Off grid solar inverters are very popular in foreign markets. Off grid solar inverter can solve their power supply problems. However, in foreign countries, the mains power in many countries or regions are not very stable or even blackout. With the current mature inverter product technology, off grid solar inverter on the market can be connected to the mains, and the mains can be used as a supplement. When the inverter does not generate enough electricity from the solar panels or the battery power is low, the inverter can switch to the mains and continue to supply power to the load, thereby further ensuring the stability and reliability of the power supply. However, the mains mode of the off grid solar inverter should be used with caution. The instability of the mains power will bring risks to the off grid inverter.
The mains priority mode of the off grid inverter mainly relies on the mains as the main power source. If the mains power voltage in the user's area is unstable, the basis for the "priority" of the mains will be lost. Frequent switching may even accelerate the loss of the inverter.
So what risks does an unstable mains power bring to the off grid solar inverter when using the mains mode?
1. Overvoltage or undervoltage
The grid voltage exceeds the input range allowed by the inverter for a long time or momentarily. The nominal voltage is 220V, and the mains voltage often fluctuates to 170V or 250V or above. This will cause the inverter to detect abnormal voltage and frequently switch to battery power mode, resulting in confusion in mode switching. The inverter will shut down for protection, affecting the stable power supply of the load equipment. Overvoltage may damage the inverter motherboard. Overvoltage or undervoltage may cause damage to the connected electrical equipment (such as refrigerators, air conditioners, computers, etc.) or shorten their lifespan.
2. Frequent power outages and recovery
The mains power in some countries is sometimes available and sometimes not, and there may be multiple power outages in a day. If the mains priority mode is used, the inverter will switch to battery power every time the power is cut off. When the mains power is restored, the battery current is insufficient and it will switch back to mains power. Frequent switching will put pressure on the components of the inverter and shorten its lifespan. Frequent power outages and restarts are also very detrimental to the stable operation of motor loads (such as air conditioners, refrigerator compressors, etc.) and electronic equipment (such as computers, servers, etc.). When the mains power is restored, the mains power recovery moment is often accompanied by a surge in voltage and current. Even if the duration is extremely short (milliseconds), the high energy surge is enough to instantly break through the inverter motherboard, and even damage the energy storage battery part and load equipment.
3. Harmonic distortion and frequency instability
The inverter needs to synchronize with the voltage and frequency of the mains before switching to its mains priority mode. If the mains power waveform is distorted, or the frequency (50/60Hz) fluctuates too much, it will cause the inverter to fail to synchronize, trigger a fault code or fail to switch to the mains mode. Harmonics may cause some sensitive equipment to work abnormally or heat up. In this case, it is not reliable to use the mains priority mode, and it may even be impossible to enter the mode normally.
Working mode suggestions for off grid solar inverter
There are several common working modes for off grid solar inverter, such as solar priority, mains priority, battery priority, etc. The main feature of off grid solar inverter is that they do not rely on the mains power, operate independently, and use solar power for self generation and self use. Therefore, the mains priority mode is only an optional power supply supplement, not the main power supply mode, especially for unstable foreign mains power. The mains priority mode of off grid solar inverter needs to be used more cautiously. Unstable mains may not only fail to provide "stability guarantee", but may also damage the inverter itself, the connected responsible equipment, and the energy storage battery system.
Xindun recommends that users use solar priority mode during the day to maximize the use of solar energy. In solar priority mode, while the solar power meets the power of the load equipment, the extra solar power is used to charge the battery, reducing dependence on the mains.
On cloudy days and at night, switch back to battery priority mode, which can make full use of the power stored in the battery to ensure continuous power supply to the load equipment. When the battery discharge voltage reaches the set value, switch to mains power supply. Avoid long term setting to mains priority mode. When the battery is low, if the mains is relatively stable, the inverter will automatically switch to mains priority mode to supplement power.
Xindun recommends that users switch to mains priority mode manually only when the mains power is relatively stable and necessary, and switch back to battery or solar priority mode as soon as possible after the battery is fully charged. Users should also regularly inspect and maintain the inverter to ensure that its functions are normal, improve its ability to cope with unstable mains power, and extend the service life of the inverter and related equipment.
If you want to know more about Xindun off grid solar inverter, you can leave your information and needs in the customer service window at the bottom of the website (https://www.xindun-power.com/), and Xindun will contact you as soon as possible during working hours.
