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.
This concept was developed to ensure the highest stability in large multi-kilowatt commercial solar
Up to 15 identical power stages in the Fronius CL inverter create a compartmentalized system.
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.
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.
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.
High 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.
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
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.
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.
Datalogging & Monitoring Options
Monitoring using Signal Card
• Monitoring using Personal Display
• Monitoring with Fronius CL DatCom
• 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
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
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 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.
The 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 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
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
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
User to verify that the system design will meet their site-specific needs and local codes.