I NS TA L L A TI O N A N D O P E R A TI O N MA NU A L Enphase M250 Microinverter with integrated ground—no GEC required 141-00022, Rev 01
M250 Installation and Operation Contact Information Enphase Energy Inc. 1420 N. McDowell Blvd. Petaluma, CA 94954 http://www.enphase.com info@enphaseenergy.com support@enphaseenergy.com FCC Compliance This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation.
M250 Installation and Operation Table of Contents Important Safety Information ......................................................................................................................... 4 Read this First..................................................................................................................................................4 Safety Instructions .............................................................................................................................
M250 Installation and Operation Important Safety Information Read this First This manual contains important instructions for use during installation and maintenance of the Enphase M250™ Microinverter. To reduce the risk of electrical shock, and to ensure the safe installation and operation of the Enphase Microinverter, the following safety symbols appear throughout this document to indicate dangerous conditions and important safety instructions.
M250 Installation and Operation The Enphase Microinverter System ® The Enphase Microinverter System™ is the world’s most technologically advanced inverter system for use in utility-interactive applications. The model M250 Microinverter is more powerful and safer than previous models, and can be paired with higher-powered PV modules. In addition, the DC circuit within the M250 is isolated and insulated from ground. Because of this, the M250 does not require a GEC.
M250 Installation and Operation How the Microinverter Works The Enphase Microinverter maximizes energy production from your photovoltaic (PV) array. Each Enphase Microinverter is individually connected to one PV module in your array. This unique configuration means that an individual Maximum Peak Power Point Tracker (MPPT) controls each PV module.
M250 Installation and Operation Planning for Microinverter Installation Because the DC circuit is isolated and insulated from ground, the M250 does not require a GEC. The M250 is compatible with most 60-cell PV modules (to 300W or higher) and installs quickly and easily. It works with either three-phase 208 VAC or single-phase 240 VAC services. The M250 ships with integrated DC and AC cables and connectors.
M250 Installation and Operation Parts and Tools Required In addition to the microinverters, PV modules, and racking, you will need the following. Enphase Equipment Enphase Envoy Communications Gateway (optional, but recommended) BEST PRACTICE: Connect the Envoy before the solar installation is complete. When powered up and connected for the first time, the Envoy may retrieve an automatic upgrade from Enphase.
M250 Installation and Operation Enphase Microinverter Installation Installing the Enphase Microinverter System involves several key steps. Each step listed here is detailed in the following pages. Follow the instructions in this section to install Enphase M250 Microinverters.
M250 Installation and Operation Step 1: Connect the Envoy a. Connect the Envoy to power and Internet according to the Envoy Quick Install Guide. b. Wait for the “+Web” indication on the Envoy’s LCD screen. c. Leave the Envoy running while you install the microinverters so that any required Envoy software upgrade completes. BEST PRACTICE: When powered up and connected for the first time, the Envoy may retrieve an automatic upgrade from Enphase.
M250 Installation and Operation Step 2: Install the AC Branch Circuit Junction Box DANGER: Risk of Electrical Shock. Be aware that installation of this equipment includes risk of electric shock. Do not install the AC junction box without first removing AC power from the Enphase System. WARNING: Only use electrical system components approved for wet locations. WARNING: Do NOT exceed the maximum number of microinverters in an AC branch circuit as listed on page 30 of this manual.
M250 Installation and Operation Step 3: Plan, Cut, and Position the Engage Cable 2 The Engage Cable is a continuous length of 12 AWG (2.5 mm ), outdoor-rated cable with integrated connectors for microinverters. These connectors are preinstalled along the Engage Cable at intervals to accommodate PV module widths. The microinverters plug directly into the connectors, and the Engage Cable is terminated into the junction box that feeds electricity back to the system AC disconnect.
