Professional Installer Frequently Asked Questions
How do I contact APsystems technical support?
Visit your local APsystems website and navigate to the Resources section, then Support. On the Support page you’ll find a form to contact APsystems technical support for your region. They will take a look at the system in question and respond to you shortly.
I need on-site support, when can you be here?
APsystems does not provide on-site support in most circumstances. Installers can contact our support team using the methods described above. Our technical support specialists will provide instructions for addressing and resolving site issues. in fact, most issues can be fixed remotely if the system is monitored with an ECU. If you are an installer currently on-site, call your local APsystems support line for help.
What does the acronym ‘UID’ mean?
The UID (Unique IDentifier) or serial number is a unique 12 digit number assigned to all microinverters.
The inspector is asking what type of DC connectors you use on your products?
APsystems uses the industry standard Multi-Contact (Stäubli) MC4 connectors for all DC inputs.
Can I install different type of APsystems microinverters on the same circuit?
The single phase microinverters (such as DS3, DS3D, YC600B) can be installed in the same circuit. The 3-phase microinverters (such as QT2-MEX, QT2D-MEX) can be installed in the same circuit. Single phase microinvertesr and 3-phase microinverters can’t be installed in the same circuit. Please note for Brazil , since the QT2 has 5 wire cable and QT2D has 3 wire cable, so the 3-phase microinverters for Brazil can’t be mixed
Do you sell a single input inverter, as my installation only has 13 solar panels and I don’t need a dual or a quad?
APsystems is a multi-module input inverter company and does not make a single-module input inverter. If you have an odd number of modules on your installation, simply cap off the unused input with an MC4 dust / sealing cap. Please see the question on “How many solar modules can I connect to each type of microinverter? ”
How many solar modules can I connect to each type of microinverter?
DS3 Series: up to 2 modules ( 2 or 1 modules). it has 2 input channels and per input channel can connect to 1 module. You can leave an input channel empty
DS3D: up to 4 modules ( 4 or 2 modules). It has 2 input channels. And each input channel can have 2 modules connected in series. Please note you can’t only connect to 1 module per input channel, otherwise the voltage is not enough. You can leave one input channel empty.
QT2: up to 4 modules ( 4/3/2/1 module). it has 4 input channels and per inputchannel can connect to 1 module. you can leave any input channel empty.
QT2D: up to 8 modules ( 8, 6, 4, 2 modules). It has 4 input channels and per input channel can have 2 modules connected in series. Please note you can’t only connect to 1 module per input channel, otherwise the voltage is not enough. But yoyu can leave any input channel empty.
Can I connect different sizes, cells, or type of solar modules using various orientations on the same microinverter?
For the input channels that are using the same MPPT, we recommend you to connect to the same modules with the same direction. For the input channels that have independent MTTP, you can connect to different type of modules.
I want to know what type PV mosules can work with APsystems microinverters, do you have a module compatibility calculator?
Yes, APsystems provides module compatibility via our online design guide which can be found by visiting our library.
What is the maximum PV panel power allowed to oversize the power of microinverter?
How many inverters can I connect to each branch circuit?
Please refer to the datasheet and local regulations
Is the microinverter producing power when a PV module is connected but the system is not yet connected to the grid?
No. The microinverter can only produce power when connected to the grid, hence it’s a grid-tied inverter.
May an APsystems microinverter be directly connected via a plug to a wall outlet
This is highly dependent on local regulation (not valid in France, US or Canada).
I noticed that your inverters have an LED status light, what are the different colors and flash sequences?
Is grounding (earthing) required when installing APsystems microinverters?
Apsystems microinverters have ground wire in the cable, and also the washer to be contacted to the mounting systems for the grounding. But some areas do require separate grounding. Please install based on your local electrical regulation or AHJ
Do APsystems microinverters have an internal galvanic insulation?
Yes, a galvanic transformer is embedded in each microinverter.
Do I need to configure APsystems’ inverters to start working?
No need for special configuration, the APsystems inverters will turn on and produce power once it has one or more DC inputs, proper AC, proper frequency and has waited the 300 second dwell time.
What is the peak and nominal AC w output of your inverters
To view specifications, visit our library.
I see a star washer installed on the mounting bracket of my microinverter, what is that used for?
The star washer, or Weeb, is preinstalled and designed to electrically bond the inverter to the rails for grounding. Please check with your local regulations or AHJ for proper grounding for your installation.
