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Fronius CL Inverters

The Fronius CL for commercial solar systems combines high-yield power electronics with the unique, modular system design of up to 15 identical power stages in the MIX™ concept. This makes Fronius CL inverters the optimal central inverter for commercial solar systems of up to several hundred kilowatts. Other features include the exact MPP tracking of the module manager, the automatic transformer switching function and much more. This makes the Fronius CL a distinctive multi-featured device that guarantees continual high solar system performance.

Fronius CL InvertersUp to 15 identical power stages in the Fronius CL inverter create a compartmentalized system.

This concept was developed to ensure the highest stability in large multi-kilowatt commercial solar systems.


Fronius CL Inverter Review

Proven reliability.
The Fronius solar technology, the MIX™ Concept with the Fronius Module Manager, creates a compartmentalized system by integrating several smaller power stages. If one power stage should fail, all others operate normally and loss is mitigated due to strict isolation of the problem. In comparison: when the power stage fails in PV systems with a single stage inverter, the entire system stops operating and this leads to considerable loss of earnings. The Fronius MIX™ concept ensures that the inverter remains in operation even when there is a defect in a power stages and this helps to lock in your earnings.

CL Power Stage in Rack
Installation made easy: The power stages can be easily removed from the PowerRack for transport. Cables with large cross sections can be easily connected in the spacious connection area.

Simple planning, easy installation.
The Fronius CL was designed with practicality in mind. It can be used for many different configurations due to its planning flexibility. It is also easy to set up due to numerous design details that make installation and connection as simple as possible.

Long service life.
The control unit automatically calculates which power stages and how many will be turned on and off in partial load operation based upon the respective operating hours of the power stages. This helps to equalize the work load on the electronics. This also decreases the operating hours of the individual power stages thus increasing the service life of the inverter.

Fast service option.
When service is required, power stages can be easily removed and replaced via the plug & play principle and drawer design. This ensures the highest serviceability and the fastest reaction times on the market.

Generous connection area.
Sufficient space is available for connections and cabling with large cable cross sections, making installation much easier.

High-yield power electronics.
The Fronius CL was designed for continual high performance. The clever combination of automatic transformer switching, the precise Fronius Module Manager, the innovative ventilation concept and the advantages of the high frequency transformer technology make it one of the highest yield inverters of its class.

Power StageHigh performance power stages with uniform high efficiency using automatic transformer switching, precise MPP tracking and an intelligent cooling concept.

Automatic transformer switching.
Fronius transformer inverters use a high-frequency (HF) transformer. The Fronius CL provides constant, high efficiency over the entire input voltage range. This is because Fronius inverters have three efficiency peaks due to automatic transformer switching. The result: A constant level of efficiency across the entire input voltage range, resulting in higher yields. In comparison: Devices without transformer switching only have one efficiency peak. The efficiency then decreases steadily with an increasing input voltage. Other key advantages of HF transformer technology are a compact, lightweight design, and safety as a result of the galvanic isolation.

Exact MPP tracking.
The Fronius Module Manager always finds the exact maximum power point (MPP). This is true even with the more demanding thin film modules. Overall, the Fronius Module Manager is able to achieve an outstanding MPP adaptation efficiency of 99.9 %. This ensures that the maximum yield is obtained from every ray of light.

High-frequency transformer technology.
High performance with low weight and a compact design: The use of proven high-frequency transformer technology produces excellent performance results. The Fronius CL uses galvanic isolation, which meets the strictest safety standards worldwide.

MIX Technology
The Fronius MIX concept: Maximum effciency even during rain, cloudiness or at dusk. The power stages turn on or off depending on the irradiance, ensuring maximum earnings.

Unique system design with the Fronius MIX™ concept
Up to 15 power stages operate in the Fronius CL accomplishing something great together. This combination of several power stages has many advantages: maximum earnings in partial load ranges, high system stability, long service life, and easy servicing. Higher partial load efficiency. 9, 12 or 15 identical power stages divide up the work in the MIX™ concept. The individual power stages are turned off and on automatically depending on the irradiance. This ensures that the load is optimized and yield is always at maximum – even while raining, when cloudy, or at dusk.

Intelligent cooling.
An innovative ventilation design eliminates dust and moisture from getting into the power stage area. The air required for cooling is drawn in by two fans on the front of the device and passed through a closed channel through the individual power stages. The electronic components never come into contact with the outside air. Inside the airtight power stage, a smaller fan ensures uniform cooling. This sophisticated system increases the operational reliability and the service life of the inverter.

