Power One AURORA MICRO-0.25-I-OUTD-US-208/240, AURORA MICRO-0.3-I-OUTD-US-208/240 User Manual

THE MANUAL: MICRO

Model Number: MICRO-0.25-I-OUTD-US-208/240
MICRO-0.3-I-OUTD-US-208/240

AURORA MICRO ®

Grid Tied Inverters

MICRO-0.25/0.3-I-OUTD-US-208/240

Technical Manual

Page 2 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Copyright © 2013 Power-One Renewable Energy Solutions LLC. All rights reserved. No part of this

document may be reproduced in any form or by any means without the prior written permission of

Power-One Renewable Energy Solutions LLC. Power-One Renewable Energy Solutions LLC makes

no representations, express or implied, with respect to this document or any of the equipment

and/or software it may describe; including (without limitation) any implied warranties of utility, or

merchantability for any particular purpose. All such warranties are expressly disclaimed. Power-

One Renewable Energy Solutions, LLC, its subsidiaries, affiliates, distributors and dealers shall not

be liable for any indirect, special, incidental, or consequential damages under any circumstances.

Power-One Renewable Energy Solutions LLC reserves the right to make changes to this document

without notice and shall not be responsible for any damages, including indirect, special, incidental

or consequential damages, caused by reliance on the content presented, including, but not limited

to, any omissions, typographical errors, arithmetical errors or listing errors. All trademarks, logos,

trade names, service marks and copyrighted materials used in this document are the property of

their respective owners. Failure to designate a mark as registered does not mean that such mark is

not a registered trademark. The Power-One name and logo are registered trademarks of Power-

One, Inc. in the U.S.A. and other countries. All rights reserved. No licenses are conveyed herein,

implicitly or otherwise, under any intellectual property rights.

Power-One

Renewable Energy Solutions LLC

740 Calle Plano

Camarillo, California, 93012

United States of America

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Revision
Number

Author

Date

Approved by

Description of
Modification

AA

Tech docs

12/6/12

BCG.00612,
BCM.00138

New release

AB

Tech docs

2/4/13

BCG.00612,

New data sheet,

Table of Revisions

BCM.00138

new label,
modify overcurrent
table 3-1

Page 4 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Contents

PART 1 INTRODUCTION AND SAFETY ....................................................................................................................... 5

1.1 INTRODUCTION ................................................................................................................................................................................ 6

1.2 SAFETY ............................................................................................................................................................................................ 10

1.3 SYSTEM INTEGRATION ................................................................................................................................................................. 20

PART 2 UNPACK AND SELECT INSTALLATION LOCATION .............................................................................. 21

2.1 GENERAL CONDITIONS ................................................................................................................................................................. 22

2.2 SELECT INSTALLATION LOCATION ............................................................................................................................................. 24

2.3 CHOICE OF AC CABLE ................................................................................................................................................................... 28

PART 3 MOUNTING AND WIRING ............................................................................................................................. 30

3.1 ASSEMBLY DIAGRAM .................................................................................................................................................................... 31

3.2 ASSEMBLY INSTRUCTIONS ........................................................................................................................................................... 32

3.3 WIRING DETAILS ........................................................................................................................................................................... 40

3.4 CONNECTION TO THE AC DISTRIBUTION GRID (AC SIDE) ...................................................................................................... 42

3.5 WIRING OF AC CABLE .................................................................................................................................................................. 43

PART 4 OPERATIONS GUIDE ...................................................................................................................................... 44

4.1 GENERAL CONDITIONS ................................................................................................................................................................. 45

4.2 DISPLAY AND KEYPAD .................................................................................................................................................................. 45

4.3 COMMISSIONING ............................................................................................................................................................................ 48

PART 5 TROUBLESHOOTING ...................................................................................................................................... 50

5.1 ALARM MESSAGES GENERATED BY THE MICRO INVERTER .................................................................................................. 51

5.2 VERIFICATION OF GROUND LEAKAGE ........................................................................................................................................ 55

5.3 MEASURING THE INSULATION RESISTANCE OF PHOTOVOLTAIC MODULE .......................................................................... 56

5.4 THE POWER-0NE SERVICE CALL ................................................................................................................................................ 58

PART 6 MAINTENANCE GUIDE ................................................................................................................................... 59

6.1 GENERAL CONDITIONS ................................................................................................................................................................. 60

