Solutions for solar breaker tripping off

Solutions for solar breaker tripping off

“Why is the AC circuit breaker of my solar system always tripping off? I was in my office and could not tackle it at all until I was back to my home. This condition takes lots of losses, it is very annoying.”

Do you often receive customer complaint calls regarding the solar breaker tripping off? The AC breaker tripping off may be the most common solar energy customer complaint, this cannot be ignored.

In fact, when installing a set of solar system, we need to ensure that all parts are installed in the correct way. In addition to solar panels, mounting material and inverters, there are also important DC and AC breakers.

Today, we will learn more about why AC breakers trip off frequently and how to solve this problem.

Firstly, let us get a clearer thought of what an AC breaker is?

An AC circuit breaker is also called Solar AC breaker.

  1. Electrical isolation function: during installation and maintenance, cut off the electrical connection between photovoltaic modules, inverters, power distribution boxes and the power grid to provide a safe environment for operators. This cut off is active and a manual operation.

  2. Safety protection function: it provides AC circuit protection. In case of overcurrent, overvoltage, short circuit, over temperature and leakage current, it can automatically cut off the circuit to protect the safety of people and equipment. This action is realized automatically by the breaker.

What are the main causes of AC breaker tripping off?

  1. The cable is too thin and not chosen in accordance with AS3008 regulation.

  2. When the inverter AC output is far away from the meter box, the cable shall be lengthened and increased, and 10% of the carrying current margin shall be realized.

  3. The AC breaker is incorrectly configured.

  4. The quality of AC breaker is poor.

  5. The temperature is too high.

The cable is too thin and not chosen in accordance with AS3008 regulation.

AS3008 has clear provisions on the current that can be carried by cables under different conditions. It can be seen from the following table that in sunny weather, when the conduit is close to the wall surface, the carrying current of 6mm ² wire is 39A. The standard models of electrical switches are 16a, 20a, 25a, 32a, 40a, 63a, 100a. If the maximum output current of the inverter in the photovoltaic system is ≤ 30A, we can choose 32A AC breaker, and so on.

If a single-phase 8KW machine has a maximum output current of 34.78A, but you choose a 32A switch, your AC breaker will frequently trip off at noon in summer when the peak output power is easy to reach, because the current is too high!

When the inverter AC output is far away from the meter box, the cable shall be lengthened or increased, and 10% of the carrying current margin shall be provided.

The AC breaker is configured incorrectly.

In addition to the above two issues, when we select an appropriate AC breaker with reference to AS3008. Also, we need make sure the size of the AC breaker to be less than the maximum current carried by the cable in the installation environment, and the maximum carrying current of the AC breaker must be greater than the maximum AC current of the inverter by more than 10%.

The quality of AC breaker is poor.

The working temperature, protection and fire protection grade shall be determined according to the operating environment. Generally, DC switches with good quality can work stably from - 40 ° to 60 °. The protection grade of common external DC switch is IP65. After the installation of the built-in DC switch, the whole machine can pass IP65. Sometimes your AC breaker keeps tripping off, but you find that your photovoltaic system has no problems, and your AC breaker is hot, there is a burning smell, and looks damaged. It is likely that your AC breaker is of poor quality. Time to replace it.

Temperature is too high

This kind of fault is very common. The rated current marked on the circuit breaker is the maximum current that the device can carry for a long time when the temperature is 30 ° C. The carrying capacity decreases by 5% when the temperature rises by 10 ° C. The circuit breaker is also a heat source because of the existence of contacts. There are two reasons for the high temperature of the circuit breaker: one is the poor contact between the circuit breaker and the cable, or the poor contact of the circuit breaker itself, resulting in a large internal resistance, which causes the temperature of the circuit breaker to rise; Second, the closed environment where the circuit breaker is installed is not good for heat dissipation. We can rewire or replace the circuit breaker directly.


An excellent inverter should not only have beautiful specification, but also be more practical and durable. This is not only reflected in its functions, but also in the experience of installers and customers, which plays a vital role in the photovoltaic system. Each Energy has made unparalleled efforts in terms of the experience of end customers and the convenience of installers.

In terms of the recommended configuration for installers, it has provided the recommended wire thickness and the matching AC breaker that meet the standards. The design of AC output port presents a very simple casing in-line design, which is convenient and safe to install, and reduces the possibility of AC breaker tripping off.