Datasheet

7P Series - Surge Protection Device (SPD)

Protection against SPD’s short circuits is provided by the overcurrent

protective devices (fuses type gL/gG) recomended.

If the overcurrent protective devices F1 (which are part of the

installation) have a rating smaller than or equal to the maximum

recommended rating for the overcurrent protective devices F2 (back up

fuse), then F2 can be omitted.

7P.0X:

If F1 > 250 A, then F2 = 250 A

If F1<= 250 A, F2 can be omitted

7P.1X, 7P.2X:

If F1 > 160 A, then F2 = 160 A

If F1<= 160 A, F2 can be omitted

Coordination of SPD

Optimal protection from surges requires cascaded coordinated SPDs.

Coordination has the purpose of splitting the energy associated with

voltage across the SPDs and it is achieved by introducing an

impedance between the SPDs, or alternatively, by connecting them

using wires having the minimum length indicated in the figures

below, in order to use the impedance of its own conductor.

V-shape connection

Using a V-shaped connection eliminates transferring downstream the

inductive voltage generated by the surge current in the connecting wire

to the SPD. This increases the protection to the system and equipment

downstream. A limitation of this connection is that the nominal current

for the downstream system is limited to 125A, which is the maximum

current permitted through the double SPD terminals.

For systems where the rated current is greater than 125 A, it is necessary

to connect the SPD in parallel with the equipment (E/I).

Connecting cable

Depending on the type of connection, serial (V-shape) or parallel

(T-shape), ensure that both the maximum cable lengths and minimum

cross section of the connecting wires are respected in accordance with

the information below (IEC 60634-5-534):

The section of the connecting wires (copper) must not be less than:

SPD Type 1: 6 mm

SPD Type 2: 4 mm

SPD Type 3: 1.5 mm

125 A

XII-2012, www.findernet.com