6.2 STORAGE AND DISMANTLING ...................................................................................................................................................... 62

PART 7 APPENDIX .......................................................................................................................................................... 63

7.1 TECHNICAL DATA .......................................................................................................................................................................... 64

7.2 TEMPLATE FOR MAP OF MICRO INVERTER INSTALLATION ................................................................................................. 75

7.3 INDEX OF TABLES AND FIGURES ................................................................................................................................................. 76

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Technical Manual

PART 1 INTRODUCTION AND SAFETY

Page 6 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 1 Introduction and Safety

1.1 INTRODUCTION

This manual contains important instructions for models indicated on the front cover that shall be
followed during installation and maintenance of the inverter.

THE INSTALLER MUST READ THIS DOCUMENT IN ITS ENTIRETY BEFORE INSTALLING OR
COMMISSIONING THIS EQUIPMENT.

1.1.1 PURPOSE

The purpose of this document is to support the qualified technician, who has received training
and/or has demonstrated skills and knowledge in construction to install and maintain this Power­One AURORA MICRO ® grid tied inverter. This manual does not cover any details concerning
equipment connected to the inverter such as the solar modules. Information concerning the
connected equipment is available from the respective manufacturer.

This manual is a guide that will enable installers to work safely, install the MICRO system and
maintain it in good working order.

1.1.2 INSTALLATION

The installation is to be done by a qualified installer, normally a licensed electrician or contractor,
according to the applicable local code regulations (National Electric Code (NEC), Canadian Electric
Code (CEC), and other).

For safety reasons only a qualified electrician, who has received training and/or has demonstrated
skills and knowledge in construction and in operation of this unit, can install this inverter.

1.1.3 VALIDITY AND AVAILABLE MODELS

There are two models of the MICRO, delineated by the maximum output power (0.25 kW or 0.3
kW). Each version is also available for either a 240Vac split phase or 208Vac single phase AC grid
connection.

This document applies only to the inverter models listed in Table 1-1. All model dimensions are

15.0” x 9.7” x 1.37” and weigh 3-1/2 lb (1.65kg).

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Output power

Model number

250 Watts

MICRO-0.25-I-OUTD-US-208/240

300 Watts

MICRO-0.3-I-OUTD-US-208/240

Part 1 Introduction and Safety

Table 1-1: Inverter models available

1.1.4 NAMEPLATE

The nameplate shown below is affixed to the inverter and provides the following information:

Table 1-2: Product nameplate

Certification

Model name

DC Rating

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Part 1 Introduction and Safety

AC Rating

Environmental

rating

Serial number

MAC address

1.1.5 COMMISSIONING

Power-One can provide commissioning (initial setup and power up). Please contact Power-One
Customer Service at 1-877-261-1374.

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Part 1 Introduction and Safety

1.1.6 MAINTENANCE AND SERVICE

The MICRO inverter has no user-serviceable parts. Maintenance and service procedures must
comply with the manufacturer's documentation. For more detailed information see Maintenance,
Part 6, in this document.

1.1.7 FIGURES AND IMAGES IN THIS MANUAL

The photos in this manual may differ slightly from the final model shipped and the color of the

components may not match those illustrated; however, the information is still applicable.

1.1.8 STORAGE OF THIS INFORMATION

Keep this document in a safe place near the AURORA MICRO inverter for easy access during
installation and maintenance. It must be accessible for approved service and maintenance
personnel at any time.

1.1.9 ADDITIONAL INFORMATION

More information on Power-One’s AURORA MICRO inverter can be found at www.power-one.com.

1.1.10 CONDITIONS OF WARRANTY

Warranty Conditions can be found on the Power-One Renewable Energy website located in the
download section of the AURORA MICRO inverter product page.

Page 10 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Symbol

Usage

Indicates a hazardous situation that can result in deadly electric shock hazards,
other serious physical injury, and/or fire hazards.

Indicates directions which must be fully understood and followed in entirety in
order to avoid potential safety hazards including equipment damage or personal
injury.

This points out that the examined area must not be entered or that the described
operation must not be carried out. The reader should stop, use caution and fully
understand the operations explained before proceeding.

DANGEROUS VOLTAGE

The product works with high voltages. All work on the AURORA Inverter must

regulations associated with high voltages. During inverter operation, parts will be
energized at voltage levels.

