Photovoltaic systems are exposed in large open spaces, usually in the field or on top of buildings. Charged rain clouds that accumulate over tend to release electrical charges in the form of thunderbolts. In this case, a voltage surge is likely to occur. The wider the site, the greater the potential for damage. A surge can easily damage electronic equipment to the point of catastrophic failure. There is also the potential for personal safety to be endangered if someone is present when the surge occurs.

A surge is a transient disturbance that causes an instantaneous voltage on the power grid to exceed the rated normal voltage range under certain conditions. Usually, this transient does not last for too long, but it may be of a high magnitude. It may be a sudden high in just one millionth of a second, such as lightning, or the moment when an inductive load is disconnected, or a large load is connected, which will have a great impact on the power grid. In most cases, if the equipment or circuit connected to the power grid has no surge protection measures, it is easy to damage the device, and the degree of damage will be related to the withstand voltage level of the device.
 

01
How does the surge occur and what are the effects?

Causes of surges (transient pulses) include lightning, poor grounding, inductive load switching, utility power troubleshooting, and electrostatic discharge ( ESD), the results of which can result in data loss (or damage) or even equipment destruction, including Lightning is the most destructive. The cumulative effect of multiple small surges causes degradation of semiconductor device performance, equipment failure, and shortened lifespan, ultimately leading to production shutdowns or reduced productivity.
 

02
About Surge Protector

Surge protector is an indispensable device in the surge protection of electronic equipment. It used to be called "surge arrester" or "overvoltage protector". The function of the surge protector is to limit the instantaneous overvoltage that enters the power line and signal transmission line within the voltage range that the equipment or system can withstand, or to discharge a strong current into the ground to protect the protected equipment or system from impact. and damaged.

 

03
How do we choose a surge protector?

The correct choice of surge protector depends on three values: 

• Maximum continuous operating voltage: The minimum value of the maximum continuous operating voltage of the surge protector should be 1.15 times the phase voltage (Uo). If the maximum continuous operating voltage is larger, the service life of the surge protector will be longer.
• Voltage protection level: The overvoltage category of the device must be higher than the voltage protection level of the surge protector.
• Nominal Discharge Current: The peak waveform that the SPD can withstand after repeated surges ( 8/20 µs for Type 2 SPD).

Please exercise caution when purchasing a solar surge protection device. This is mainly due to the fact that there are various products on the market that have almost no effect under the guise. We recommend that the best way to buy the right product is primarily to research a specific model. Of course, you should pay careful attention to several quality marks, and it is of course essential to know the performance level of the product. In general, don't expect too much from a cheap surge protector. Low price means low cost. These devices are very likely to use simple and cheap varistors, which make the capacity very limited. During daily use, once a large surge or spike occurs, the user's circuit system will not be protected. Of course, a high-priced solar DC surge protector does not mean good quality.