CEI EN 50539-11 PDF

This European Standard defines the requirements and tests for SPDs intended to be installed on the d.c. side of photovoltaic installations to protect against induced and direct lightning effects. These devices are connected to d.c. power circuits of photovoltaic generators, rated up to 1 500 V.

It takes into account that photovoltaic generators: 

-behave like current generators, 

-that their nominal current depends on the light intensity, 

-that their short-circuit current is almost equal to the nominal current, 

-are connected in series and/or parallel combinations leading to a great variety of voltages, currents and powers from a few hundreds of W (in residential installations) to several MW (photovoltaic fields).

The very specific electrical parameters of PV installations on the d.c. side require specific test requirements for SPDs. SPDs with separate input and output terminal(s) that contain a specific series impedance between these terminal(s) (so called two port SPDs according to EN 61643-11) are currently not sufficiently covered by the requirements of this standard and require additional consideration.

NOTE In general SPDs for PV applications do not contain a specific series impedance between the input/output terminals due to power efficiency considerations.

SPDs complying with this standard are exclusively dedicated to be installed on the d.c. side of photovoltaic generators. PV installation including batteries and other d.c. applications are not taken into account and additional requirements and tests may be necessary for such applications.

SPDs for which the manufacturers declares short circuit mode overload behaviour, shall require specific measures to ensure that such devices will not endanger the operator during maintenance and replacement due to possible d.c. arcing.