Some surfaces may become hot. Do not touch the product while it is in operation.

UL 1741 Standard for Safety for Inverters, Converters, Controllers and
Interconnection System Equipment for use with Distributed Energy Resources.
CSA CSA-C22.2 No. 107.1-01 - General Use Power Supplies.

Part 1 Introduction and Safety

IMPORTANT SAFETY INSTRUCTIONS!

SAVE THESE INSTRUCTIONS – KEEP IN A SAFE PLACE!

1.2 SAFETY

1.2.1 WARNINGS IN THIS DOCUMENT

This is a list of special safety symbols used in this manual that highlights potential safety risks
and/or useful information. The symbol usage is described below:

DANGER:

WARNING:

CAUTION:

WARNING

WARNING

follow the described documentation and must comply with all prevailing codes and

HOT TEMPERATURE

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System earth conductor (main grounding protective earth,
PE)

Alternating Current (AC) Value

Direct Current (DC) Value

ø

Phase

Grounding (earth)

Part 1 Introduction and Safety

1.2.1.1 Equipment Safety Warnings

In addition to the safety and hazard symbols, the following symbols are also used in this installation
guide:

The equipment has various labels. Those with a yellow background refer to safety concerns. Be sure
to read all labels before beginning installation of the equipment. If any questions arise as to the
meaning or intent of these notices, please contact Power-One Technical Support at 877-261-1374.

1.2.1.2 General Installation Warnings

The AURORA MICRO inverter is designed and tested according to international safety requirements
(Ul 1741/IEEE 1547); however, certain safety precautions must be observed when installing and
operating this inverter. The installer must read and follow all instructions, cautions and warnings
in this installation manual.

The UL1741 requires the following voltage and frequency limits for utility interaction listed in the
table below:

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Condition

Simulated utility source

Maximum time (sec) at 60

Hz before cessation of

current to the simulated

utility

Voltage (V)

Frequency (Hz)

A

V< 50% V

nor

(Not Adjustable)

Rated

0.16 sec

(Not Adjustable)

B

50%V

nor

≤ V< 88% V

nor

(Adjustable Set Points 55% to

88%)

Rated

2 sec (Default)

(Adj. Set Points 0.16 sec

to 5 sec)

C

110%V

nor

≤ V< 120% V

nor

(Adjustable Set Points 110% to

118%)

Rated

1 sec (Default)

(Adj. Set Points 0.16 sec

to 5 sec)

D

V≥120% V

nor

(Not Adjustable)

Rated

0.16 sec

(Not Adjustable)

E

Rated

f > 60.5

(Not Adjustable)

0.16 sec

(Not Adjustable)

F

Rated

f < 59.3 (Default)

(Adj. Set Points 59.8

Hz to 57.2 Hz)

0.16 sec (Default)

(Adj. Set Points 0.16 sec

to 300 sec)

G

Rated

f < 57.0

(Not Adjustable)

0.16 sec

(Not Adjustable)

All operations regarding transport, installation and start-up, including
maintenance, must be carried out by qualified, trained personnel and in
compliance with all prevailing local codes and regulations.

Basic safety rules require using qualified and trained personnel possessing the
skills necessary for assembly, mounting, start up and operation of the product.

Part 1 Introduction and Safety

Table 1-3: Voltage and frequency trip limits

WARNING:

Page 13 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Systems with inverters typically require additional control (e.g., switches,

Power-One DOES NOT provide AC output overcurrent protection. To

The AC output (neutral) is not bonded to ground.

Electric Code, ANSI/NFPA 70, and is the responsibility of the installer.

Part 1 Introduction and Safety

1.2.1.3 Assembly Warnings

Prior to installation, inspect the unit to ensure absence of any transport or handling damage, which
could affect insulation integrity or safety clearances; failure to do so could result in safety hazards.

Assemble the inverter per the instructions in this manual. Use care when choosing installation
location and adhere to specified cooling requirements.

Unauthorized removal of necessary protections, improper use, incorrect installation and operation
may lead to serious safety and shock hazards and/or equipment damage.

1.2.1.4 Electrical Connection Warnings

This grid-tied inverter system operates only when properly connected to the AC -distribution
network. Before connecting the AURORA MICRO to the power distribution grid, contact the local
power distribution grid company to get appropriate approvals. This connection must be made only
by qualified technical personnel

disconnects) or protective devices (e.g., fusing circuit breakers) depending
upon the local safety regulations.

