Page 482 - 35_DS702_E_2014_Lightning_Protection_Guide

SPD class symbols
Characteristic Symbol Description
D1 impulse (10/350 μs), lightning impulse current ≥ 2.5 kA / core or ≥ 5 kA / total
• Exceeds the discharge capacity of –
Discharge capacity
of an arrester (accord- C2 impulse (8/20 μs), increased impulse load ≥ 2.5 kA / core or ≥ 5 kA / total
ing to the categories • Exceeds the discharge capacity of –
of IEC 61643-21 C1 impulse (8/20 μs), impulse load ≥ 0.25 k / core or ≥ 0.5 kA / total
(EN 61643-21)) • Exceeds the discharge capacity of

Load <
Protective effect of Test level required for the terminal device: 1 or higher
an arrester (limitation Test level required for the terminal device: 2 or higher
below the test levels
acc. to IEC 61000-4-5 Test level required for the terminal device: 3 or higher
(EN 61000-4-5)) Test level required for the terminal device: 4
Energy coordination Arrester has a decoupling impedance and is suitable for coordination with
(with another an arrester marked with
Yellow/Line arrester) Arrester suitable for coordination with an arrester with decoupling impedance

Assignment of the SPD classes to the LPZ transitions
Exemplary assignment of SPD classes to LPZ transitions
Conductor routing Arrester solution
To LPZ 1 To LPZ 2 To LPZ 3
Combined arresters

From LPZ 0 A
Cascaded arresters
Combined arresters
Surge arresters or
From LPZ 0 B
Cascaded arresters
Combined arresters –
From LPZ 1
Surge arresters – or
Combined arresters –
– –
From LPZ 2
Surge arresters – –
– –

www.dehn-international.com LIGHTNING PROTECTION GUIDE 481