Wide input voltage range.
Different module configurations are possible: The wide input voltage range ensures high flexibility for system configuration. Integrated grounding option. The Fronius CL is compatible with either positive or negative grounded modules. Simply change two wires and a software parameter to change from negative to positive grounding. Optional exhaust air guide. If the Fronius CL is set up in a closed area, the exhaust air can be channeled out of the space using a connected pipe to prevent extreme heating of the ambient air. An integrated relay contact can also be used to control an external fan that draws the air to the outside.

Low installation height.
The Fronius CL can also fit into confined spaces due to its low 72 inch height (with base). This compact design is achieved by its three-column arrangement of power stages in the inverter.

Low installation weight.
The power stages can simply be removed for installation. This reduces the weight of the Fronius CL and makes the housing easier to move. The power stages can then be re-inserted and the inverter can begin operation immediately.

Optional exhaust air guide.
If the Fronius CL is set up in a closed area, the exhaust air can be channeled out of the space using a connected pipe to prevent extreme heating of the ambient air. An integrated relay contact can also be used to control an external fan that draws the air to the outside.


Datalogging & Monitoring Options

Monitoring using Signal Card

• Monitoring using Personal Display
• Monitoring with Fronius CL DatCom

Additional components

• Fronius CL Public Display
• RiCo Display with Public Display Card
• Sensors with Sensor Card

Combination of components

• Public Display + Sensor Box
• Public Display + Sensor Box + FRONIUS SolarWeb + Fronius CL.message
• String Control (ideal for Fronius CL central inverters)
• String Control + Basis DatCom

info Fronius Datamanager Datasheet

Extensive system monitoring
System monitoring is vital for inverters of this size. Using the comprehensive Fronius DATCOM system, you can set up a complete monitoring system including extensive data recording, analysis, visualization as well as remote monitoring.

100 % DATCOM-compatible.
The Fronius CL can utilize all options for professional system monitoring within the comprehensive Fronius DATCOM system. The Fronius Com Card is already integrated. Other components such as the Datalogger, sensors and much more can be added at any time. Therefore, it can be equipped for any situation.

Integrated Com Card.
The Fronius CL has two DATCOM option slots. One of which comes standard with a Fronius Com Card. Therefore, a professional monitoring system can be installed right away.

Integrated Interface Card function.
An open data protocol is used to read system data enabling you to easily use third-party components for system monitoring.

Fronius string controlThe Fronius String Control 250/25 continually compares the string currents of up to 25 module strings. This enables you to quickly detect and localize problems within the entire system.

Fronius String Control 250/25.
The customized solution for string monitoring. The Fronius String Control 250/25 continually compares the string currents of connected strings with each other. This enables the early detection and localization of problems in the entire system (e.g. gnawing damage to cables from small animals, module failure, etc.). This can prevent an incremental loss of earnings. Up to 25 module strings can be fused and bundled using the Fronius String Control 250/25.

Fronius solar know-how is built into every CL inverter. They are built to last by a company that has been around long enough to know.

Fronius configuration tool
The Fronius configuration tool is safe, easy and just requires a common Internet browser.

Fronius Configuration Tool

Comprehensive & User Friendly - For the perfect sizing of your PV system.
In the planning stage of a PV system, the Fronius Configuration Tool supports you in the best possible way to get the perfect sizing. Just complete the input fields and you will quickly get charts of the different configuration possibilities. Solar Electric Supply has been designing solar inverter systems for over 15 years. Contact our knowledgeable staff with any other questions you may have about solar system design.

System Requirement for using Fronius Configuration Tool
Internet browser: Firefox, Chrome or Microsoft Internet Explorer 6.0 equivalent or newer.
Download configuration tool

Disclaimer:  The Fronius Configuration Tool was developed by Fronius to assist Users with system designs but does not guarantee the configuration is appropriate for your use. By using the Fronius Configuration Tool, the User claims all responsibility for the accuracy and validity of the results including, but not limited to, system design, performance, and code compliance. It is incumbent upon the User to verify that the system design will meet their site-specific needs and local codes. 


Solar Electric Supply, Inc. is an Authorized Fronius Solar Inverter Dealer


Call toll-free (877) 297-0014 for wholesale Fronius CL inverter pricing and complete systems.