It is the responsibility of the installer to provide external disconnect

CAUTION:

WARNING:

CAUTION:

switches and Overcurrent Protection Devices (OCPD) as required by
National Electric Codes and other prevailing regulations.

reduce the risk of fire, connect only to a circuit provided with 20A
maximum branch circuit overcurrent protection in accordance with the
National Electric Code (ANSI/NFPA 70).

Make all electrical connections (e.g. conductor termination, fuses, PE
connection, etc.) in accordance with the electrical standards prescribed by
the applicable National Electric Code, ANSI/NFPA 70 wiring methods
and/or by other local regulations and codes.

The input and output circuits are isolated from the enclosure and the
system grounding shall be installed per the requirements of the National

Page 14 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

accepts NO liability for damage of any kind that may arise from incorrect
or careless operation. The equipment must not be used in ways that do not fall
within the intended field of use.

Part 1 Introduction and Safety

1.2.2 APPROPRIATE USAGE

Power-One

CAUTION:

1.2.2.1 Intended or Allowed Use

This equipment is
photovoltaic module (PV) into an alternating current
distribution grid.

This MICRO Inverter is designed for outdoor use, but can be used indoors if installed according to
the National Electric Code and abiding by specified environmental and mounting parameters as
stated in this manual (see Environmental Conditions section 1.2.2.3 and General Installation
Conditions section 2.2.2).

a

MICRO inverter designed to transform direct current (DC) coming from a

(AC)

suitable for being fed into the power

1.2.2.2 Conditions of Use

The operating current output during the normal operation MUST NOT exceed the limits
documented in

the technical specifications.

Only one photovoltaic module can be connected in the input of the inverter (DO NOT connect
batteries or other sources of power supply).

The inverter can be connected to the electricity grid in qualified countries ONLY.

The inverter can be used only if all the technical characteristics are observed and applied.

1.2.2.3 Environmental Conditions

Adverse environmental condition, such as: sun, rain, snow, wind, too hot or too cold, altitudes,
humidity, etc., can lead to a reduction in performance.

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Part 1 Introduction and Safety

1.2.2.4 Improper or Prohibited Use

The following actions are dangerous and strictly forbidden under the terms of the warranty:

• Installing the equipment in environments with flammability conditions or in

adverse/constrained environmental conditions (temperature and humidity).

• Using the equipment with safety devices not working or disabled.

• Using the equipment or parts of the equipment by connecting it to other machines or

equipment, unless otherwise expressly allowed in this manual.

• Modifying the operating parameters that are restricted to the installer.

• Cleaning with corrosive products that may corrode parts of the equipment or generate

electrostatic charges.

• Using or installing the equipment or its parts without having read and correctly interpreted

the contents of the operating and maintenance manual.

Page 16 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Warning – These servicing instructions are for use by qualified personnel only.

To reduce the risk of electric shock, do not perform any servicing other than that
specified in the operating instructions.

Part 1 Introduction and Safety

1.2.3 SAFETY INSTRUCTIONS

Be sure all flammable materials including construction items are away from the unit. Do not install
the inverter in or near potentially explosive areas.

Normally grounded conductors may be ungrounded and energized when a ground-fault is indicated
resulting in risk of electric shock. Test voltage with a voltmeter before touching.

Do not connect an AURORA MICRO inverter to the electrical distribution grid until after the receipt
of a letter of authorization from the authority having jurisdiction.

Install the AURORA Inverter in accordance with the electrical standards prescribed by the
applicable National Electric Code (NEC), Canadian Electric Code (CEC), and/or by other local codes
and regulations.

Use personal protective equipment; including gloves and eye protection when working on this unit.

1.2.3.1 General Information

The equipment has been manufactured in accordance with the strictest accident-prevention
regulations and supplied with safety devices suitable for the protection of components and
operators. Inform the manufacturer about non-standard installation conditions.

Maintenance operations must be carried out according to the Maintenance section in Part 6 of this
manual.

The connection of an inverter energy system to an electrical installation connected to the electricity
distribution network shall be approved by the appropriate electric utility.

It is essential to provide operators with correct information. They must therefore read and comply
with the technical information given in the manual and in the attached documentation.