Is DC protection required for your microinverters?
Different regions have diffent standards for the DC Arc-Fault protection. Apsystems microinverters have the certificagted of the related countries. For the details of the certificates, please find the Certificate under the Library.
Can I install APsystems’ microinverters in a coastal environment?
Absolutely, APsystems microinverters have been installed in harsh environments, operating normally for more than a decade. We also ensure our designs pass HALT testing which includes; damp heat, humidity freeze, salt mist and UV. Our dual module and quad-module designs have also been independently tested by DNV-GL.
Do the APsystems microinverters have built-in reactive power control to avoid penalties with the utility company?
Both DS3 series and QT2 series are compliant with local regulations regarding RPC
Does APsystems recommend surge protection for the PV array?
Yes, APsystems strongly recommends to install a whole-house surge protection device at the dedicated meter box. Please check with your local regulations or AHJ.
I have an off-grid application, can I use your microinverters?
No, APsystems does not offer an off-grid product at this time. All APsystems products comply with IEEE-1547 anti-islanding standard.
How many MPPTs your microinverters have?
Can Microinverters have 380V output?
Why does the inverter not generate electricity after connecting the components? Will it cause electricity to people when wiring?
What should I do if there is the red light flashing on the microinverter?
Why the LED light of the microinverter doesn’t show any color?
What is the ELS PCS?
The Power Conversion System can also be thought of as a battery inverter. The inverter allows the DC battery to interface with the grid.
What does an APstorage system comprise of?
It comprises of a APsystems Power Conversion System and Compatible DC Batteries. If you are using the ELS-5K, it will also need a Transformer to provide split-phase output during off-grid.
What can I backup when the grid goes down?
The PCS can backup a subpanel that powers 5kW of loads, it can also handle 7.5kW of surge power for 10 seconds. Make sure to also balance 120 loads between L1 and L2 as much as you can, you can do 2.5kW on each phase.
What operating modes does APstorage have?
There are three modes: First is Backup Mode – Priority of the system is to keep the battery as full so that when you lose the grid, you will have maximum energy. Second is Self-consumption Mode – Priority of the system is to limit grid-usage, solar power is used to charge the batteries and power loads. When there’s not enough solar, batteries are used to power loads. Third is Advanced Mode – Off-peak hours and Peak hours are scheduled, during off-peak hours batteries are charged, during peak hours batteries are used to power loads.
Can the user set the operating modes?
Yes with the EMA Mobile App.
What type of batteries should I pair with APstorage PCS?
APsystems does provide our own batteries, but we do work with other battery vendors. This is a compatibility list of batteries we are compatible with. They need to be 40-60V, UL9540a tested, and their BMS is communicated via CAN or RS485.
Can I use solar to charge my batteries when I’m off grid?
Yes, with APsystems DS3 Microinverters at the moment. This is possible by putting the AC output of the DS3 microinverters onto the backup service panel. When the grid goes down, the PCS creates a microgrid that the microinverters will follow and keep solar power on.
How much off-grid solar can I put on the system?
Determine max charge power of the batteries. Then pick the lower number between the battery charge power or the PCS charge power (5kW), multiply that number by 1.25 for the DC-AC ratio, and that is your maximum allowable power you can use for Off-grid Solar. Typically with a ELS-5K with batteries that can do 100A DC of charge, you can put a 20A string as backup power.
What internet connectivity do I need for the APstorage?
You will connect the PCS to your home’s internet either via WiFi or Ethernet, make sure you have connectivity. It is possible to connect the PCS to the internet via a third-party Cellular Router.
How is APstorage connected to the electricity grid?
Our solution is AC-coupled, it only needs to be connected to the Grid on the Main Service Panel.
What are the benefits of an APstorage system?
One is energy resiliency, when the Grid goes down you have batteries to backup the circuits on your backup service panel. The second is energy savings: with the proper mode settings, you can configure your system to limit grid usage and use batteries instead.
How many batteries do I need?
There are two factors to consider when picking how many batteries you want. One is capacity; more batteries means more kWh, which will give you more time. To estimate your time, divide kWh of capacity by kW of power consumed. Another is how much off-grid solar you can charge, more batteries allows you to have more off-grid solar.
Where can I install APstorage at my home?
