PV distribution board 2-string DC 1000V T2 Doktorvolt 9474 DV-9474-FOT-258-DC

Surge protection for photovoltaic installations

The Doktorvolt brand DC photovoltaic distribution board has been designed to protect crystalline modules on the direct current side. Equipped with two T2 class surge arresters with a rated voltage of 1000V DC, it effectively protects circuits from surges generated by atmospheric discharges and network switching operations.

The device's protection parameters testify to its high efficiency - the rated current In is 20 kA, and the maximum peak current Imax reaches 40 kA. The voltage protection level Up < 2.0 kV effectively limits the amplitude of rising impulses within a fraction of a second to values safe for the connected PV modules. The varistor-based design ensures a rapid response to voltage spikes and durability under continuous operation.

The enclosure accommodates 8 modules in one row and supports two DC strings, making it a suitable solution for small and medium-sized photovoltaic installations. The set includes factory-installed MC4 solar connectors (4x female and 4x male) and an additional connection set - the manufacturer emphasizes that IEC 62548 and IEC 60364-7-712:2017 standards do not allow the use of DC connectors from different manufacturers due to the risk of contact resistance and overheating of connections leading to installation fires.

Enclosure and operating conditions

The IP65 protection rating guarantees the enclosure's tightness against dust and water jets from any direction - making the distribution board suitable for outdoor conditions without the need for additional shielding. The enclosure, made of technopolymer, is characterized by resistance to mechanical impacts confirmed by the IK07 class, which is important when mounting on facades or roofs exposed to hail.

The polycarbonate door ensures dimensional stability and thermal resistance. The EPDM rubber gasket maintains flexibility across a wide temperature range - it does not harden in frost nor soften under intense sunlight. Stainless steel screws eliminate the risk of thread corrosion during multiple openings of the box during servicing.

The dimensions of the enclosure itself are 215 × 210 × 100 mm, and after installing the PG-11 cable gland and connectors - 215 × 240 × 100 mm. The gray color RAL 7035 allows the device to be discreetly integrated into the building facade. Surface mounting enables quick placement of the distribution board without interfering with the wall structure.

Wiring and completeness of delivery

The distribution board is factory-wired with 1×6 mm² solar cables (black and red) with an insulation voltage of 0.6/1 kV, which meets the requirements for DC circuits up to 1000V. The yellow-green H07V-K protective earth wire with a cross-section of 16 mm² serves as the protective conductor (PE). All cores are appropriately selected for the current-carrying capacity of the photovoltaic strings.

The solar connectors installed in the device operate at a voltage of 1000 V DC, withstand an impulse voltage of 8 kV, and have an IP67 protection rating. The operating temperature range from -40°C to +105°C allows the distribution board to be used in both Polish winter conditions and under strong summer sunlight. Contact resistance below 0.5 mΩ minimizes power losses at the connections.

Certificates and quality standards

The manufacturer has implemented a management system certified by TÜV SÜD, confirming the repeatable quality of the production process. The distribution board meets European standard requirements - it holds CE certificates, a declaration of conformity with EU directive 2002/95/EC, RoHS certification, and complies with the IEC 61439 construction standard. Production takes place in Poland using components from European suppliers.