Page 17 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Warning - Certain parts may be extremely hot immediately following shut down

due to normal elevated surface temperatures (e.g. transformers, accumulators,
coils etc.).

Part 1 Introduction and Safety

The instructions given in the manual do not replace the safety devices and technical data for
installation and operation mounted on the product. They do not replace the safety regulations
enforced in the country of installation and common sense rules.

The manufacturer is willing to train staff, at its premises or on site, in accordance with conditions to
be set out in the contract.

Do not use the equipment if any operating anomalies are found. Avoid temporary repairs.

All repairs should be carried out using only qualified spare parts, which must be installed in
accordance with their intended use and by a licensed contractor or authorized Power-One Service
representative.

Liabilities arising from commercial components are delegated to their respective manufacturers.

1.2.3.2 Thermal Hazard

Prior to touching any part of the inverter use care to ensure surfaces and equipment are at touch­safe temperatures and voltage potentials before proceeding.

Anytime the inverter has been disconnected from the power network, use extreme caution as some
components can retain charge sufficient to create a shock hazard. To minimize occurrence of such
conditions, comply with all corresponding safety symbols and markings present on the unit and in
this manual.

Page 18 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 1 Introduction and Safety

1.2.4 LOCATION OF SAFETY LABELS

Please note the location of the safety notices on the AURORA MICRO inverter. These and the
product nameplates are for notification and protection.

Figure 1-1: Safety label location

The labels and plates attached to the equipment must NOT be removed, damaged, hidden, etc. They
must be cleaned regularly and kept visible at all times. This means they must NOT be hidden with
objects and extraneous parts (rags, boxes, equipment, etc.).

The technical data shown in this manual does not replace those shown on the plates attached to the
equipment.

Page 19 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 1 Introduction and Safety

1.2.1 OTHER LABELS

In addition to the safety label and product nameplate,there is one identification label on the
inverter. A duplicate label is attached in a plastic bag as shown below and will be used later to fill in
the “system map” for the monitoring software. It is recommended to make a copy of the “system
map” for the installer.

Figure 1-2: Identification label for adhering to system map

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Part 1 Introduction and Safety

1.3 SYSTEM INTEGRATION

This system is composed of a group of MICRO inverters that convert direct electric current from a
photovoltaic module into alternating electric current and feeds it into the electric grid.

Photovoltaic modules transform energy from the sun into direct current (DC) electrical energy. In
order to use DC energy, it is necessary to transform the type of current into alternating current or
“AC”. This conversion, known as DC to AC inversion, is made efficiently without using rotating parts
and only through static electronic components.

In order to allow inverter operation in safe thermal and electrical conditions, in the event of
adverse environmental conditions or unsuitable input voltage values, the unit automatically
reduces the value of the power fed into the grid. This way the solar energy system compensates for
the energy drawn from the utilities connected to the grid to which it is linked. The solar energy
system therefore powers all connected electrical devices, from lighting to household appliances, etc.

When the photovoltaic system is not supplying sufficient power, the power needed to ensure
normal operation of the connected electrical devices is drawn from the grid. If, on the other hand,
excess power is produced, this is fed directly into the grid, becoming available to other consumers.

1.3.1 CHARACTERISTICS OF MICRO INVERTERS

Unlike systems subdivided into strings controlled by one or several inverters, systems of this sort
are built for the incorporation of a MICRO inverter for each photovoltaic module

.

Each MICRO inverter works independently of the others, thus its own photovoltaic module supplies
the maximum power available to the grid. This setup enables direct control over the production of a
single photovoltaic module, consequently optimizing production as much

as possible.

1.3.2 NOTES ON SIZING OF THE SYSTEM

Decisions about how to structure a photovoltaic system depend on a number of factors and
considerations depending on the type of modules, the availability of space, possible future
expansion of the system, and the energy production goals over the long term, etc.

A configuration program that can help to correctly size the photovoltaic system is available on the
Power-One website at www.power-one.com

.

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Technical Manual

PART 2 UNPACK AND SELECT

INSTALLATION LOCATION

Page 22 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 2 Unpack and Select Installation Location

2.1 GENERAL CONDITIONS

Some specifications are not applicable to small equipment or components.

2.1.1 TRANSPORT AND HANDLING

Transportation of the equipment, especially by road, must be carried out by suitable ways and
means for protecting the components (in particular, the electronic components) from violent

,

etc

shocks, humidity, vibration

Power-One packages and protects individual components using suitable means to make its
transport and subsequent handling easier.

