General Questions

What is the APsystems microinverter?

The APsystems Microinverter converts the power output of a solar module from direct current (DC) to alternating current (AC), maximizing the electric power output of each module in a solar array. Unlike a conventional “string” inverter (which runs the output of many solar modules through a single inverter), the APsystems Microinverter allows each module in the solar array to perform independently, optimizing the whole system’s power output.

What is the APsystems microinverter solution?

The APsystems microinverter solution has three key components:

  • The APsystems microinverter performs DC to AC power conversion for individual PV modules.
  • The APsystems Communicator (Energy Communication Unit, or ECU) collects module performance data and sends it to an internet database.
  • The APsystems Monitor (Energy Monitoring and Analysis, or EMA) software allows around-the-clock management of the solar array through any web-enabled device, like a home computer or smartphone.

Because it is an integrated system, the APsystems microinverter solution maximizes the system’s solar energy harvest; increases system reliability; simplifies PV system design, installation, maintenance and management; and improves installer and owner safety.

The APsystems microinverter will operate in standalone mode without connecting to either the APsystems Communicator or the APsystems Monitor, and also works with the APsystems Communicator alone. To allow full web analysis, the APsystems Communicator must be connected to and logged into the APsystems Monitor.

Why choose APsystems microinverters over regular “string” inverters?

As the name implies, a conventional “string” inverter is attached to a row of solar panels (modules) with the inverter placed at the end of this string. The inverter manages current from all solar modules as a single unit, based on the performance of the lowest-performing module. That means if a leaf falls onto one module, the output of all other modules is reduced to the same compromised level. That’s a system built for inefficiency! Also, string inverters must typically be replaced twice over the array’s lifetime, adding significant cost.

APsystems microinverters are the smarter choice – working with individual modules to always optimize the performance of your solar array.

With APsystems microinverters, any problems with shade or solar module inefficiency are restricted to that single unit and are not expanded over the whole array. All the other modules in your array will continue to operate at full power, greatly increasing the productivity and performance of your entire system.

Built into each APsystems microinverter is a function called Maximum Power Point Tracking. Working at hundreds of times per second, the microinverter continually finds the greatest possible module power, optimizing total output.

APsystems microinverter installations are typically 5-15 percent more efficient than comparable “string” systems. That’s like having more solar modules on your roof with the same-sized array.
When combined with the APsystems Communicator and APsystems Monitor, the APsystems microinverter lets you track the performance of each module in your array, while the installer can also remotely troubleshoot any issues that may occur.

Where can I install an APsystems microinverter? Can I add more solar modules in the future?

The compact, independent design of APsystems Microinverters allows for easy installation on virtually any available surface, without needing to adjust for uncontrollable shading effects. You’ll have the flexibility to expand your solar array at any time, hassle-free combining different orientations on the same roof without impacting your solar production .

Is the APsystems microinverter safe?

APsystems microinverters tie directly to the low-voltage PV module and connect to the public power grid via standard AC voltages. This enhances worker and homeowner safety and eliminates the possibility of high-voltage DC “arc” fires.

Is APsystems microinverter technology dependable? What about a warranty?

All APsystems products undergo rigorous factory testing, evaluation, and field tracking, giving you the highest quality, most dependable solar solution. The APsystems microinverter is designed to operate under even the most stressful environmental conditions for a twenty-five year lifespan, to match the lifetime of your solar module.

Each unit carries a full replacement 10 year limited warranty, and the end user can purchase an additional 10 year Extended Limited Warranty to provide coverage for a full 20 years.

As the industry leader in solar microinverter technology, APsystems is proud to stand behind our products.

May an APsystems microinverter be directly connected via a plug to a wall outlet?

No, according to the International Low Voltage Regulations, the direct connection of a single micro-inverter is not permitted via a plug in a socket and should be connected to the AC distribution panel

Do you have a Return Merchandize Authorization (RMA) Process

Yes, the Return Merchandize Authorization (RMA) Process is available here

What is APsystems ECU?

ECU is the acronym for “Energy Communication Unit”. It is used to monitor the production of energy and other data from the installations’ microinverters. It will then post them on the Energy Monitoring and Analysis (EMA) website. Connect to this website via the Internet or the EMA application for a real-time view or history.

Which ECU corresponds to which microinverter?

  • ECU-3 (no longer available): YC500
  • ECU-3Z (no longer available): YC1000
  • ÉCU-R : YC600, QS1, YC1000
  • ECU-C PLC: (no longer available): YC500
  • ECU-C ZigBee : YC600, QS1, YC1000

Can the APsystems Microinverters work without the ECU ?

Yes, the installation of an ECU is not required when using APsystems microinverters but as the ECU registers the daily energy production, it brings you the capability to benefit from a per-module monitoring. Furthermore the ECU can be used for re-configuration and remote diagnostics lowering maintenance costs and enhancing the relationships with your customers.

An USB connection is available on the ECU. May I connect a PC to this USB port?

No, the USB port is only intended to be a reserved port.

How do I contact the APsystems Technical Support?

Contacting the Technical Support APsystems may by sending an email to support.emea@APsystems.com or by phoning +31 (0) 10-2582670 or +33 (0) 4 81 65 60 40.

What is APsystems EMA?

EMA is the acronym for “Energy Monitoring and Analysis”. This is the monitoring database for solar installations using APsystems micro inverters monitored by an APsystems ECU.

– You need an EMA end-user account to view your energy data in real time or in summary form. To obtain it, you must contact your installer.

– As an installer, you need an EMA installer account to register system owners. To obtain it, you must contact APsystems technical support.


Where can I get the EMA application (EMAAPP) dedicated to end-users ?

