FAQs

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General

What is a microinverter? What is the Enphase Microinverter System?
An inverter is a power converter that converts direct current (DC) into alternating current (AC). Traditionally, this has meant one, centrally-located inverter converts all of the DC current from the entire PV array into grid-compliant AC power. A microinverter is a device that converts the DC output of a single solar module into grid-compliant AC power. AC power then travels upstream through an ordinary branch circuit to the service panel. The Enphase Microinverter System consists of the microinverters as well as the Envoy communications gateway and the Enlighten™ monitoring and analysis system.
What is an Envoy or EMU?
The Envoy (or EMU - Energy Management Unit) is the communications gateway device which relays performance statistics from the microinverters to the Enphase Enlighten website.
What is the difference between an Enphase deployment and a traditional solar deployment?
The Enphase system provides improvements in the following areas:
Productive
  • Per-module MPPT maximizes energy production.
  • Increases resilience to shade, dust and debris.
  • High conversion efficiency.
  • Increased system up-time.
  • Greater production in low-light conditions.
Reliable
  • No single point of failure.
  • Design reduces component stress.
  • Very low internal temperature rise.
  • Designed to NEMA 6P rating.
Smart
  • 24/7 monitoring on a per-module basis.
  • Eliminates concern about where to place a large inverter.
  • Dramatically reduces installation design.
  • Modules can be mismatched and added as your requirements grow.
  • Panels do not need to be collocated.
Safe
  • No high-voltage DC wiring.
  • Reduced risk of DC arc fault.
Can Enphase Microinverters work in off-grid environments?
Enphase Microinverters have only been tested to work in grid-tied installations.
How do Enphase Microinverters differ from PVAC units?
With PVAC, the inverter and module are a single unit and are sold and installed as such. In contrast, the Enphase Microinverter is architected as a standalone inverter. This modular design means that the Enphase Microinverter offers the flexibility to work with most off-the-shelf solar modules.
Can Enphase Microinverters work with other DC power sources such as wind installations?
Enphase Microinverters have only been designed and tested to work in solar PV installations.
Do Enphase Microinverters work in other geographic regions? Do you have plans for a version to support 50 Hz environments?
Enphase products are not currently certified to sell outside North America. We are working toward broader compatibility, so please check our website regularly as we will update our product information as our plans progress.
Is the Enphase Microinverter on the list of inverters authorized by the State of California, eligible for rebate calculations?
Yes. Please visit the following URL for more information:
http://www.consumerenergycenter.org/cgi-bin/eligible_inverters.cgi
Can Enphase be used in both Residential and Commercial solar deployments?
Yes. Enphase Microinverters are designed for 240VAC residential, as well as 208VAC three-phase service.
With which solar modules is the Enphase Microinverter compatible?
Please view the Module Compatibility List for a list of all modules that work with the Enphase Microinverter. The Model M175 240V and Model M175 208V work with 72-cell modules (24V nominal) up to 210-215Wstc. The Model M190 208V and Model M190 240V work with 60- and 72-cell modules up to 230Wstc. The Model M200 208V and Model M200 240V work with 96-cell modules (32V nominal) up to 240Wstc. The model M210 208V and Model M210 240V work with higher voltage 72 cell modules (28V nominal) up to 240Wstc.
Why are SunPower modules not included in the Enphase Compatibility List?
Even though some SunPower modules are electrically compatible with Enphase Microinverters, SunPower has not approved Enphase Microinverters for use with their modules and consequently we are not able to put their PV modules on our compatibility list.
Why did the stated Enphase Microinverter MTBF change from 365 years to 331 years?
The estimate for MTBF on our original design specification was 365 years. As we made changes to the design to meet certification requirements, we found the actual MTBF rating is 331 years. We believe strongly in the importance of metrics to accurately track our reliability and we endeavor to be as open and transparent in our results as possible. Read the Enphase Reliability White Paper.
Where are Enphase products manufactured?
Enphase has partnered with Flextronics, one of the largest contract manufacturers in the world. Flextronics was chosen because they are a global leader with the volume capacity and emphasis on quality that matched our needs. Flextronics has an extensive global network of manufacturing facilities, with the majority of their manufacturing capacity located in regions such as South America, Asia, and Eastern Europe. By keeping the production costs of solar products low, we believe this will lead to wider adoption and more skilled jobs for installers. We further believe that this will enable our installer customers to grow their business more rapidly. Flextronics has an emphasis on quality and adherence to design specifications, a strong commitment to social responsibility, and a stringent code of business conduct and ethics. Further, Enphase has developed custom test equipment and processes in order to ensure every microinverter meets our rigorous product and environmental test standards. This equipment and associated processes have been implemented in each Flextronics manufacturing facility that produces Enphase products.
What is the purpose of the red plastic plug on the microinverter, and what happens if it falls out?
The microinverters are fully encapsulated with a potting material inside the enclosure. This plug is simply there to cover the fill-point for that material. It is not integral to the unit's operation, and will cause no harm if not present.
Is Enphase Energy a public company? What is the stock symbol?
Enphase Energy is a privately-held company. We are not publicly traded and therefore do not have a stock symbol.

