PV distribution board 2-String DC 1000V T2 PG Phoenix Contact Doktorvolt 4432 DV-4432-FOT

DC surge protection in a compact IP65 enclosure

The Doktorvolt photovoltaic distribution board is designed to protect crystalline modules on the direct current side. It is equipped with two T2 class surge arresters - high-quality components in the field of current protection. The design includes two independent DC circuits (strings), allowing for the connection of two photovoltaic module strings and their safe connection to the inverter.

The enclosure, made of technopolymer, is characterized by resistance to weather conditions and UV radiation. The IP65 protection rating means full dust-tightness and protection against water jets from any direction - the distribution board can be mounted directly on a building facade or on the PV installation support structure without additional shielding. The polycarbonate door provides mechanical resistance while maintaining a low total device weight.

The EPDM rubber seal maintains flexibility across a wide temperature range, and the stainless steel screws eliminate the risk of thread corrosion during years of exposure to moisture. The set includes 1× PG-11 cable glands (for main conductors) and 8× PG-7 (for input strings), allowing for flexible cable configuration adjustment to a specific installation.

Dimensions and enclosure design

The dimensions of the enclosure itself are 215 × 210 × 133 mm, and after mounting the PG glands, the width increases to 240 mm. The gray color RAL 7035 is a standard in the distribution board industry - the neutral shade is unobtrusive on the facade and blends well with most building surfaces. The enclosure is designed for 8 modules in one row, which corresponds to a typical string distribution board for small PV installations.

DC protection parameters

The maximum operating voltage of the arresters is 1170V DC, which provides a safety margin for installations operating at a nominal system voltage of up to 1000V. The nominal discharge current In = 15 kA and the maximum current Imax = 40 kA demonstrate the device's ability to absorb energy from atmospheric discharges and switching surges generated by the inverter. The voltage protection level Up < 3.7 kV effectively limits the pulse amplitude to values safe for the connected electronics.

Internal wiring and certificates

Internal connections are made using H07V-K flexible wire with a cross-section of 16 mm² in yellow-green (protective conductor PE). Such a large cross-section minimizes power losses and allows for the trouble-free transfer of string currents reaching several dozen amperes.

The manufacturer declares compliance with the following standards:

• EN 50539-11 - European standard for surge arresters in photovoltaic installations,
• CEI 23-48 - standard regarding electrical installation equipment,
• RoHS, Deca-BDE, Eu 2002/95/EC.

The Doktorvolt production management system is certified by a recognized external body and according to the ISO 9001:2015 standard. The arresters have classifications according to eCl@ss and ETIM systems, which facilitates their identification in professional costing and warehouse software.