PV DC distribution board 1000V T2 Phoenix Contact PG Doktorvolt 4357 DV-4357-FOT

PV string protection in a single enclosure

The Doktorvolt DC photovoltaic distribution board is a complete solution for protecting a single string in a PV installation with a voltage of up to 1000V DC. Inside the surface-mounted enclosure, a Phoenix Contact VAL-MS 1000DC-PV/2+V/40 surge protective device is installed, providing Type 1+2 protection - capable of both absorbing part of the impulse current during a direct lightning strike on the line and effectively suppressing surges induced in the rest of the installation.

The enclosure saves space thanks to its compact 142 × 210 × 100 mm design and occupies only 4 modules on the TH35 rail. Pre-drilled holes with cable glands (1× PG11 + 4× PG7) allow for the direct entry of string and grounding wires at the box - without additional accessories.

IP65 enclosure for outdoor applications

The IP65 protection rating means full dust tightness and resistance to water jets from any direction. The technopolymer enclosure in RAL 7035 grey does not corrode - it is ideal for facades, flat roofs, and support structures. The polycarbonate door ensures rigidity while maintaining a low overall weight. The EPDM rubber seal maintains flexibility even with large temperature differences - typical for year-round outdoor operation. Stainless steel screws guarantee a durable closure without rust.

Phoenix Contact surge protective device parameters

The installed surge protector supports a maximum voltage of Uc = 1200V DC, which, given a string operating voltage of Un = 1000V DC, provides a safety margin of approximately 20%. The test current In = 40kA (8/20 µs) defines the absorption capacity during multiple strikes - a key parameter in regions with frequent thunderstorms. The protection level Up < ~4 kV effectively reduces the surge amplitude to values safe for inverter inputs.

The surge protector has 3 poles (plus a common quenching element), allowing it to protect both working conductors and the string negative in a bipolar configuration used in PV installations above the voltage threshold.

Standards and certificates

The manufacturer Doktorvolt operates under a management system certified by TÜV SÜD according to the ISO 9001:2015 standard. The distribution board itself meets the requirements of CE and RoHS directives, and its design is based on the IEC 61439 standard. The surge protective device also complies with the classification according to IEC 61643-31 and the European EN 50539-11, which specifies the requirements for protective devices used in photovoltaic circuits.