The CX series are multi-MPPT string inverters from Sungrow designed for three-phase, grid-tied commercial and industrial solar installations. The larger 30 kW – 110 kW units deliver high yield with high conversion efficiencies (98.6% – 98.6%) and feature smart remote monitoring capability.
An essential component of any solar system is an inverter. This device converts the solar modules’ DC power into AC energy for home appliances.
Choosing your solar inverter should be done carefully. The inverter is the solar system’s component that is most subject to failure. Because they have hundreds of sensitive internal components, solar inverters are prone to issues. However, obtaining a quality inverter guarantees top performance for decades.
The Sungrow CX series solar inverters are popular in Australia, but are they the type of high-quality and reliable inverters we’re looking for? This detailed review of the Sungrow CX series solar inverters aims to find out.
We’ll shine the spotlight on these inverters to answer:
- What is the Sugrow CX series inverter?
- How solid are its technical specifications?
- What are its top features?
- How long is its warranty period?
- Is it safe and reliable?
- Can you retrofit it with a battery?
Let’s get into it!
What is the Sungrow CX Series Inverter?
The Sungrow CX series are multi-MPPT string inverters for 1,000 V DC systems.
This string inverter manufactured by Sungrow belongs to the company’s commercial portfolio.
The Chinese-based Sungrow is one of the world’s most bankable inverter brands. The company has been producing inverters for 25 years, and it employs leading solar inverter technologies in its manufacturing process. As some of the company’s best solar inverters, the CX series solar inverters contain several unique features.
Their multi-MPPT technology and innovative PID recovery function allow them to deliver comparatively high yields. The three-phase grid-tied inverters are large (in terms of AC output), providing 30 – 110 kW of solar power.
Sungrow CX Series Solar Inverter Range
Sungrow offers a wide range of string and central inverters. The company’s string inverters are available in 2.5 kW to 250 kW power ranges. However, the CX series used in commercial and industrial solar systems are available in power classes starting from 30 kW.
This review examines five models of the CX series, with a power range between 30 kW and 110 kW:
- SG 30CX,
- SG 33CX,
- SG 40CX,
- SG 50CX, and
- SG 110CX
Sungrow CX Series Technical Specifications
The Sungrow CX Series are some of the best solar inverters you’ll find. The datasheets below reveal incredible input, output, efficiency, and protective elements:
| Model ID | SG 30CX | SG 33CX | SG 40CX | SG 50CX | SG 110CX |
|---|---|---|---|---|---|
| Input (DC) characteristics | |||||
| Max PV Input Voltage: | 1,100 V | 1,100 V | 1,100 V | 1,100 V | 1,100 V |
| Min PV Input Voltage: | 200 V / 250 V | 200 V / 250 V | 200 V / 250 V | 200 V / 250 V | 200 V / 250 V |
| Nominal PV Input Voltage: | 585 V | 585 V | 585 V | 585 V | 585 V |
| MPP Voltage Range: | 200 – 1,000 V | 200 – 1,000 V | 200 – 1,000 V | 200 – 1,000 V | 200 – 1,000 V |
| MPP Voltage Range for Nominal Power: | 550 – 850 V | 550 – 850 V | 550 – 850 V | 550 – 850 V | 550 – 850 V |
| No of Independent MPP Inputs: | 3 | 3 | 4 | 5 | 9 |