You will find the QR code for both applications, for Android or IOS smartphones when you click on “EMA login” in the upper right corner. Look for “EMAAPP” in ITunes or Google Play.

Is it possible to obtain an EMA account for one end-user for several ECUs?

Yes, it also works with different types of computers and inverters, and different locations.

Is it possible through 1 single ECU, to get multiple end-user accounts (Master and sub-users)?

Yes, APsystems developed an advanced feature within the EMA dedicated to multi-residential applications. This function called “ECU Share” enables for each end-user to view their own PV production (sub-user account) while the site manager (master account) will get and aggregated view of all related systems producing in a very cost-efficient way, using only 1 ECU.


Technical Questions

How many PV modules can I connect to a microinverter?

– YC500, YC600 : 1 or 2

– QS1, YC1000 : 1,2,3 or 4

Can I connect different types of PV modules using various orientations on the same microinverter?

Yes it works with the YC500, the YC600 and the QS1.

If I connect fewer PV modules than the maximum number that a microinverter can handle, can I use more powerful PV modules than recommended?

In most of the case No. It can only work with YC1000 (360Wp max instead of 310Wp if 3 PV modules are connected instead of 4).

What recommended PV modules power range works with our microinverters?

We recommend PV modules:

– up to 310Wp for YC500 and YC1000,

– up to 360Wp for the YC1000 if only 3 PV modules are connected,

– up to 365Wp for YC600 and QS1.

Which PV modules are compatible with APsystems microinverters?

Generally 60 and 72 Monocrystalline or Polycrystalline  cell PV modules, please send us the module datasheet for approval.

What is the LED status of my microinverter(s)?

  • The LED flashes red every 10 seconds: the inverter is connected to PV modules (at least one) but does not produce any energy.
  • The LED flashes green every 2 seconds: the inverter produces but does not communicate with a computer.
  • The LED flashes green every 10 seconds: the inverter produces and communicates with a computer.
  • The LED is fixed red: the inverter has detected a fault or is defective.
  • The LED is off: the polarity of the +/- module is incorrect or the inverter is defective.


Is earthing required to install APsystems micro-inverters?

Grounding of the PV system is done by mounting the micro-inverters on the PV-metal frame. If no metal PV frame is used, the micro-inverters are to be grounded separately, using  a separate ground wire.

May an APsystems microinverter be directly connected via a plug to a wall outlet?

No, according to the International Low Voltage Regulations, the direct connection of a single micro-inverter is not permitted via a plug in a socket and should be connected to the AC distribution panel

Do APsystems Microinverters have an internal galvanic isolation?

Yes, APsystems micro-inverters have an incorporated High Frequency Transformer avoiding the need to add an Earth Leakage circuit Breaker in most configuration.

How many inverter units can I connect per 20 A branch?

–  7  YC500 units

–  7  YC600 units

–  3 QS1 units

–  12 YC1000 units

Can I mix and match several microinverters on the same 20 A branch?

Yes,  our new range of multi-module microinverters ie. YC600 and QS1 are compatible with each other. They use the same AC cables and accessories.

What DC connectors type do you use on your microinverters range?

All APsystems microinverters are equipped with MC4 DC connectors.

Is the micro-inverter providing 230V output when a PV module is connected and the system not yet connected to the main grid?

No. The Anti-Islanding ‘security is mandatory! When electrical grid is switched off, all microinverters outputs are cut off .

Only when the inverter is plugged in to the main grid, the PV system produces energy. After connecting, it will first test the grid voltage, frequency and impedance before the inverter switches on.

Is it possible avoid any power reinjection to the grid using APsystems microinverters solution?

Yes, it is. To do so, you need the ECU-C with CTs (Current Transducers provided by APsystems) with the current microinverters offer (YC600, QS1 & YC1000). Please refer to our library section on the website.

Can I power electrical equipment’s when I have extra power available from PV?

Yes. To do so, you need the ECU-C with CTs (Current Transducers provided by APsystems) with the current microinverters offer (YC600 & QS1 in single-phase systems only).

This function allows ECU-C through Relay Output port #2 (R2N,R2L) to power a load with an external contactor when extra production from PV is available, the value of extra power (PV production – load consumption) is adjustable (Power Limit in ECU-C local interface). For further details, please refer to our library section on the website

Should APsystems Microinverters be configured to start working?

APsystems Microinverters are pre-configured in compliance with local electrical grid requirements and will start working as soon as they are connected to the AC network. They can work autonomously without the need to connect an ECU.

Does the ECU automatically detect APsystems Microinverters on an installation?

The ECU must 1st, be pre-configured (ie. enter microinverters UIDs) to detect the microinverters on the field. This operation can be done remotely ( local connection). It is important not to forget this step which can be done before or during the installation ( Please read the installation manual of the ECU ).


What is the default IP address of the ECU?

The default IP addresses (internal)  are :

  • for the ECU-3V3 is
  • for the ECU-3V4 is
  • for the ECU-C is
  • for the ECU-R is ( no local access through IP address, ECUAPP is needed)

Is there an ECU capable of managing PLC and ZigBee communications?


How many inverters can an ECU manage?

100 units

Why does the EMA display the red system status point?

This means that none of the inverters communicate with the ECU, that the ECU is not connected to the router, or that there is no Internet access.

What is the maximum distance capacity of ZigBee communications?

50m in free field

What problems can I encounter with ZigBee communications?

– have a distance of more than 50m between the ECU and the inverters

– building materials that avoid or block the ZigBee signal (thick wall, metal…)

  • The solution: install the ECU closer to the inverters or use an extension cable for the ZigBee antenna to bring it closer together

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