Distributed configuration with string inverter

If PV power plants with distributed string inverters are used, most of the power cables are installed on the a.c. side.

In the event of a direct lightning strike, the a.c. cables serve as an equipotential bonding conductor between the "local" earth potential of the PV array and the “remote” equipotential bonding surface of the in feed transformer.

Therefore, type 1 arresters are used on the a.c. side. Type 2 SPDs are sufficient for the d.c. side of the string inverter since they basically limit induced interference impulses.

Comprehensive protection for electronic components

Type 2 arresters are installed at the d.c. input of the inverter. These arresters also protect the modules in close proximity. Type 1 combined arresters are installed on the a.c. side of the string inverter and the low-voltage side of the infeed transformer. The communication interfaces are also provided with adequate surge protective devices.

Protection against direct lightning strikes

Air-termination systems are used to protect the PV array and operations building from direct lightning strikes. These systems are often installed on the metal mounting structures.

 

Sample application:

Distributed configuration with string inverter

B - DEHNguard® M YPV

d.c. side: Type 2 arrester specially designed for application in PV systems. Protects the DC side of the inverter against surges from inductive couplings.

Product details

B - DEHNcube YPV SCI 1000

Alternatively: Type 2 arrester that provides comprehensive protection for a PV system in an enclosure. It is mounted directly upstream of the inverter and is available in two versions, 1 MPPT and 2 MPPT.

Product details

C - DEHNshield®

a.c. side: Combined lightning current and surge arrester. Protects the AC side of central and string inverters or AC-coupled battery storage systems.

Product details

D - BLITZDUCTOR® XTU

Data interface: Combined arrester that protects balanced data interfaces (z.B. RS 485). Via the integrated actiVsense® Technology the arrester automatically detects the operating voltage of the useful signal and optimally adapts the voltage protection level to it.

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E - DEHNpatch CLE IP 66

Complete unit consisting of surge protection and outdoor enclosure (IP 66). Protects, e.g. IP camera systems.

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F - UNI earthing clamps/saddle clamps

Equipotential bonding / Earthing: Clamps suitable for integrating the mounting systems of PV installations in the functional equipotential bonding / the functional earthing or the lightning equipotential bonding.

Product details

G - Angled air-termination rod

10 mm air-termination rod fixed to the metal support structure of PV modules to protect them from direct lightning strikes. Total length 1 m.

Product details