PV distribution board 2-string DC 1000V T1 T2 Doktorvolt 4487 DV-4487-FOT

Two-string photovoltaic distribution box for DC side protection

The Doktorvolt DV-4487-FOT photovoltaic distribution box is a complete solution for protecting PV installations on the direct current side. It has been designed to protect crystalline photovoltaic modules and is equipped with two pairs of MC4 solar connectors - complete male and female connections are included in the set, eliminating the risk of using incompatible connectors (standards IEC 62548 and IEC 60364-7-712:2017 strictly prohibit mixing DC connectors from different manufacturers due to the risk of installation fire).

The enclosure, made of technopolymer in gray RAL 7035, provides high mechanical and chemical resistance. The polycarbonate door is robust and impact-resistant, and the EPDM rubber gasket guarantees IP65 tightness - the distribution box is dust-tight and protected against water jets from any direction. Stainless steel screws further increase the durability of the construction in outdoor conditions. The enclosure dimensions are 215 × 210 × 100 mm, and after installing PG11 glands and MC4 connectors, the enclosure measures 215 × 240 × 100 mm, allowing for compact surface mounting even in limited spaces.

T1+T2 Surge Protection

The core of the distribution box is a pair of DC surge arresters 2× DC T1 T2 3P 1000V - two-stage protection in one device. Class T1 (protection against lightning strikes) combined with class T2 (protection against operating surges) provides comprehensive protection for the photovoltaic installation against both direct lightning strikes and so-called atmospheric and switching surges.

The maximum operating voltage is 1000 V DC (Un = Uc), and the device tolerates an impulse current Iimp of 12.5 kA. The nominal discharge current In reaches 20 kA, and the maximum current Imax is 40 kA. The protection level Up remains below 2.0 kV, which effectively reduces surges to safe values for the connected PV modules. The arresters comply with the IEC61643-11 standard and hold the CE certificate.

Wiring and Solar Connections

Inside the distribution box, 1×6 mm² solar wires of voltage class 0.6/1 kV are used - black for the negative pole and red for the positive - as well as an H07V-K 16 mm² control cable in yellow-green as a protective conductor. The working conductor cross-section was selected to safely carry the current generated by two strings of PV modules at voltages up to 1000 V DC.

An additional set of MC4 solar connectors (4× female + 4× male) is included with the distribution box, enabling a fast and secure connection to the string cables leading from the photovoltaic modules. The MC4 connectors operate at a voltage of 1000 V DC, withstand an impulse voltage of 8 kV, and have an IP67 protection rating, which means full dust tightness and resistance to water immersion for a specified time.

Manufacturing Quality and Standards

The manufacturer has implemented a management system certified by TÜV SÜD according to the ISO 9001:2015 standard, guaranteeing the repeatable quality of every unit. The distribution box meets the requirements of the EU directive 2002/95/EC (RoHS) and the CEI 23-48 standard, and holds separate CE certificates for the enclosure and the protection module - this is important during installation acceptance by a network distributor or a supervision inspector.