M250 Installation and Operation Step 4: Attach the Microinverters to the PV Racking a. Mark the approximate centers of each PV module on the PV racking. b. Evaluate the location of the microinverter with respect to the PV module DC junction box or any other obstructions. c. Ensure that the microinverter does not interfere with the PV module frame or stiffening braces. d. Ensure that the connector from the microinverter can easily reach the connector on the Engage Cable. e. Allow a minimum of 1.9 cm (0.
M250 Installation and Operation Step 5: Dress the Engage Cable NOTE: Adhere to the following requirements: Do not expose the connection to directed, pressurized liquid (water jets, etc.). Do not expose the connection to continuous immersion. Do not expose the AC connector to continuous tension (e.g., tension due to pulling or bending the cable near the connection) Use only the connectors and cables provided. Do not allow contamination or debris in the connectors.
M250 Installation and Operation Step 6: Connect the Microinverters a. Remove and discard the temporary shipping caps from the Engage Cable and connect the microinverter. There are two latching mechanisms within the connectors. Listen for two clicks as the connectors engage. Ensure that both latching mechanisms have engaged. b. Repeat for all microinverters in the AC branch circuit. c. Cover any unused connector with a sealing cap. Listen for two clicks as the connectors engage.
M250 Installation and Operation Step 7: Terminate the Unused End of the Engage Cable WARNING: Risk of Electrical Shock. The terminator cap must not be installed while power is connected. NOTE: Adhere to the following requirements: a. Use the terminator only once. If you open the terminator following installation, the latching mechanism is destroyed. Do not reuse the terminator. If the latching mechanism is defective, do not use the terminator.
M250 Installation and Operation Step 8: Connect the Engage Cable to AC Junction Box(es) a. Connect Engage Cable into the AC branch circuit junction box using an appropriate gland or strain relief fitting. The Engage Cable requires a strain relief connector with an opening of 1.3 cm (0.5 inches) in diameter. b. Connect the Engage Cable into additional AC junction boxes as needed to transition to conduit between smaller sub-arrays. Refer to the wiring diagrams on page 33 for more information.
M250 Installation and Operation Step 9: Complete the Installation Map The Enphase Installation Map is a diagrammatic representation of the physical location of each microinverter in your PV installation. You will create the virtual array in Enlighten from this map. Use the blank map on page 32 to record microinverter placement for the system, or provide your own layout if a larger or more intricate installation map is required.
M250 Installation and Operation Commissioning and Operation WARNING: Qualified personnel only may connect the Enphase Microinverter to the utility grid after receiving prior approval from the electrical utility company. WARNING: Ensure that all AC and DC wiring is correct. Ensure that none of the AC and DC wires are pinched or damaged. Ensure that all AC junction boxes are properly closed. Energize the System 1. Turn ON the AC disconnect or circuit breaker for each microinverter AC branch circuit. 2.
M250 Installation and Operation Build the Virtual Array When the system is energized and the Envoy detects at least one microinverter, create the virtual array in Enlighten from the installation map you created. You can scan and upload the paper copy of the Installation Map, or you can use the ArrayGun feature from the Enphase Installer Toolkit to easily build and configure a system. Refer to http://enphase.com/products/arraygun/ for more information. To scan and upload the map and build the array: 1.
M250 Installation and Operation Troubleshooting Adhere to all the safety measures described throughout this manual. Qualified personnel can use the following troubleshooting steps if the PV system does not operate correctly. WARNING: Do not attempt to repair the Enphase Microinverter; it contains no userserviceable parts. If it fails, contact Enphase customer service to obtain an RMA (return merchandise authorization) number and start the replacement process.
M250 Installation and Operation Troubleshoot an Inoperable Microinverter To troubleshoot an inoperable microinverter, follow the steps in the order shown. WARNING: Always de-energize the AC branch circuit before servicing. Never disconnect the DC connectors under load. Disconnect DC connections first, then disconnect the AC connections. WARNING: The AC and DC connectors on the cabling are rated as a disconnect only when used with an Enphase Microinverter.