| Max Number of PV Strings per MPPT: | 2 | 2 | 2 | 2 | 2 |
| Max PV Input Current: | 78 A | 78 A | 104 A | 130 A | 26 A * 9 |
| Max. DC Short-Circuit Current: | 120 A | 120 A | 160 A | 200 A | 40 A * 9 |
| Output (AC) Characteristics | |||||
| AC Output Power: | 29.9 kVA | 33 kVA @ 45 °C, 400Vac / 36.3 kVA @40 °C, 400Vac 33 kVA @ 50 °C, 415Vac / 36.3 kVA @45 °C, 415Vac | 40 kVA @ 45 °C, 400Vac / 44 kVA @ 40 °C, 400Vac 40 kVA @ 50 °C, 415Vac / 44 kVA @ 45 °C, 415Vac | 50 kVA @ 45 °C, 400Vac / 55 kVA @ 40 °C, 400Vac 50 kVA @ 50 °C, 415Vac / 55 kVA @ 45 °C, 415Vac (Australia: max. 50 kVA) | 110 kVA @ 45 °C, 100 kVA @ 50 °C |
| Max. AC Output Current: | 48.15 A | 55.2 A | 66.9 A | 83.6 A | 158.8 A |
| Nominal AC Voltage: | 3 / N / PE, 230 / 400 V | 3 / N / PE, 230 / 400 V | 3 / N / PE, 230 / 400 V | 3 / N / PE, 230 / 400 V | 3 / N / PE, 400 V |
| AC Voltage Range: | 312 – 528 V | 312 – 528 V | 312 – 528 V | 312 – 528 V | 320 – 460 V |
| Nominal Grid Frequency/ Grid Frequency Range: | 50 Hz / 45 – 55 Hz, 60 Hz / 55 – 65 Hz | 50 Hz / 45 – 55 Hz, 60 Hz / 55 – 65 Hz | 50 Hz / 45 – 55 Hz, 60 Hz / 55 – 65 Hz | 50 Hz / 45 – 55 Hz, 60 Hz / 55 – 65 Hz | 50 Hz / 45 – 55 Hz, 60 Hz / 55 – 65 Hz |
| THD: | < 3% (at nominal power) | < 3% (at nominal power) | < 3% (at nominal power) | < 3% (at nominal power) | < 3% (at nominal power) |
| DC Current Injection: | < 0.5% in | < 0.5% in | < 0.5% in | < 0.5% in | < 0.5% in |
| Power Factor at Nominal Power/ Adjustable Power Factor: | 0.99 / 0.8 leading – 0.8 lagging | 0.99 / 0.8 leading – 0.8 lagging | 0.99 / 0.8 leading – 0.8 lagging | 0.99 / 0.8 leading – 0.8 lagging | 0.99 / 0.8 leading – 0.8 lagging |
| Feed-in Phase/ Connection Phases: | 3/3 | 3/3 | 3/3 | 3/3 | 3/3 |
| Model ID | SG 30CX | SG 33CX | SG 40CX | SG 50CX | SG 110CX |
|---|---|---|---|---|---|
| Efficiency | |||||
| Max. Efficiency / European Efficiency: | 98.6% / 98.3% | 98.6% / 98.3% | 98.6% / 98.3% | 98.7% / 98.4% | 98.7% / 98.5% |
| Protection | |||||
| DC Reverse Connection Protection: | Yes | Yes | Yes | Yes | Yes |
| AC Short Circuit Protection: | Yes | Yes | Yes | Yes | Yes |
| Leakage Current Protection: | Yes | Yes | Yes | Yes | Yes |
| Grid Monitoring: | Yes | Yes | Yes | Yes | Yes |
| Ground Fault Monitoring: | Yes | Yes | Yes | Yes | Yes |
| DC Switch: | Yes | Yes (Not available for Australia) | Yes (Not available for Australia) | Yes (Not available for Australia) | Yes (Not available for Australia) |
| AC Switch: | No | No | No | No | No |
| PV String Monitoring: | Yes | Yes | Yes | Yes | Yes |
| PID Recovery Function: | Yes | Yes | Yes | Yes | Yes |
| Overvoltage Protection: | DC Type I+II/ AC Type II | DC Type II / AC Type II | DC Type II / AC Type II | DC Type II / AC Type II | DC Type II / AC Type II |
| General Data | |||||
| Dimension (W x H x D): | 702 x 595 x 310 mm | 702 x 595 x 310 mm | 782 x 645 x 310 mm | 782 x 645 x 310 mm | 1,051 x 660 x 362.5 mm |
| Weight: | 50 kg | 50 kg | 58 kg | 62 kg | 89 kg |
| Isolation Method: | Transformerless | Transformerless | Transformerless | Transformerless | Transformerless |
| Degree of Protection: | IP66 | IP66 | IP66 | IP66 | IP66 |
| Night Power Consumption: | ≤ 2 W | ≤ 2 W | ≤ 2 W | ≤ 2 W | ≤ 2 W |
