Guides · Faisalabad, Lahore, Punjab
How to Read a Solar Inverter Datasheet
Short answer
A solar inverter datasheet tells you four things: how much panel power and voltage the inverter can safely accept (the DC input section), how much power it can deliver to your home and for how long (the AC output and backup section), which batteries it can work with (the battery section), and how well it copes with heat, dust and faults (efficiency, protection and general data). The kW figure on the box is only one line of it. The other lines decide whether the inverter suits your panels, your battery, your connection and your roof.
This guide walks through a typical datasheet section by section, in plain language. It is not about any one brand; field names vary slightly between makers, but the ideas are the same.
Why the datasheet matters more than the label
Two inverters both sold as "10 kW" can behave very differently:
- one may accept long strings of panels and the other only short ones;
- one may handle the starting surge of an AC or water motor and the other may trip;
- one may take a 48 V battery and the other only a high-voltage battery stack;
- one may be built for an outdoor wall and the other only for a cool indoor room.
The datasheet is where these differences are written down. When you compare quotations, ask for the datasheet of every inverter model named. Our guide on comparing solar quotations explains what else to ask for.
Reading an inverter datasheet
PV input
Max DC, MPPT range, strings
Battery
Voltage range, charge current
AC output
Rated, backup and surge
An example datasheet, in plain English
The table below uses round illustrative numbers for an imaginary 10 kW hybrid inverter. It is not any real product. Use it to learn what each line means, then check the real datasheet of the model you are quoted.
| Datasheet line | Example value (illustrative) | What it means for you |
|---|---|---|
| Max. DC input voltage | 1,000 V | No string may ever exceed this, even on a cold winter morning |
| MPPT operating voltage range | 150 to 850 V | Strings must sit inside this window to produce full power |
| Start-up voltage | 160 V | Below this, the inverter will not wake up in the morning |
| Rated input voltage | 600 V | The voltage at which the inverter works most efficiently |
| Number of MPPTs | 2 | Two independent inputs, useful for two roof faces |
| Max. input current per MPPT | 16 A | The most current one input can use |
| Max. short-circuit current per MPPT | 22 A | A safety limit the panels' Isc must not exceed |
| Max. recommended PV power | 15 kWp | The most panel capacity the maker allows |
| Rated AC output power | 10 kW | Continuous output to the grid or loads |
| Max. apparent power | 11 kVA | Short headroom above rated output |
| Backup (off-grid) output | 10 kW, with short overload | What can run during load-shedding |
| Battery type and voltage range | Lithium, 40 to 60 V | Which battery class fits (here a 48 V class battery) |
| Max. charge/discharge current | 200 A | Sets how fast the battery can charge and supply load |
| Max. efficiency | 97.5% | Best-case conversion efficiency |
| Weighted efficiency | 96.5% | A more realistic average efficiency |
| Ingress protection | IP65 | Dust-tight and protected against water jets |
| Operating temperature | −25 to +60°C, derating above 45°C | Output reduces as the inverter gets hot |
Now let us take each section in turn.
Section 1: DC input (the panel side)
This section decides how many solar panels (solar plates) you can connect and how they must be wired.
Maximum DC input voltage
This is the hard limit. Panel voltages add up in a series string, and panel voltage rises in cold weather. A string that is safe at noon in June can exceed the limit on a clear January morning in Punjab. Exceeding it can destroy the inverter and void its warranty. An engineer works out the cold-weather string voltage from the panel datasheet's open-circuit voltage (Voc) and temperature coefficient. Our series vs parallel wiring guide shows how strings are built.
MPPT voltage range and start-up voltage
The MPPT (maximum power point tracker) is the part of the inverter that keeps squeezing the most power out of the panels. It only works fully when the string voltage sits inside its operating range.
- If a string is too short, its voltage on a hot afternoon may drop below the range, and output suffers. Panel voltage falls as panels heat up; see solar panels in Punjab summer heat.
- The start-up voltage is the minimum at which the inverter switches on. A string just above it starts late in the morning and stops early in the evening.
Number of MPPTs and current per MPPT
Each MPPT is an independent input. Two MPPTs let you put a string on an east-facing roof and another on a west-facing roof without one dragging the other down. The maximum input current per MPPT matters with today's large panels, which have high current. If a panel's operating current is above the MPPT limit, some power is lost; if its short-circuit current is above the inverter's short-circuit limit, the combination should not be used at all.
Maximum PV power
Many makers state how much panel capacity they allow per model. Connecting somewhat more panel kW than inverter kW is normal and is explained in our inverter DC/AC ratio guide. Staying within the maker's stated maximum protects your warranty.
Section 2: AC output and backup
Rated power and maximum apparent power
Rated output power (in kW) is what the inverter can deliver continuously. Maximum apparent power (in kVA) is a little higher and covers short periods and loads with a poor power factor. Do not size your loads to the maximum; size them to the rated figure.
Phase and voltage
The output line shows single-phase (for example 230 V) or three-phase (for example 400 V). This must match your connection. A single-phase inverter on a three-phase meter only supplies one phase. Read three-phase vs single-phase inverters before choosing.
Backup output and surge
On a hybrid inverter, look for a separate backup, EPS or off-grid output line. It can be lower than the on-grid rating, and some models need an extra backup box to supply loads during an outage.
The surge or overload rating tells you how much more than rated power the inverter can supply, and for how long, for example "150% for 10 seconds". This matters for motors, water pumps and non-inverter ACs, which draw a short spike when they start. Our guide to inverter AC vs non-inverter AC on solar explains starting surge in more detail.
