Operating voltage PV
The operating range of the inverter is usually located between the starting voltage and the maximum voltage. This interval is indicated in volts.
Controller
Built-in Maximum Power Point Tracking (MPPT) system for monitoring the maximum power points of photovoltaic modules in solar panels. It determines the most optimal ratio of voltage and current drawn from the solar panels, thereby ensuring maximum performance of individual strings (chains of series-connected panels). An
MPPT controller is useful under any external weather changes, allowing solar panels to generate power even in cloudy conditions. Modern inverter models can contain either one or
several MPPT trackers (up to six), which allow for the connection of multiple arrays with different orientations and angles of inclination, thereby eliminating the mutual influence of one array on another. Each MPPT controller output is designed to connect one string.
Protection
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Overload protection. A protection system against connecting an off-design load whose power consumption exceeds the capabilities of the inverter for solar panels. In such situations, the power to the outlets is automatically turned off, since overloading the device promises failure and even fire. Triggering of the protection is usually accompanied by a sound and/or light signal.
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Overheat protection. This protection is triggered when the temperature inside the inverter rises critically. When such situations occur, the device turns off, which avoids breakdowns. In the future, some models will automatically turn on when the temperature normalizes, while others must be turned on manually. Note that overheating is caused not only by malfunctions, but also by completely normal reasons - for example, long-term operation at high air temperatures. Typically, overheating protection is accompanied by a sound and/or light signal.
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Protection against ↑ or ↓ battery voltage. A protection system that prevents the inverter from being supplied with excessively high or excessively low voltage from the batteries. When the operating voltage range is exceeded, the device automatically turns off to avoid breakdowns and other troubles. A sound and/or light signal can warn of protection activation.
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Short circuit protection.... Protection that is triggered when the output current increases critically (for example, due to a foreign metal object getting between live parts of the load). To avoid breakdowns and failure, the power at the inverter output is automatically turned off. Triggering of the protection system is usually accompanied by a sound and/or light signal.
— Reverse polarity protection. Protection system in case of incorrect polarity of connection. If the “plus” and “minus” do not match, the inverter is disconnected from the power supply in order to avoid damage to the electronic components. Notification of protection activation is often provided by a sound and/or light signal.
— Protection class. The class of protection against dust and moisture provided by the inverter housing for solar panels. Indicated according to the IP standard by two numbers: the first (from 1 to 6) means resistance to penetration of foreign objects and dust, the second (from 1 to 8) - protection from moisture. The higher the number, the higher the level of protection provided. Also note that instead of the first digit in the designation of the protection class, “X” may be indicated - for example, IPX7. In this case, the device is not certified for dust protection, although in fact the level of such protection may be quite high. So, in the example with moisture resistance “7”, the case can be completely immersed in water - which means it is closed very tightly from dust.
The IP protection level is especially important to consider when choosing models for outdoor use and installation in rooms with high humidity levels - they are the ones most susceptible to adverse environmental influences. A high IP class will guarantee stable operation of the inverter for solar panels in such difficult conditions.Display
The presence of its own display provides more visual control of the device’s operation. Various operating characteristics can be displayed on the screen: current electricity generation, load level, voltage and frequency in the network, operating mode, battery charge, etc. Inverters are equipped with both simple monochrome displays and full-fledged color panels for visual visualization of parameters.
Noise level
The noise level in decibels (dB) produced by the inverter during operation. The lower this indicator, the more comfortable the use of the equipment will be, which is especially important for residential premises.
Note that decibels are a non-linear quantity, so the easiest way to assess the noise level is to use comparative tables. Here is a simplified table for the range that most modern inverters fall into:
35 dB – conversation in muted tones;
40 dB – quiet conversation; maximum noise level allowed in residential premises during the daytime;
45 – 50 dB – conversation in a normal tone;
55 dB - background noise in an office without special noise sources;
60 dB - loud conversation;
65 dB - city street with average traffic intensity;
70 dB - a conversation between several people in a raised voice.
Casing protection class
The protection class of the housing is traditionally indicated according to the IP standard - the “IP” marking with two numbers. The first describes protection against the penetration of dust and foreign objects. The following options may occur:
— 2. Protection against objects with a thickness of 12.5 mm or more, prevents the penetration of fingers.
— 3. Protection against objects with a thickness of 2.5 mm, in particular many tools.
— 4. Protection from objects with a thickness of 1 mm (most wires).
— 5. Complete protection from contact of the “internals” with foreign objects, resistance to dust (it can penetrate inside the case, but in scanty quantities that do not affect the operation of the device).
— 6. Completely closed housing, preventing dust from getting inside.
The second digit in the IP marking characterizes the degree of protection against moisture:
— 0. Complete absence of any protection; water ingress into the housing is not allowed.
— 1. Protection from vertical drops of water.
— 2. Protection against vertical drops when the body is tilted up to 15° from the standard position.
— 3. Protection against splashes falling on the body at an angle of up to 60° to the horizontal, the minimum indicator that allows us to talk about resistance to rain.
- 4. Protection against splashes from any direction, allows you to safely withstand rain and strong winds.
— 5. Protection from water jets from any...direction, resistance to storms.
— 6. Protection from strong water jets or strong sea waves (when the device can be completely hidden under the wave for a short time).
— 7. Possibility of short-term immersion to a depth of up to 1 m (without the possibility of constant operation in submerged mode).
— 8. possibility of long-term immersion to a depth of more than 1 m (with the possibility of constant operation in submerged mode).
The degree of IP protection is especially important to consider when choosing outdoor models - they are the ones most susceptible to adverse environmental influences. This parameter is also important when placing the inverter in rooms with high humidity levels.
Operating temperature
The range of ambient temperatures in which the solar panel inverter is guaranteed to maintain normal operation. Here it is necessary to focus on the expected minimums and maximums of temperatures. Moreover, for operation in the cold season, it is worth paying close attention to models with the ability
to operate at sub-zero temperatures.