Breaker amp rating for inverter
The breaker amp rating for an inverter depends on several factors, including:
- Inverter power output: The maximum power output of the inverter, measured in watts (W).
- Inverter efficiency: The efficiency of the inverter, which affects the amount of power it can deliver.
- Cable size and length: The size and length of the cables connecting the inverter to the load (e.g., solar panels, battery bank).
- Load type and characteristics: The type and characteristics of the load being powered by the inverter (e.g., resistive, inductive, capacitive).
Here are some general guidelines to help you determine the breaker amp rating for an inverter:
Resistive loads (e.g., lights, appliances):
- For a single-phase inverter, use the following formula: Breaker amp rating = Inverter power output (W) / 230V (or 120V for a 120V system)
- For a three-phase inverter, use the following formula: Breaker amp rating = Inverter power output (W) / 400V (or 208V for a 208V system)
Inductive loads (e.g., motors, pumps):
- Add 20-30% to the inverter power output to account for the inductive load's reactive power consumption.
- Use the modified inverter power output value in the formula above.
Capacitive loads (e.g., LED lighting, power supplies):
- Subtract 10-20% from the inverter power output to account for the capacitive load's reactive power consumption.
- Use the modified inverter power output value in the formula above.
Example calculation:
Let's say you have a 2,000W single-phase inverter with an efficiency of 95%. You want to power a resistive load, such as a set of LED lights.
- Calculate the inverter's maximum power output: 2,000W x 0.95 (efficiency) = 1,900W
- Calculate the breaker amp rating: 1,900W / 230V = 8.26A (round up to the nearest standard breaker rating, e.g., 10A)
In this example, you would use a 10A breaker to protect the inverter and the load.
Remember to always follow the manufacturer's recommendations for the inverter's breaker rating and to consult with a licensed electrician if you're unsure about the calculation or installation.