| Operating Ambient Temperature Range: | -30 °C to 60 °C (> 45 °C derating) | -30 °C to 60 °C | -30 °C to 60 °C | -30 °C to 60 °C | -30 °C to 60 °C (> 50 °C derating) |
| Cooling Method: | Smart forced air cooling | Smart forced air cooling | Smart forced air cooling | Smart forced air cooling | Smart forced air cooling |
| Display: | LED, Bluetooth + App | LED, Bluetooth + App | LED, Bluetooth + App | LED, Bluetooth + App | LED, Bluetooth + App |
| Communication: | RS485 / Optional: Wi-Fi, Ethernet | RS485 / Optional: Wi-Fi, Ethernet | RS485 / Optional: Wi-Fi, Ethernet | RS485 / Optional: Wi-Fi, Ethernet | RS485 / Optional: Wi-Fi, Ethernet |
| DC Connection Type: | MC4 (max. 6mm2) | MC4 (max. 6mm2) | MC4 (max. 6mm2) | MC4 (max. 6mm2) | MC4 (max. 6mm2) |
| AC Connection Type: | OT or DT terminal (Max. 70 mm2) | OT or DT terminal (Max. 70 mm2) | OT or DT terminal (Max. 70 mm2) | OT or DT terminal (Max. 70 mm2) | OT / DT terminal (Max. 240 mm²) |
Source: Sungrow SG33CX/SG40CX/SG50CX datasheet, Sungrow SG110CX datasheet.
What is the Sungrow CX Series Solar Inverter Output Capacity?
The power range of an inverter series reflects the output capacity. The five models of the Sungrow CX series in this review can produce between 30 kW and 110 kW of AC electricity as follows:
| Sungrow CX Series Model ID | Output Capacity |
|---|---|
| SG 30CX | 29.9 kW |
| SG 33CX | 33 kW |
| SG 40CX | 40 kW |
| SG 50CX | 50 kW |
| SG 110CX | 110 kW |
The high power ratings of the CX series inverters show that they are not suitable for a home solar system. They are marketed as commercial solar inverters rather than residential solar inverters.
What is the Sungrow CX Series Solar Inverter’s Efficiency?
The CX series inverters have a DC-AC conversion efficiency of 98.6% – 98.7%.
The primary function of solar inverters is to convert direct current coming from the modules to alternating current that is useable by household appliances. Efficiency measures how well the inverter accomplishes this.
Sungrow is the industry leader in terms of inverter efficiency, and the CX series inverters are some of the most productive on the market.
Inverter efficiency ranges from 85% to 95%, with a 90% average. However, the very best solar inverters boast efficiency ratings between 95% to 98%. The CX series inverters trump them all for conversion capability. So, with these inverters, you’ll certainly have more yield than you would with a competing model.
How Many MPP Trackers does the Sungrow CX Series Solar Inverter Have?
The CX Series inverters have 2 to 9 MPP Trackers as follows:
- CX30 – 3 MPPT
- CX33 – 3 MPPT
- CX40 – 4 MPPT
- CX50 – 5 MPPT
- CX110 – 9 MPPT
MPPT is the Maximum Power Point Tracker. An MPPT tracks the optimal power point of a photovoltaic system to maximise the energy available from the modules during its operation.
In the typical operation of a solar power system, modules produce different voltage and current levels, but the system selects the value of the worst-performing module. MPPT solves this problem. Thus, more MPPTs create an increased output.
The SG 30CX Sungrow inverter has two MPPTs, giving it a higher yield than a similarly sized single MPPT inverter. The nine MPPTs of the SG 110CX Sungrow inverter means it has the highest yield of the CX series of inverters.
Does the Sungrow CX Series Solar Inverter have an Internal DC Circuit Breaker?