The PCS is outdoor rated, but it’s best to have a cover to make sure it is protected from the elements. Make sure to read the temperature ratings of all equipment, including the battery you’ve selected and the PCS. The PCS is -13F to 149F, but double check the battery as well. The PCS is installed on the wall and must be done upright.
How much space do I need for APstorage?
Check the clearances requirements on the datasheets, the most up-to-date numbers will be on there.
Will this system work with my already existing PV system?
Yes, when the Grid is on, APstorage will work with any AC-coupled inverter. However, when the grid is down, those inverters will stay off. If you system has DS3s, you can move some of the microinverters into the backup service panel so that they stay on during off-grid, we are looking to expand that offering.
Is this UL9540 Certified?
The ELS-5K is certified to the most up-to-date UL certifications, in particular UL9540. The only batteries we will work with are those that have been UL9540a tested. The APbatteries are LFP batteries, which are the industry-standard of safety for home batteries.
Can I use the ECU-C inside the PCS to manage APsystems Microinverters instead of getting a separate ECU-R?
No, you need to get a separate ECU-R to manage APsystems microinverters on the roof.
Is there an ATS in the PCS? Can it automatically disconnect from the Grid on Grid Loss?
Yes, the PCS will not backfeed power to the main service panel when the grid goes down. The changeover is in the milliseconds range.
How is power measurement done?
The ELS-5K comes with two 80A CTs for production monitoring and two 200A CTs for consumption monitoring.
How do I change my installer-level account password or email address for the EMA?
Visit your local APsystems website and navigate to the Resources section, then Support. On the Support page you’ll find a form to contact APsystems technical support for your region. Make your request on the form or send an email to APsystems support in your region to reset / change username, email address or your login password.
In the EMA, my customer’s system shows 289w on one panel and 281w on another, is there something wrong with the inverter?
No, nothing is wrong with your inverter. The power output of the module is typically +/- 10% from module to module. In addition, the communications ECU / gateway ‘polls’, or asks the inverters for their power production every five minutes one-by-one, and the polling time may differ by a few minutes per solar panel so variations will happen from time-to-time. Shading can also vary module by module.
I see NC (No Communication) on one or more panels in the EMA.
In case of one or more panels is showing NC, a few checks can be done: 1. Make sure the ECU has connected to the power; 2. Make sure the UID of microinverters have been entered to the ECU correctly; 3. Wait for enough time. It takes around 10 minutes. when there are more microinverters, it takes more than 30 minutes; 4. Make sure the light on the microinvertr is green; 5. Make sure the ECU is close to Microinverters. If all of the above doesn’t work, please contact our customer support team.
In the EMA or EMA App, I don’t see power production. Can you help?
Verify that the AC breakers are in the on position, and power is connected all the way to the end of each branch circuit and that panels are clean
My customer is complaining that power production reported on the EMA is different than their utility bill. What is the discrepancy?
The APsystems ECU gateway collects a snapshot of data from each microinverter on the DC side every five minutes and is carefully designed to minimize network traffic and give a most possible accurate production in their operating environment. The utility company utilizes a revenue grade meter which constantly measures power production on the AC side and as such collects data in real-time. The EMA is intended to demonstrate power production, not record revenue grade data. The energy production numbers shown in the EMA are an estimate based on these infrequent intervals and will often be different than those shown in your utility bill for reasons of monitoring frequency, accuracy and what’s being measured (AC vs DC).
What do the EMA traffic lights represent?
Green: The system is functioning normally.
Yellow: It could mean:
1. Some microinverter communication has been interrupted since the beginning of day or…
2. Some microinverters have not been properly registered or…
3. Some microinverters have low power production (abnormal behavior or weak/lack of sunlight)
Consider checking the details of the site in the EMA and verifying microinverter UID registration.
Red: ECU disconnected from internet.
Black/Gray: The system has never reported production data. This system could be offline. If it should be online, verify that the ECU has been installed properly and connected to the internet.
How often does the ECU/EMA collect data from the microinverters?
The ECU ‘polls’ each microinverter every five minutes for a total of twenty polls per hour and data pushed to the EMA portal every 15 minutes.
How do I interpret the ‘Energy Metering’ data I see on the EMA when using the ECU-C?
Green: solar production (always positive)-measured
Grey: grid (positive or negative): imported or exported – measured
Blue: consumption of electrical appliances in the household -calculated (always positive) if the green curve is negative, please reverse the direction of the CT measuring the PV production, if the blue curve is negative, please reverse the direction of the CT measuring the grid import / export
How do I replace an ECU or Microinverter on the EMA?
