTOP2
Overvoltage protection module for use at the start or end of a 4-wire dedicated line or in a 2-
wire tapping point. In a 4-wire tapping point, two LTOP2 modules are required.
Table A- 3 Overview of the LTOP modules
Short name Order no. Explanation
LTOP1 6NH9821-0BC11 Single line transformer LTOP1, with one OPM over-
voltage protection module for use at the start or end
of a 2-wire dedicated line
LTOP2 6NH9821-0BC12 Double line Transformer LTOP2, with two OPM
overvoltage protection modules for use at the start or
end of a 4-wire dedicated line or a 2-wire tapping
point
OPM 6NH9821-0BB00 OPM overvoltage protection module for LTOP1 and
LTOP2, plug-in (pack of 4)
The two LTOP variants have both screw terminals and an RJ-12 Western jack.