The Sungrow CX series solar inverters include internal DC circuit breakers.
The internal DC circuit breaker is an essential component of PV systems. Should a short circuit or overcurrent happen, the breaker is the device that blocks the flow to the circuit, thereby preventing electrical damage to the inverter.
However, when buying the Sungrow CX series solar inverters in Australia, only the 30 kW power class features an internal DC circuit breaker.
Sungrow CX Series Solar Inverter Key Features
The CX series solar inverters from Sungrow have some incredible features. These are listed and explained in more detail below:
- High power rating. High output power makes the inverters excellent for commercial applications.
- Compatible with bifacial modules. Working with more efficient bifacial modules generates more output.
- Compact and light enclosures. The smaller footprint and lightweight allow for easy handling and installation.
- Easily accessible connectors. No requirement to open compartments makes installation a breeze.
- Easy commissioning functions. Commissioning is convenient as it is done remotely via Bluetooth or mobile app.
- C5 corrosion resistance. Allows for durable installation even in harsh climates.
- Waterproof enclosure. These protect the inverter components and increase its durability.
- Smart active cooling function. Effecting cooling prevents overheating and long-term damage.
- Good derating behaviour. This coupled with bifacial module enables higher yields.
- PID recovery. Preventing this degradation gives the inverter more longetivity.
- Q Night mode. This saves you the cost of purchasing reactive power solutions.
- Compatible with Al and Cu cables. These are a more affordable option to other cables in the market.
- Up to 1.5 DC-AC ratio. It allows 150% oversizing to provide more energy.
- iSolarCloud. Enables you to comfortably monitor the system.
1. High Power Output
These inverters from Sungrow have solar power output ranges between 30 kW and 110 kW. They are large-size inverters designed for commercial and industrial solar systems (and not for home solar systems). The “CX” in the name of these Sungrow’s series of inverters stands for “Commercial Extreme”.
2. Compatible with Bifacial Solar Panels
The Sungrow CX series solar inverters can be used with monofacial and bifacial modules.
Monofacial modules are conventional modules that use only one side to capture light, while the other side is back-sheeted.Bifacial modules can capture light from both the front and the rear sides. Since it absorbs light converted to solar energy on both sides, bifacial modules generally produce more power.
Compatibility with bifacial modules means that the Sungrow CX series inverters are designed to help you get the best out of your solar modules.
3. Compact and Light
The 30CX and 33CX weigh only 50 kg, while the 40 / 50 / 110CX weigh 58 / 62 / 89 kg respectively. The relatively light weight of the inverters means that you can easily carry them from one place to the other. It also makes installation very straightforward.
In addition to being compact and light, another feature of the inverters which makes installation easy is handling grips.
4. Easily Accessible Connectors
The DC / AC connectors are on the downside of the machine. So, you don’t have to open the enclosure to connect to the ports. The easily accessible connectors make installation simple. Only the 110CX model has its AC terminal closed.
5. Easy Commissioning
After a solar inverter is installed, it will need to be commissioned, which is the process of ensuring that everything works properly. It ‘s rather easy to commission the CX solar inverters, as you can do this via Bluetooth, Wi-Fi, and Ethernet.
6. C5 Corrosion Resistance
The Sungrow CX series inverters fall in the C5 corrosion class. This means that the solar inverter can be installed and operated in harsh environments.
So, whether you are in areas with high pollution rates (such as industrial areas) or areas with high salinity (such as coastal areas), you can operate the Sungrow CX inverters, and they’ll perform regardless of the environment.
7. Waterproof Enclosure
The Ingress Protection rating of the Sungrow CX series string inverter is IP66.
The IP rating shows the degree of protection that an electrical enclosure provides. The IP66 rating of the CX solar inverter means that it offers excellent protection against dust and water.
Some of the best inverters in the market have an Ingress Protection rating of IP65. The IP65 enclosures only protect against low-pressure water jets, while IP66 enclosures protect against strong water jets.
8. Smart Active Cooling Function
The Sungrow CX series inverters have powerful fans for cooling. These are intelligent fans that adjust their speed to ensure that the optimal temperature of the inverters is maintained.
