FAQs

General Features

What is a Micro-inverter? What is a Micro-inverter system?
An inverter is a power converter that converts direct current (DC) into alternating current (AC). Traditionally, this has meant one, centrally-located inverter converting all of the DC current from the entire PV array into grid-compliant AC power. A Micro-inverter is a fully integrated 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, and to the service panel. A Micro-inverter system, then, is a federation of multiple micro-inverters all along a branch circuit, and/or within multiple branch circuits, which are all converting DC to AC, all injecting their current upstream, and reporting back to Enphase in real-time regarding their individual performance.
What is an EMU?
The Envoy Energy Management Unit is the communications gateway device which relays performance statistics from the Micro-inverters 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 6 rating.
Smart
  • 24/7 monitoring on a per-module basis.
  • Eliminates concern about where to place a large inverter.
  • Dramatically reduced installation design.
  • Modules can be mis-matched and added as your requirements grow.
  • Panels do not need to be collocated.
How do Enphase Micro-inverters 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 Micro-inverter is architected as a standalone inverter. This modular design means the Enphase Micro-inverter offers the flexibility to work with most off-the-shelf solar modules.
Can Enphase Micro-inverters work in off-grid environments?
Enphase Micro-inverters have only been tested to work in grid-tied installations.
Can Enphase Micro-inverters work with other DC power sources such as wind installations?
Enphase Micro-inverters have only been designed and tested to work in solar PV installations.
Do Enphase Micro-inverters 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 micro-inverter 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 micro-inverters are designed for 240VAC residential, as well as 208VAC three-phase service.
What solar modules is the Enphase Micro-inverter compatible with?
The Enphase Micro-inverters (Model M175 240V and Model M175 208V) work with any 72 cell module (24V nominal) up to 210-215Wstc.

Configuration

How many Enphase Micro-inverters can be on a single branch circuit?
Following are the maximum Micro-inverters per branch circuit:
  • 240V split-phase power - 16 Micro-inverters per branch circuit
  • 208V three-phase power - 24 Micro-inverters per branch circuit
There can be an unlimited number of branch circuits per installation.
Do all my modules need to match?
No. One of the advantages of a Micro-inverter 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.
How many branch circuits (total) can I have?
The EMU can currently manage a maximum of 180 Micro-inverters in the 240V split-phase model. A 240V split-phase branch can have a maximum of 16 Micro-inverters, equivalent to a maximum of 11 AC branches if those branches are fully populated.
Do I need an A/C disconnect on my roof for each Enphase branch-circuit?
This varies by Authority Having Jurisdiction (AHJ).

Installation

Who performs the installation for the Enphase system?
The Enphase system can be installed by any qualified solar installation company. The Micro-inverter 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 Micro-inverter System?
The A/C pigtail cable assembly terminates the first micro-inverter 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.

Regulatory and Compliance

Are Enphase devices UL-approved?
The Enphase Micro-inverters are CSA listed per the requirements of UL1741 and are therefore approved to operate in the United States and Canada.

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". A new temporary password will be generated and emailed to you.
How does the Micro-inverter communicate with the EMU?
The Micro-inverters utilize the existing power-line conductors.
How do I get notified when there is an error?
The Enlighten website allows for email alerting of critical issues.

Data Networking

Do I need a broadband Internet connection? Can't I just use dial-up?
No. A broadband connection is required.
Will Enphase change or otherwise impact my existing home computer network?
No. An Enphase Micro-inverter 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.

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.

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.