Discard packaging elements immediately as to not cause unforeseen injury. Packaging elements
(cardboard, cellophane, staples, adhesive, tape, straps, etc.) may cause cuts and/or injuries if not
handled with care. They should be removed by suitable means and disposed of in accordance with
any regulations enforced by the country of installation.

.

2.1.2 INCOMING INSPECTION

It is the customer’s responsibility to examine the condition of the unit shipped. Upon receipt of
Power-One’s AURORA Inverter, please perform the following check:

• Inspect the shipping container for any external damage.

• Inventory the contents against list below; verify receipt of all items. Use care not to discard

any equipment, parts, or manuals.

• Call the delivering carrier if damage or shortage is detected.

If inspection reveals damage to the inverter, contact the supplier, or authorized distributor for a
repair/return determination and instructions regarding the process.

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Code

Description

AC-TRUNK SPOOL-41 inches-50 plugs

AC cable (4 conductors):
10 AWG
Plug (connector) pitch 41”

AC-TRUNK SPOOL-67 inches-32 plugs

AC cable (4 conductors):
10 AWG
Plug (connector) pitch 67

”

AC-TRUNK SPOOL-81 inches-27 plugs

AC cable (4 conductors

):
10 AWG
Plug (connector) pitch 81

”

AC TRUNK PLUG CAP

Insulated AC cap for AC Bus connectors (female

)

AC TRUNK END CAP

End cap for 10 AWG AC cable

AC TRUNK UNLOCK
TOOL

Tool for releasing connectors

Part 2 Unpack and Select Installation Location

Table 2-1: List of components supplied

Page 24 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 2 Unpack and Select Installation Location

2.2 SELECT INSTALLATION LOCATION

2.2.1 OVERALL DIMENSIONS

The following figure shows the recommended minimum clearances around the inverter. The
overall dimensions are expressed in millimeters (mm) and inches (in).

Figure 2-1: Overall dimensions of MICRO inverter

Page 25 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

The installation is done by qualified installers and/or licensed electrician according
to the applicable local code regulations (National Electric Code (NEC), Canadian
Electric Code (CEC) and other local codes).

The connection of an inverter energy system to the electricity distribution network
shall be approved by the appropriate electrical distributor or authority having
jurisdiction.

The installation must be carried out with the equipment disconnected from the grid
(power disconnect switch open) and with the photovoltaic modules shaded or
isolated.

Part 2 Unpack and Select Installation Location

2.2.2 GENERAL INSTALLATION CONDITIONS

Installation of the equipment is carried out based on the system design and the place in which the
equipment is installed.

2.2.3 ENVIRONMENTAL CHECKS

• See Part 7: Appendix: Technical Data to check the environmental parameters to be

observed (degree of protection, temperature, humidity, altitude, etc.)

• To avoid unwanted power derating due to an increase in the internal temperature of the

inverter, do not expose it to direct sunlight.

• To avoid overheating, always make sure the flow of air around the inverter is not

blocked.

• Do not install in places where gasses or flammable substances may be present.

• Avoid electromagnetic interference that can compromise the correct operation of

electronic equipment.

2.2.4 HIGH ALTITUDE INSTALLATION (ABOVE 2000 METERS/6562 FEET)

Certain conditions should be considered when choosing an installation
location at high altitudes:

• Derating - Less efficient cooling; therefore, a greater likelihood of the device going into

derating because of high internal temperatures.

• Electric Arc - Reduction

high-operating voltages (DC input), can create electric arcs (electrical discharges) that
may reach the point of damaging the inverter.

in the dielectric resistance of the air that, in the presence of

All installations at altitudes of over 2000 meters/6562 feet must be assessed
case by case considering the aforesaid

criticalities.

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Part 2 Unpack and Select Installation Location

2.2.5 INSTALLATION POSITION

When choosing the place of installation, comply with the following conditions:

Install only on structures specifically conceived for photovoltaic modules (supplied by installation
technicians).

Install MICRO inverter underneath the photovoltaic modules so that they work in the shade. If this
condition cannot be met, the inverter could undergo derating.

Figure 2-2: Installation position of MICRO underneath PV module

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Part 2 Unpack and Select Installation Location

Any maintenance or replacement of the device could require the technician to dismount the
photovoltaic module mounted on the top of the MICRO inverter.