M250 Installation and Operation 9. Disconnect and re-connect the DC PV module connectors. The Status LED of each microinverter will light solid green a few seconds after connection to DC power and then blink green six times to indicate normal start-up operation about two minutes after connecting to DC power. The LED subsequently resumes normal operation if the grid is present. See page 21 for normal LED operation. 10.
M250 Installation and Operation Disconnect a Microinverter If problems remain after following the troubleshooting steps listed previously, contact Enphase at support@enphaseenergy.com. If Enphase authorizes a replacement, follow the steps below. To ensure the microinverter is not disconnected from the PV modules under load, adhere to the following disconnection steps in the order shown: 1. De-energize the AC branch circuit breaker. 2.
M250 Installation and Operation Install a Replacement Microinverter If problems remain after troubleshooting, contact Enphase at support@enphaseenergy.com. If Enphase authorizes a replacement (RMA), replace the microinverter as follows: 1. When the replacement M250 is available, verify that the AC branch circuit breaker is deenergized. 2. Attach the replacement microinverter to the PV racking using hardware recommended by your PV racking vendor.
M250 Installation and Operation Engage Cable Planning and Ordering Information 2 The Engage Cable is a continuous length of 2.5 mm (12 AWG), outdoor-rated cable with integrated connectors for microinverters. These connectors are preinstalled along the Engage Cable at intervals to accommodate PV module widths. The microinverters plug directly into the cable connectors. The cabling is compatible with a variety of PV racking systems.
M250 Installation and Operation Voltage Type and Conductor Count Options The voltage types are either 240 VAC split phase or 208 VAC three phase. All cable connectors bear labels indicating their cable voltage designation. Typically used for residential applications, 240VAC includes four conductors. Three-phase 208 VAC cabling includes five conductors, and is used for most commercial installations.
M250 Installation and Operation You can sometimes avoid skipping Engage Cable connectors with the use of Engage Couplers. The Engage Coupler can be used to connect two Engage Cables or to connect Engage Cable to field cable. There are many possible scenarios for each type of connection, but they generally fall into four categories: o Engage Cable to Engage Cable: 1. Make use of leftover lengths of Engage Cable 2.
M250 Installation and Operation Technical Data Technical Considerations The M250 may be paired only with a 60-cell PV module. The PV module DC conductors must be labeled "PV Wire" or "PV Cable” to be compliant with NEC 690.35(D) for Ungrounded PV Power Systems. Be sure to verify the voltage and current specifications of your PV module match those of the microinverter. WARNING: You must match the DC operating voltage range of the PV module with the allowable input voltage range of the Enphase Microinverter.
M250 Installation and Operation Enphase M250 Microinverter Parameters Topic Unit Min Typical Max AC Parameters Rated continuous AC output power (-40C to +65C) W 240 Peak AC output power W 250 Output power factor >0.
M250 Installation and Operation Enphase M250 Microinverter Parameters Topic Unit Min Typical Max Features and Specifications Compatibility Pairs with most 60-cell PV modules (the PV module DC conductors must be labeled "PV Wire" or "PV Cable” to be compliant with NEC 690.35(D) for Ungrounded PV Power Systems) Dimensions not including mounting bracket (approximate) 171 mm x 173 mm x 30 mm Weight 2 Kg Enclosure environmental rating NEMA 6 Torque specifications for fasteners (Do not over torque.
M250 Installation and Operation Enphase Installation Map 32 2013 Enphase Energy Inc.
M250 Installation and Operation M250 Dimensions 33 2013 Enphase Energy Inc.
M250 Installation and Operation Sample Wiring Diagram: M250, 240 VAC 34 2013 Enphase Energy Inc.
M250 Installation and Operation Sample Wiring Diagram: M250, 208 VAC 35 2013 Enphase Energy Inc.
Enphase Energy Inc. 1420 N. McDowell Boulevard Petaluma, CA 94954 www.enphase.com info@enphaseenergy.com support@enphaseenergy.
