Connection
System Voltage
Power (Watts)
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This breaker calculator finds the correct circuit breaker ampere rating for each connection in your solar system. A breaker that's too small trips constantly; one that's too large won't protect your wiring from overheating in a fault — so getting the rating right is a real safety matter, not just a convenience.
Pick the connection you're protecting — PV array to hybrid inverter, hybrid inverter to battery, or hybrid inverter to load — and enter the watts. The tool divides watts by the relevant voltage to get amps, then adds a 25% safety factor as required for continuous solar loads, and rounds up to a standard breaker size. DC connections use your system voltage (12/24/48V), while the AC load side uses mains voltage, because the same wattage draws very different current on each side.
Use this when wiring or upgrading your setup. Always confirm the final sizing and your wire gauge with a licensed electrician — these are planning estimates, not a code-compliant engineered design.
Common questions about sizing breakers for your solar setup.
Divide the watts by the voltage of that connection to get amps, add a 25% safety factor, and round up to the next standard breaker. This calculator does it per connection type (PV-to-inverter, inverter-to-battery, inverter-to-load) and recommends products.
The same power draws far more current at low DC voltage than at 230V AC. For example, 1,000W is about 83A at 12V DC but only ~4.3A at 230V AC — so DC-side breakers and cables must be much larger.
Solar circuits run continuous loads, so standards require sizing conductors and breakers to 125% of the expected current. The 25% uplift keeps wiring within safe temperature limits and reduces nuisance tripping.
Yes — that DC link carries high current and needs its own correctly sized breaker. The Breaker Sizing calculator focuses specifically on the battery-to-inverter connection.