Section 3: Battery (hybrid inverters only)
This is the section most often ignored, and the one that causes the most expensive mistakes.
- Battery voltage range. A range around 40 to 60 V means a low-voltage, 48 V class battery. A range of several hundred volts means a high-voltage stacked battery. The two are not interchangeable. See high-voltage vs low-voltage solar batteries.
- Battery type. Lithium (LiFePO4) only, or lithium and lead-acid.
- Maximum charge and discharge current or power. This limits how quickly the battery refills from solar and how much load it can carry at night.
- Communication. Most lithium batteries need to "talk" to the inverter through a CAN or RS485 link. The maker usually publishes a battery compatibility list; a battery not on it may work poorly or not at all.
Section 4: Efficiency
Maximum efficiency is the best figure the inverter reaches under ideal conditions. A weighted efficiency (often called European or CEC efficiency) averages performance across different power levels, so it is closer to real life. Modern inverters from reputable makers generally score high on both. A difference of a fraction of a percent between two good inverters matters less than correct string design, shading and heat.
Section 5: Protection and general data
Protection features
Expect a list such as anti-islanding (the inverter stops exporting when the grid fails, to protect line workers), DC reverse polarity protection, insulation monitoring, residual current monitoring, and AC and DC surge protection. Some models add arc-fault detection. Built-in protection does not replace external DC and AC breakers, earthing and surge devices.
IP rating, temperature and cooling
The IP rating shows protection against dust and water. IP65 or IP66 suits a sheltered outdoor wall; a lower rating means indoors only. Our guide on where to install your inverter and battery explains the codes.
The operating temperature range often comes with a note on derating: above a certain temperature, the inverter reduces its output to protect itself. In a Punjab summer, an inverter in direct sun or a closed room will derate, so placement matters as much as the number on the sheet. Also check the cooling method (natural convection or fans), the weight and the dimensions.
Monitoring and certificates
The communication line tells you how monitoring works (Wi-Fi, Ethernet or a 4G dongle). The certificates line lists the safety and grid standards the maker says the model meets. We do not interpret those for you as an approval in Pakistan; your DISCO's own requirements apply.
A quick checklist when you compare datasheets
- Does the AC output phase match your connection?
- Will your planned strings stay below the maximum DC voltage in winter and above the MPPT minimum in summer?
- Do the panels' current figures fit within the per-MPPT limits?
- Is the total panel kW within the maker's stated maximum?
- Does the backup rating, with its surge figure, cover the loads you need in load-shedding?
- Is your chosen battery on the compatibility list, at the right voltage?
- Does the IP rating and temperature range suit where it will be mounted?
The panel side of the same exercise is covered in how to read a solar panel datasheet, and unfamiliar terms are in our solar glossary.
How Solar Works Pakistan uses datasheets
Our in-house engineers check each inverter's datasheet against the actual panels, battery, connection and mounting spot before a quotation is issued. The quotation then names the exact brand and model, so you can read the same datasheet yourself. We supply inverters from Huawei, Sungrow, Solis, GoodWe, Knox, Luminey, Inverex and Primax; see our brands page and the solar inverter price in Pakistan list. Each inverter carries its manufacturer's warranty per product, and our installations add a 1-year service warranty under the applicable project terms.
Get today's price or a free site survey
Send us the datasheet you have been quoted, or your bills and a few roof photos, and our engineers will tell you plainly whether the inverter fits.
- WhatsApp or call: 0336 666 4321
- Email: info@solarworks.pk
- Head office: Main Boulevard, Sargodha Rd, Block F FDA City, Faisalabad
- Lahore branch: 2nd Floor, Jeff Heights, Gulberg, Lahore
- Hours: 9:00 AM to 6:00 PM daily
We serve customers throughout Punjab. See our Faisalabad and Lahore pages, or contact us.
Frequently asked questions
What is the most important line on a solar inverter datasheet?
There is no single line, but the maximum DC input voltage is the one that can destroy an inverter if ignored. After that, check the output phase, the MPPT range and, on a hybrid, the battery voltage range.
What is the MPPT voltage range?
It is the band of string voltages within which the inverter can track the panels' best operating point. Strings should stay inside it on both hot afternoons and cold mornings, which is why string length is set by calculation, not guesswork.
What does start-up voltage mean on an inverter?
It is the minimum panel voltage at which the inverter switches on. A string that sits just above it will start late and stop early each day, so designers keep strings comfortably above it.
What is the difference between maximum and weighted efficiency?
Maximum efficiency is the best result under ideal conditions. Weighted efficiency averages performance across different load levels and is a better guide to everyday operation.
Can I connect any battery to my hybrid inverter?
No. The battery must match the inverter's voltage range and type, and should be on the inverter maker's compatibility list so the two can communicate. Check this before buying either.
What does inverter derating mean?
When an inverter gets too hot, it reduces its output to protect itself. The datasheet shows the temperature at which this starts. Shaded, ventilated mounting reduces derating in Punjab summers.
Does a higher IP rating mean I can install the inverter in the sun?
No. IP65 or IP66 means the casing resists dust and water. It does not protect against heat, and direct sun increases derating and ageing.
Sources
- Huawei, SUN2000-5-12K-MAP0 specifications page (example of how a maker groups datasheet fields; consulted for field names only, figures in this article are illustrative)
- Solis, S6-EH1P(3-10)K-L-PLUS product page (example of low-voltage battery range, per-MPPT current and overload fields)