This condition must be accounted for during the installation ensuring that the safety distances are
correct for normal control and maintenance operations.

The distance between MICRO inverters installed on the same system array depends on the type of
photovoltaic modules and its orientation (horizontal or vertical).

Choose the best solution to employ during the project planning stage, bearing in mind that the
selected configuration will include the correct type of AC cable.

Figure 2-3: Installation orientation of MICRO considering distances

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Power-One Cable Item

Power-One Cable Item

AC-Trunk Spool – 67 inches

32 plugs *

AC-Trunk Spool – 81 inches

27 plugs *

Ideal for 60-cell or 96-cell

PV modules

Ideal for 72-cell PV modules

Part 2 Unpack and Select Installation Location

2.3 CHOICE OF AC CABLE

The AC cable is shipped on a reel with the connectors pre-mounted. The available spacing between
connectors is: 41”, 67”, and 81

The installer is responsible for choosing the AC cable model with the correct spacing on the basis of
the orientation (shown below) and type of photovoltaic modules.

Observe the certification documents concerning the maximum number of
MICRO inverters permitted for installation at each cable section!

”.

Figure 2-4: Horizontal orientation of the photovoltaic modules

Page 29 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Power-One Cable Item

AC-Trunk Spool – 41 inches

50 plugs *

Ideal for 60-cell, 72-cell, 96-cell

PV modules

Part 2 Unpack and Select Installation Location

Figure 2-5: Vertical orientation of the photovoltaic modules

* Note: The AC-TRUNK SPOOL may contain a number of connectors indicated by the number

of plugs in the part number. The installer may cut the cable to the length needed for the
specific installation.

Page 30 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Technical Manual

PART 3 MOUNTING AND WIRING

Page 31 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 3 Mounting and Wiring

3.1 ASSEMBLY DIAGRAM

Figure 3-1: Graphical representation of assembly instructions

Page 32 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

The cable must be compatible with the expected installation conditions,

installation! (See technical data found in the Appendix, Part 7, of this manual.)

3. The inverter and photovoltaic modules must be connected

to an equipment grounding conductor in accordance with

The inverter can be earth grounded using the connect clamp
secured to the chassis and an adequately-sized conductor.

Part 3 Mounting and Wiring

3.2 ASSEMBLY INSTRUCTIONS

1. Run the AC cable along the frame structure provided for installing the photovoltaic modules.

particularly concerning the number of modules and their orientation (portrait or
landscape).

Legislation in force in the country of installation and the installed power will
determine the maximum number of MICRO inverters permitted for installation at
each AC cable section.

Do NOT exceed the maximum number of MICRO inverters permitted for

2. Secure the MICRO inverter to the photovoltaic module frame with the logo side facing

downwards.

Mark the approximate center of each photovoltaic module on the frame in order to facilitate
positioning.

the pertinent legislation in force in the country of
installation.

There are two possible configurations for grounding the inverters shown below:

Page 33 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 3 Mounting and Wiring

Equipment grounding conductor coupling all the MICRO inverters:

The conductor must have a minimum cross section of 6 AWG (8AWG in conduits).

Figure 3-2: Equipment grounding conductor coupling all the inverters

Page 34 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Incorrect grounding can cause physical injury, death or equipment malfunction

regulations.

Part 3 Mounting and Wiring

Individual earth conductors for each MICRO inverter:

• The conductor linking the assembly to the grounding distribution structure must be at least

6 AWG.

• The conductor bonding the MICRO inverter to the structure must have a minimum cross

section of 8 AWG (maximum length 1m).

• Ensure that the quality of the bond made between the conductor and the structure is secure.

Only a racking system that is certified for use as a grounding structure is permitted to use
this method.

Figure 3-3: Configurations for grounding the MICRO inverters

and increase electromagnetic interference.
Make sure that grounding conductors are adequately sized as required by safety

Page 35 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 3 Mounting and Wiring

4. Fasten the AC-TRUNK cable to the frame with cable ties. Each connector is provided with two
guides for ideal fastening. Cable ties are not supplied with the inverter or AC-TRUNK cable. Use
cable ties that are rated for use in the installation location.

5. Remove the temporary cap from AC-TRUNK cable connectors and then connect the MICRO
inverters. The connectors are coupled correctly when two clicks are heard.

