g. The neutral conductor (N)
is connected the protective earth via collective
spark gap.2. With the 3+1 circuit, the external
conductors (L1, L2, L3) are connected the neutral
conductor (N) via arrestors.3. V20-3+NPE).4: Rated surge voltage for equipment accordance with installation standard IEC 60664
TBS
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189
Chapter The internal lightning protection system
.
Nominal voltage of
power supply system (1)
(mains) according to
IEC 60038 (3)
Voltage between phase and neutral
wire derived from the nominal AC
or nominal voltage and
including
v
Rated surge voltage (2)
v
Surge voltage category (4)
Three-phase Single-phase III IV
120/240
50 330 500 800 1500
100 500 800 1500 2500
150 800 1500 2500 4000
230/400, 277/480 300 1500 2500 4000 6000
400/690 600 2500 4000 6000 8000
1000 1000 4000 6000 8000 12000
(1) For application different low-voltage networks and their nominal voltages see Annex B
(2) Equipment with this rated surge voltage may used systems accordance with IEC 60364-4-443.
(4) For more information the surge voltage categories see 2.
3.g. These transverse
surges occur primarily between and circuit
protects the and lines with varistor circuits and
makes the connection the line through collect-
ive spark gap (e.
Table 3. Coordination insula-
tion should take place according 60664.g.
The voltage resistance the devices must co-
ordinated with the protection levels the lightning
and surge protection devices. With
the 3+1 circuit, the external conductors (L1, L2, L3)
are connected the neutral conductor (N) via ar-
restors.2. The neutral conductor (N) connected the
protective earth via collective spark gap. The arrestors must used before resid-
ual current protective device (RCD), would other-
wise interpret the arrested surge current residual
current and interrupt the power circuit.
Surge arrestor type (class II)
Type surge arrestors are used the 3+1 circuit
(e. Where only one value given, relates three-phase, 3-wire systems and describes the voltage
between phases.1.: ÜSM-A).
(3) The slash (“/”) indicates three-phase, 4-wire system. You can find the
relevant technical data the product pages.TBS
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Type 1/type 1+2 lightning arrestors (class I/class
I+II)
Type 1/type 1+2 lightning arrestors are used the
3+1 circuit (e.2. This protection circuit
between and prevents surge currents from trans-
verse voltages being conducted towards PE, the RCD
thus interprets residual current. MCF100-3+NPE-FS, 5096987).1.4 Selection criteria (voltage resistance of
devices protection levels) Selection aid
The rated surge voltage resistance against transient
surges defined according the installation stand-
ard IEC 60664 for the various installation locations. Following
consultation with the local energy provider and ac-
cordance with the VDN Directive, use before the main
meter device also possible.
Surge arrestor type (class III)
Type surge arrestors are used protect against
surges the terminal power circuits. The lower value represents the voltage between the phase and the neutral conductor while
the higher value the voltage between phases
