AC and DC Circuit Breakers: Essential Protection for Your Power System
Safety is the most critical component of any solar installation. Circuit breakers act as the frontline defense for your home and your hardware, automatically cutting power in the event of an overload or short circuit. At Smart Tech, we provide a specialized range of breakers designed specifically for the unique demands of photovoltaic (PV) systems.
The Difference: Why You Need Both
It is vital to understand that AC (Alternating Current) and DC (Direct Current) behave differently when a circuit is broken.
- DC Circuit Breakers: These are used between your Solar Panels and the Inverter, or between your Batteries and the Inverter. DC current is constant and harder to “extinguish” when a spark (arc) occurs. Our DC breakers are engineered with internal magnets to pull the arc away from the contacts, ensuring a safe shutdown.
- AC Circuit Breakers: These are installed on the Output side of your Inverter or within your home’s main DB board. They protect your household appliances and the inverter itself from surges coming from the grid or internal wiring faults.
Our Range of Protection Gear
- DC Miniature Circuit Breakers (MCB): Available in 16A to 63A, ideal for string protection.
- Molded Case Circuit Breakers (MCCB): Heavy-duty protection for high-capacity battery banks.
- Dual Pole Breakers: Ensuring both the positive and negative lines are isolated simultaneously for maximum safety.
- Din Rail Compatible: All our breakers are designed to fit standard South African DB boards and weather-proof combiner boxes.
No. This is a major fire hazard. AC breakers rely on the “zero-crossing” of the AC cycle to extinguish an arc. Since DC current is continuous, an AC breaker may fail to stop the flow of electricity during a fault, leading to a sustained fire inside your DB board.
This depends on the Short Circuit Current (Isc) of your solar panels. Typically, you should choose a breaker rated at roughly 1.25 to 1.5 times the total amperage of your string.
Yes. For a solar installation to pass a Certificate of Compliance (COC) in South Africa, you must use breakers that meet national safety standards. Smartechs sources breakers that are tested for reliability and compliance.