Configuration

What PV connectors does Enphase support?
Enphase supports Multi-Contact MC3 connectors referred to as our S01 or S11 (non-locking style) and Multi-Contact MC4 connectors referred to as our S02 or S12 (locking-style). Enphase also supports Tyco Solarlok connectors referred to as our S13 (locking style).
  Multi-Contact MC3 Multi-Contact MC4 Tyco Solarlok
M175 -S01 -S02 N/A
M200 -S01 -S02 N/A
M190 -S11 -S12 -S13
M210 N/A -S12 N/A
How many Enphase Microinverters can be on a single branch circuit?
Following are the maximum Microinverters per branch circuit:
  • M175 - 240V split-phase power - 16 Microinverters per branch circuit
  • M175 - 208V three-phase power - 24 Microinverters per branch circuit
  • M190 - 240V split-phase power - 15 Microinverters per branch circuit
  • M190 - 208V three-phase power - 21 Microinverters per branch circuit
  • M200 - 240V split-phase power - 14 Microinverters per branch circuit
  • M200 - 208V three-phase power - 21 Microinverters per branch circuit
  • M210 - 240V split-phase power - 13 Microinverters per branch circuit
  • M210 - 208V three-phase power - 18 Microinverters per branch circuit
There can be an unlimited number of branch circuits per installation.
How many branch circuits (total) can I have?
The Envoy Communications Gateway (EMU) can currently manage a maximum of 250 microinverters. For systems larger than 250 modules/microinverters, additional Envoy Communications Gateways can be added. If more than one Envoy is used, a Line Communications Filter would be required to contain the communications from one group of 250 microinverters. The maximum number of branch circuits would depend on the model of microinverter chosen. For example: 16 branch circuits with 15 M190-240V microinverters could be supported by a single Envoy gateway.
Do all my modules need to match?
No. One of the advantages of a microinverter system is that it allows for mixing modules. Unlike traditional inverters that are based on a string installation, the Enphase branch circuit approach allows for varying power output levels. This also means that end-user customers have the flexibility of adding or changing modules over time.
Do I need an A/C disconnect on my roof for each Enphase branch-circuit?
This varies by Authority Having Jurisdiction (AHJ).
On a 208v three-phase installation, do I really need all three phase conductors from the service-entrance, or will two suffice?
A three-pole breaker is needed in the load-center, and it is necessary that you pull three phase conductors and a neutral, to the head of each Enphase branch circuit.

Installation

Who performs the installation for the Enphase system?
The Enphase system can be installed by any qualified solar installation company. The microinverter approach makes it easy for system designers to design and install solar deployments.
Can I install an Enphase deployment myself?
Any solar-electric system should be installed by qualified personnel only.
What is the minimum height above the roof that the inverters can be mounted?
We recommend 1" to avoid debris buildup between the roof and the inverter, as well as to allow for heat-dissipation.
What type of junction box is recommended?
We recommend that you use a wet location-rated 2x4 j-box.
What is the correct wiring for the A/C cable assemblies on the Enphase Microinverter System?
The A/C pigtail cable assembly terminates the first microinverter in a branch-circuit to the junction-box. The four conductors' jacket colors in the REV-1 cable for 208v three-phase are Black, Red, Orange and Blue. When terminating the free-conductor end of the cable to the junction-box, connect the cable's BLACK conductor to L1, connect the RED conductor to L2, connect the ORANGE conductor to L3, and connect the BLUE to Neutral. The Neutral line will need to be tagged with a white piece of tape, marking it as the neutral, per the NEC.
Do Enphase Microinverters work with a tracker system?
Yes, Enphase Microinverters work with tracker systems. The only considerations are to ensure that the additional weight of the microinverters does not affect the tracking mechanism's ability to mechanically rotate, that the cables have enough slack, and the grounding wires will accommodate the rotation of the tracker.

Regulatory, Compliance, and Metering

Are Enphase devices UL-approved?
Enphase Microinverters are CSA listed per the requirements of UL1741 and are therefore approved to operate in the United States and Canada.
When I use the CSI EPBB calculator and specify Enphase Microinverters, I get a warning/error message that says: "This inverter requires the addition of a meter/display to qualify for the CSI program. The CSI program requires that all EPBB customers install a ± 5% or better meter. Please refer to section 11 of the CSI Handbook or the California Energy Commission's List of Eligible System Performance Meters." Is Enphase eligible for rebates in the state of California?
Yes, Enphase is indeed qualified equipment for California's CSI EPBB program. The confusion arises because Enphase is the only inverter manufacturer that has a separate meter display (i.e., not built into the inverter itself). Our meter display is the Envoy/EMU. The Enphase meter is a qualified 5% meter, as can be verified by looking at the CSI list of qualified meters. The CSI warning message is simply a reminder that if using Enphase, the Envoy/EMU must *also* be specified. We recommend that you download the Enphase EPBB Meter Letter and submit it along with your CSI paperwork to ensure there is no confusion.
What meters are compatible with the Enphase Microinverter System?
The meter that is known to be compatible is the Energy Tracking Web-Enabled Meter. If you are interested in using another meter, please contact Enphase Customer Support to assess compatibility.
For installations in the State of Hawaii, what is Enphase's position regarding the term "system" for purposes of the Renewable Energy Technologies Income Tax Credit, HRS § 235-12.5?
Enphase has no responsibility or authority to determine the number of "systems" for the purposes of rebate monies. An Enphase branch circuit can contain as few as one microinverter or as many as the maximum number of units per-branch circuit, as defined by that particular model's specifications. The number of units installed on a single branch circuit, protected by a single overcurrent protection device, or constituting a "system" under the terms of this tax-code document, is strictly a matter between the system-owner and the respective tax jurisdiction.