Every 10 degrees of temperature rise cuts the lifetime of electronics in half. But with the smart cooling fans of the CX series, these inverters chill effectively, guaranteeing long-term operations.
9. Good Derating Behaviour
The CX series features lower derating, allowing them to provide a higher yield. Derating is the controlled reduction of inverter power to prevent specific components from overheating. When the permissible temperature of certain parts is reached, the inverters reduce their power output.
The 30 – 50CX inverters begin derating at 45 °C, while the 110CX start derating at 50 °C. Since temperatures rarely reach 45 °C, having your CX inverters in a shaded and ventilated location will guarantee optimum operation without derating.
The CX series will offer you 10% more yield when installed in mild temperatures. Below 40 °C, the maximum power of the 40CX inverter can reach 44 kVA, and the 50CX inverter can reach 55 kVA.
10. PID Recovery
The CX series inverters have a PID (Potential Induced Degradation) recovery function. PID causes significant power loss to inverters due to current leakage between the modules and the module frames.
Previously, installers handled PID by retrofitting third-party devices to a solar power system. But with the Sungrow CX series, there’s no need for this.
The inverters have a PID recovery function that works by adding a high voltage to the modules during non-generating times to restore their yield to normal status.
11. Q Night Mode
The grid often requires reactive power. During the day, a solar system easily meets this requirement as the modules are producing DC power, but at night the DC power drops.
The Q at Night function allows your inverter to meet this requirement for reactive power, even at night. This saves you the hassle of purchasing solutions to provide reactive power at night.
12. Compatible with both Al and Cu Cables
The Sungrow CX series is compatible with aluminium (Al) and Copper (Cu) cables.
Copper was the conductive material used by early experimenters of electricity. Today, it is the material of choice for conducting electricity and is even the international standard.
The use of aluminium for conducting electricity was shunned in the past because the metal has only about 61% of copper’s conductivity. However, aluminium cables are making a return. One reason is that aluminium is lighter – it weighs only about 30% of the weight of copper. Aluminium is also less expensive.
Since the Sungrow CX series inverters are compatible with copper and aluminium cables, you can opt for the inexpensive (yet quality) cable option to save money.
13. Up to 1.5 DC-AC Ratio
The Sungrow CX inverters have a DC-AC ratio of up to 1.5. This means that up to 150% solar oversizing is possible when you use any of these CX series inverters in your solar system.
Solar oversizing means installing modules with a total output capacity greater than your inverter capacity.
It’s wise to pair your inverter with a solar panel system with more capacity. Solar panels are never 100% efficient. Your 5 kW solar panel system won’t be able to produce 5 kW of electricity. Other factors prevent solar modules from making power optimally, such as solar panel degradation and poor weather. Oversizing is the key to higher yield under these conditions.
While most solar inverters allow up to 133% oversizing, the Sungrow CX inverters facilitate up to 150% oversizing (for additional power).
14. iSolarCloud
The Sungrow CX Series solar inverters come standard with the cloud-based monitoring app iSolarCloud.
iSolarCloud allows you to monitor your solar system as it shows you exactly how your system is working. An essential functionality of iSolarCloud is IV curve scanning – an inverter health diagnosis.
The scan will help identify potential failure or risk points in your PV solar system, such as diode short circuit, solar panel mismatch, zero string current, PID attenuation, shadow cover, dust cover, dirt cover, etc.
The convenient one-touch diagnosis does not require any human involvement. It is also very intuitive and can be completed in 15 minutes for a 100 MW solar system.
What is the Sungrow CX Series Solar Inverter’s Warranty?
The Sungrow CX series inverters come with a ten-year product warranty.
Sungrow stands behind its products to guarantee they are free from defects in material and workmanship. The product warranty gives peace of mind because if the inverter becomes defective within ten years, Sungrow is obliged to repair or replace it.