Simply login to your installer account, navigate to the installation, click on ‘Device Replace’, click on ‘Replace’, enter the new ECU / Microinverter serial number and click ‘Submit’.
The module type shown in the EMA is incorrect. How do I fix the module type for my installation?
See our EMA User guide in our library here.
I have 300W modules on my roof, but I have never seen the module ever produce 300W, is there an issue with my installation?
No problem, module power depends on sun irradiance and module temperature. Click here for more information.
How do I add a new installation to my installed base?
Simply login to your installer account and navigate to the ‘User Registration’ section and follow the self-guided prompts to complete the registration. To view the EMA User Guide, visit our library.
What is the UID of my ECU?
The UID or serial number is located on the back or side of the device and is a 12 digit number starting with a ‘2’.
How to connect the ECU to a wifi network?
Step 1: Switch on the ECU
Step 2: Press the AP button on the ECU
Step 3: Scan the QR code below to download EMA manager if not already done
Step 4: Open EMA manager，click “Local Access” at the bottom right
Step 5: Link to the ECU WIFI with the ECU ID, input 88888888 to log into the ECU；
Note: If the ECU WIFI cannot be found, please try again. Remember to keep the ECU close to the router. The WIFI name is the same as the first UID on the back of the ECU
Step 6: Go back to EMA manager APP, then Click “Workspace” and click “ECU Network”
Step 7: Choose the available router WIFI to link by wireless
When the connection is successful, both lights on the ECU will be green.
My customer recently changed their router or internet provider, how do I reconnect their ECU-R or ECU-C to the internet?
The ECU-R can be connected to the internet via hardwire ethernet cable or Wi-Fi connection. If utilizing the hardwire ethernet cable (the preferred and most reliable method) simply connect the Ethernet port on the ECU-R to an open Ethernet port on the router or switch. If utilizing the built-in Wi-Fi, access the ECU APP and navigate to the Settings tab, WLAN and search for available Wi-Fi, select the homeowner’s router, enter the password and hit OK. See our YouTube video on the ECU-R for instructions on how to do this.
What is the frequency of your Zigbee communication?
The APsystems Zigbee communication works at 2.4GHz, the same frequency as the Wi-Fi in your home or business.
I have set-up and powered on the ECU and there is no communication between the ECU and the microinverters. Why?
Try to position the ECU closer to the microinterters and ensure that the Zigbee antenna is installed properly, the serial numbers of the inverters have been loaded properly and the inverters are compatible with the ECU.
How do I install an ECU-R?
To view installation instructions, visit your regional APsystems website and navigate to Resources > Library. You can also view APsystems installation videos on our YouTube channel.
Will the microinverters be automatically detected by the ECU after connection?
No, the microinverters must be scanned using the ECU APP and synced with the ECU-R/C in order for the microinverters to communicate and demonstrate power production.
I have connected the ECU with an ethernet cable, yet I don’t seem to be connected to the internet?
Please verify that you have plugged in the ethernet port and not the RS485 port of the ECU. Also verify that you are plugged in directly the router and not through a switch or a EOP (Ethernet over Powerline) device. Lastly, you may want to try another ethernet cable, as cables do go bad from time-to-time. [for commercial systems you can utilize the static IP feature using the ECU APP, determined by the IT manager of the business]
How many solar modules can an ECU reliably communicate with and demonsrate power production?
It can connect to max 100 microinverters. We recommend to connect 80 microinverters for the optimized performanced. Try to position the ECU close to the microinverters and try to avoid obstacles or other electrical equipment.
I have a site where the utility will not allow excess power back onto the grid. Do you have a function in the ECU to prevent power reinjection/export?
ECU-C features, such as the “Zero Export” function, can only be used on three phase systems in North America. See our product manual and our installation and configuration guide here.
How do I set-up the Zero Export feature with the ECU-C?
You can learn the step-by-step procedure for utilizing the ‘zero export’ feature of the ECU-C by visiting our library.
I see black lines on the ECU LCD screen, how do I resolve the issue?
Move the screen from direct sunlight, reboot and observe. If that doesn’t fix it, send an email to your local APsystems technical support team for support.
I have an ECU and I see -W or -Web on the screen, what does that mean?
The -W or -Web means that the ECU does not have a proper internet connection. Please reboot the ECU, change the cable or check the internet connection. If this does not fix the issue, please contact your APsystems local technical support team for support.