Enlighten™

What do I do if I forget my password to log into the Enlighten website?
Go to the Enlighten portal, and click the link for "Forgot My Password". Enlighten will email you a link to a page where you can select your new password.
How does the microinverter communicate with the Envoy (EMU)?
The microinverters utilize the existing power-line conductors.
How do I get notified when there is an error?
The Enlighten website will send you alerts via email. The volume of email depends on the alert setting that you choose at time of installation.
When can I expect my Enlighten login credentials?
Once Enphase Customer Support has determined that all equipment is operational, and that all historically-produced energy data being relayed to Enlighten is current, login credentials will automatically be issued by Enlighten. This is generally done within 24 hours of initial site activation.
I’m a system owner. How do I grant access to my Enlighten account to others (e.g. my installer, friends or family)?
To control access privileges for your Enlighten account, log in to Enlighten. Click on "Settings" at the top of the screen. Then in "Access" section, grant access to your installer or to the public (this enables access without having to log in, and with limited functionality), and allow your system to be added lists of installations on the web.
How is Enlighten sold and how do I extend my subscription?
All purchases of the Enphase Microinverter System (both residential and commercial) include a 90-day subscription for Enlighten. Subscription extensions are sold at an MSRP of US$2.00 per inverter per year. Subscription extensions may be purchased at the time of initial microinverter purchase or anytime thereafter. Enlighten system owners will be sent email notifications within 30 days of expiration with instructions on how to purchase extensions. System owners may also log in to Enlighten and visit the “Subscription” page to view their subscription expiration date and to purchase extensions. Purchases may be made by check or money order. Credit card purchasing will be available shortly. (Note to installers: you may purchase Enlighten subscriptions from your distributor; please contact your distributor for appropriate pricing.)
How do I use the Array Builder?

If you are an installer, you have access to the Array Builder which will allow you to create your system owners' arrays within Enlighten.

Once you register a system and the activation has reached Step 3: Verification, you are ready to begin. You will need to have your install map handy to guide you on microinverter placement. You can launch the Array Builder from either the Activation page or the "Settings" page of the system within Enlighten.

Visit the learning center, where you can watch brief videos how to use the Array Builder.

Data and Networking

Do I need a broadband Internet connection to use Enlighten? Can't I just use dial-up?
A broadband connection is required for Enlighten support. Also, in situations where the installer would like troubleshooting assistance from Enphase Customer Support, a broadband connection is required in order to perform the troubleshooting.
Will the Enphase system work without implementing Enlighten? What data is available if I don't connect my Envoy to the Ethernet?
Usage of the Enlighten web monitoring is highly recommended for all Enphase Energy Microinverter System installations. However, if there is no internet access at the installation site, it is still possible to communicate directly with the Envoy using the Ethernet port and a personal computer with a web browser. Instructions for how to connect are available in the Envoy user manual (available off the Downloads page) and you can view an extract of the manual to see what level of data is available via the local interface.
Will Enphase change or otherwise impact my existing home computer network?
No. An Enphase Microinverter System will require no changes to the on-premise network, and will require no changes to the perimeter firewall, unless there are constraints already placed on traffic originating from the inside.
Do I need to have any special software installed on my home computer?
No. All Enphase user-interface elements are accessed via a common, Internet web-browser.
How much data will the Envoy (EMU) hold if it is disconnected from the internet?
The Envoy can store up to 400MB of data. For example, this means an Enphase system with 30 microinverters would store up to 400 days' worth of data.

Technical

Does the inverter have a neutral wire?
Yes. The inverters are connected to 240V line-to-line, split phase, and the neutral is used for the communication network.
Do the Enphase Microinverters automatically disconnect when the grid shuts down (e.g. for power company repairs)?
Yes. Enphase Microinverters are CSA-listed to the UL 1741 standard for utility-interactive applications. If the utility voltage source is out of voltage or frequency spec, or if the utility is disconnected, the inverter will not feed current or voltage to the grid side terminals. This functionality is implemented with any grid-tied inverter, so it will not "island" and potentially hurt line workers.
The Enphase Microinverter manual states that the device is positively grounded. Don't most PV modules have negative grounds? Is this a problem for Enphase?
Enphase made the decision to positively ground its microinverters to minimize corrosion. Because Enphase Microinverters are positively grounded, they are compatible with both positively and negatively grounded modules.

Support

If I have an operational problem, do I contact Enphase or my solar installer?
You are welcome to contact Enphase toll-free at (877) 797-4743, but you may want to contact your installer first if you have a maintenance contract with that installer.