How to choose the right circuit breaker for a solar PV system?

Choosing the right circuit breaker for a solar PV system is critical. A circuit breaker protects the system from overloads and short circuits, preventing fires and damage to panels, inverters, and wiring. Using a breaker that is too small can cause it to trip constantly; one that is too large won’t trip when needed, risking danger.

How many amps does a solar breaker need?

The breaker in the home’s main panel controls the flow of solar power into the home. For a total solar system size of 3kW, the maximum AC current entering the home is around 13 amps. 125% of 13 amps is 16.25 amps, so a 20-amp breaker is needed.

Do solar panels need a breaker?

Solar panels are grouped into strings, and each string needs a breaker to protect the wiring between the panels and the inverter. The inverter, which converts DC power from the panels to AC power for home use, requires breakers on both its input (DC) and output (AC) sides.

What breaker do I need for a 3KW Solar System?

For a total solar system size of 3kW, the maximum AC current entering the home is around 13 amps. 125% of 13 amps is 16.25 amps, so a 20-amp breaker is needed. A 5kW system has a maximum AC current of about 21 amps. 125% of 21 amps is 26.25 amps, so a 30-amp breaker works.

Are Solar System Breakers dangerous?

Yes. Solar breakers are designed to handle DC power, which is more dangerous than AC because it doesn’t alternate, making it harder to interrupt. They also have higher durability for outdoor use, as many solar system breakers are installed in outdoor enclosures.

Should I use a standard AC circuit breaker in a DC application?

A common but dangerous mistake is using a standard AC circuit breaker in a DC application to save costs. This should never be done. The fundamental difference lies in how they handle an electrical arc—the dangerous surge of energy that forms when a circuit is interrupted.