Standard warranties of string inverters usually range from five to ten years. Until 2020, Sungrow’s product warranty was five years. But with many inverter manufacturers offering extended warranties, Sungrow increased theirs to ten years, making it one of the best solar inverter warranties in the Australian market.
However, where you install your solar system does affect the warranty. For example, the fine print states that the warranty period will be limited to two years if the inverter is installed between 2 to 5 kilometres to the coastline.
Is the Sungrow CX Series Solar Inverter Safe and Reliable?
The Sungrow CX series are some of the best solar inverters in the market, so they are undoubtedly safe for use. These inverters have been tested and certified by some of the most reputable bodies in the solar industry.
The inverters are certified by SGS (an international testing, verification, and certification company). The SGS assesses the power quality, grid control capability, protection system, and response during grid faults. The Sungrow CX series inverters have aced these tests to show they are some of the best solar inverters for commercial, industrial, and utility-scale solar farms.
One of the CX series inverters (the 110CX) also received the world’s first DC arc detection and interruption technical report from TÜV SÜD, the German-based world-renowned company for testing, inspection, and certification solutions.
The inverter was tested according to the international standard IEC 63027 ED1 (draft), 82/1636/CDV. It passed the test showing it ticks every box in terms of product reliability and safety. Specifically, it was found that, because of its AFCI function, the Sungrow inverter is better at detecting arcing currents that can cause electrical fires.
Unlike many other inverters and protective devices that cannot detect hazardous low levels of arcing current, the Sungrow inverter uses advanced AFCI electronic technology to sense different arcing conditions, thereby reducing electrical fire hazards.
Is the Sungrow CX Series Solar Inverter CEC-Approved?
The Sungrow CX series inverters are on the list of inverters approved by the CEC (Clean Energy Council).
On the approved inverters page of the CEC website, you’ll find this list of inverters that the CEC has rigorously tested and finds suitable for installation in Australia.
The fact that the CEC approves the Sungrow CX inverters is another endorsement of the inverters’ reliability and safety. The CEC is the regulator of Australia’s solar industry. Its goal is raising standards and maintaining integrity in the industry, and one of the methods it does this is to point buyers to quality modules and inverters.
Also, you can only qualify for solar subsidies when you use CEC-approved inverters. So, using any of these Sungrow CX inverters in your solar power system will make you eligible for small scale technology certificates (STCs).
Can You Retrofit a Battery to the Sungrow CX Series Solar Inverter?
You can retrofit a battery to your solar system with the Sungrow CX series inverter.
Including energy storage in your solar system is wise, as it significantly increases your self-consumption and delivers you more savings.
Using grid power is expensive as electricity rates continue to soar. Also, feed-in tariffs are progressively reducing, so sending excess power to the grid is not as beneficial as it once was.
However, none of the Sungrow CX series inverter models are battery-ready/hybrid inverters. To retrofit a battery storage system to your solar installation, you’ll need to install a second inverter (a battery inverter).
While your Sungrow CX series inverter converts DC power from the panels to AC power for the house, the separate battery inverter converts AC power from the house to DC power to be stored in the battery. You’ll also need to install a metering device, which tells your battery inverter when to store power.
Is this a High-Quality and Valuable Inverter? Our Opinion
The Sungrow CX Series certainly has all the markings of a top-quality solar inverter.
These devices deliver the following:
- Higher yields. They are equipped with multiple power point trackers (3 – 9), allowing them to fully utilise their solar panel arrays. They can be used with bifacial modules to collect light from both sides and produce more electricity. They have a PID recovery function that reduces power losses due to potential induced degradation.
- Smart O&M. The Sungrow inverters use the iSolarCloud app for easy commissioning and remote system diagnosis and upgrade.
- Proven Safety. The inverters have IP66 and C5 protection, so they are effective against dust, water, and corrosion which can affect performance. These devices also comply with all international safety codes.
- Low Cost. They are compatible with Al and Cu cables, so you can use the more cost-effective Al option. The Q Night mode feature of the inverters also saves you the trouble of purchasing reactive power solutions. The inverters are also relatively inexpensive despite being some of the best performers on the Australian market.
Next Steps…
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