DC Solar Isolator Switch 50A 1000VDC

What Is a DC Isolator Switch?

A DC isolator switch is a mandatory safety component in any solar PV installation. It provides a physical means to disconnect the solar array from the inverter input, allowing safe maintenance and emergency shutdown of the DC side of the system without needing to cover or remove the panels.

Unlike AC circuit breakers, this rotary switch is specifically designed to interrupt DC current — an important distinction because DC electrical arcs are far more difficult to extinguish than AC arcs at the same voltage and current level.

Specifications

• Rated current: 50A
• Rated voltage: 1000V DC (dual-rated at 800V DC)
• Poles: 2P (positive and negative)
• Mounting: DIN rail or panel mount
• Mechanical cycles: 10,000 operations
• Electrical cycles: 300 operations under rated load
• Enclosure rating: IP20 (suitable for installation inside an enclosure)
• Standard: IEC 60947-3

Installation

This isolator is typically mounted inside a weatherproof enclosure positioned between the solar array and the inverter DC input terminals. Both the positive and negative conductors must pass through the switch (2-pole operation). For systems with multiple panel strings, install a combiner box upstream of the isolator.

The isolator must be accessible for operation without tools and clearly labelled as the DC array disconnect.

Compliance

South African National Standard SANS 10142-2 (Wiring of Premises — Part 2: Small-Scale Embedded Generation) requires a means of isolation on the DC side of grid-tied and hybrid solar installations. This switch satisfies that requirement when correctly installed.