What is the difference between ECU-R and ECU-C?
The ECU-R is a basic monitoring gateway, while the ECU-C has advanced functions; metering function, zero export and redundant energy control.
I have replaced a defective microinverter, do I need to use EMA Manager APP to enter the new micro in the ECU?
The EMA Manager APP is highly recommended as the scanning feature will ensure accuracy and ease of installation; however, it can be done via the EMA as well if needed.
Can we use Zigbee antenna extensions?
Yes, you can buy extensions from any third-party supplier. Just look for a Wi-Fi antenna, 2.4GHz with SMA male/female connectors. Maximum length of 20m.
Can I use any CTs with an ECU-C?
No, please use the APsystems 80A and 200A CTs. They are available at your local distributor
The location of the main panel and the solar sub panel is longer than the CT leads. How can I extend the CT leads that go to the ECU-C?
APsystems allows up to a maximum of 30 meter extension of the factory CTs using standard CAT 5e cable, which can accommodate up to four CTs per cable.
Can I access an ECU-R in the local area network?
No, there is no local web access to the ECU-R
Can Microinverter systems provide MODBUS protocol?
The ECU can connect to max 100 microinverters. What if I have 101 microinverters? Do I need to have 2 ECUs?
How far from the microinverters can the ECU-R or ECU-C be placed? How far from the site’s wireless router?
How to install CT correctly?
What is the difference between the EMA App and EMA manager App?
The ECU APP is a tool for installers to use in the initial set up of your system. The EMA APP is the monitoring tool system owners will use to monitor their energy production on their smart phone. DIY users can first set up the systems using EMA manager APP, and then use EMA APP for the daisy monitoring.
I want to modifiy my account name, how can I modify it?
I have added an inverter to my existing installation. It looks fine in the EMA Manager App, but I don’t see the new inverter in my EMA APP Account. What should I do?
I want to add energy storage and back-up to a system, what do you recommend?
APsystems inverters are agnostic and will function perfectly with all AC coupled storage solutions on the market today. You can use our APsystems Storage Solution for storage systems.
I want to use a generator to ‘trick’ the inverters into thinking that there is a grid during a power outage, how do I set it up / is that okay?
APsystems’ microinverters are designed to be grid-tied only. APsystems does not support using microinverters in conjunction with a generator on a closed-loop system. The APsystems warranty policy clearly states that microinverters used with a generator are not covered.
How do I responsibly dispose of a faulty inverter or ECU?
Contact your local electronic waste treatment facility.
Please provide the one line drawing for my installation, as the city is asking for plans?
APsystems does not provide electrical drawings or permitting plans for submittal to the utility company.
There is no internet at the site, can the system owner still monitor their power production?
Yes, the ECU has an offline monitor function (traditionally used by installers) that can be used for customers that do not have internet. The offline monitoring feature can be accessed by holding the AP button on the side of the ECU for approximately two seconds and then releasing, connecting your hand phone via the Wi-Fi (ECU-R_216xxxx) broadcast by the ECU and then opening the EMA Manager APP – navigating to the Data tab to see Real Time Data, Power and Energy. (Note about limited memory – check with installer today). Note: APsystems always recommends that the ECU be connected to the internet (hardline or GSM router) to ensure that the ECU and inverters can be updated to the latest software and firmware for the lifetime of the system.
Some string inverters have an outlet on the side of their inverter for use during a power outage, does APsystems have that too?
No, APsystems does not offer that feature and neither do current string inverters due to the updated NEC Rapid Shutdown requirements.
Can you tell me which solar PV design and simulation software(s) APsystems microinverters are available in?
APsystems is featured in many of the popular PV simulation programs today including; HelioScope, PVsyst, PVSol.
Does APsystems have an open API that I can use to program data on my own website/program?
The API is only available for certain installers to develop their applications. The API is a REST API and delivers data in JSON format via HTTPS. The API is categorized into two-level data:
• System Details API
• ECU-level Data API
Access to the API will require unique user credentials provided by APsystems on a case-by-case basis. Contact your APsystems representative for more information.
Current calls are as follows:
• Current Power
• Daily Production
• Monthly Production
• Yearly Production
• Lifetime Production
I have a large wind turbine project and want to use your microinverter, is that possible?
No, the APsystems microinverters are designed to work with today’s solar modules, not wind turbines.