Be mindful to keep the connectors in a position accessible to the AC-TRUNK cable coming
from the MICRO inverter.

Protect any unused AC-TRUNK cable
connectors by fitting the AC-TRUNK PLUG CAP
on them to keep them watertight.

The temporary caps are only fitted for shipping
and provide no seal whatsoever!

Page 36 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

6. Fit the appropriate AC-TRUNK END CAP

cable.

Part 3 Mounting and Wiring

on the unused ends of the AC-TRUNK

7.

Connect the AC-TRUNK cable/s coming
from the MICRO inverters to the junction
box or to the AC distribution panel

.

8. Draw a map of the system,
appropriate

position on the diagram (found in the Appendix of this manual).

affixing the extra label that comes attached to each inverter, on the

Page 37 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

The recommended installation entails keeping the MICRO inverters

a length of less than 3m.

Part 3 Mounting and Wiring

9. Plug the DC cables into the corresponding

inputs on the MICRO inverters and install
the photovoltaic modules.

underneath the photovoltaic modules, having them operate in the shade.
Direct sunlight could cause elevated temperatures and consequently derating.

Each module must be connected to the MICRO-Inverter with a DC cable having

10. The inverter will not begin to feed energy into the

distribution grid until the association procedure of the
CDD (Concentrator Data Device) has been completed.

See the AURORA CDD Instruction Manual for the
procedures.

Page 38 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

• Insert the AC-TRUNK UNLOCK TOOL in the

two holes on the connector or cap.

Remove the connector or cap.

Part 3 Mounting and Wiring

3.2.1 INSTALLING THE AC-TRUNK END CAP

The unused ends of the AC-TRUNK cable must be terminated with the proper end.

The following is necessary for properly installing the cap:

1 Fit the ring nut and gasket around the cross section of the cable to terminate.
2 Strip 50 mm/1.97 inches of the external insulation and separate each conductor.
3 Insert the conductors into the recesses inside the cap to block them.
4 Insert the gasket into the cap with slight pressure.
5 Screw the ring nut to apply the correct pressure on the gasket (max.2.45Nm/1.81 ft-lbs).
6 Secure the section of the terminated cable to the frame structure with cable ties.

3.2.2 USE OF THE AC-TRUNK UNLOCK TOOL

The AC-TRUNK UNLOCK TOOL must be used for the disconnection of the AC connector from the
MICRO inverter or for the removal of the AC-TRUNK PLUG CAP from the connectors on the AC­TRUNK cable.

The tool is used to release the two retaining clips on the connectors installed on the AC-TRUNK
cables. The disconnection or cap removal can be performed in three simple steps:

• Press to release the retaining clips.

•

Page 39 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 3 Mounting and Wiring

The figures below illustrate the use of the AC-trunk unlock tool.

Figure 3-4: Disconnection of the MICRO inverter AC cable

Figure 3-5: Removing the AC trunk plug cap

Page 40 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Protection breaker

rating

MICRO-

0.25

4 7 12

15

MICRO-

0.3

3 6 9

12

MICRO-

0.25

4 6 10

13

MICRO-

0.3

3 5 8

11

It is the installer’s responsibility to adequately size the overcurrent protection,

each AC line.

Part 3 Mounting and Wiring

3.3 WIRING DETAILS

3.3.1 LOAD PROTECTION SWITCH (AC DISCONNECT SWITCH)

To protect each AC connection line of the MICRO inverter, it is required to install a device for
protection against overcurrent with the following characteristics:

Table 3-1: Overcurrent device recommended characteristics

6A 10A 16A 20A

Max number of

Inverters

@240VAC

Max number of

inverters

@208VAC

The dimensions of the thermal-magnetic circuit breaker should be determined by the number of
MICRO inverters connected to a single AC line. A 20A thermal-magnetic circuit breaker represents
the maximum value permitted for installation in a single AC line, sized based on the AC cable cross
section (10 AWG).

based on the number and types of MICRO inverters in the system (see Table

3-1). The maximum thermal-magnetic circuit breaker current rating is 20A for

Page 41 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

CAUTION: To reduce the risk of fire, connect only to a circuit provided with

National Electric Code (ANSI/NFPA 70)

Part 3 Mounting and Wiring

3.3.2 DIFFERENTIAL PROTECTION DOWNSTREAM OF THE INVERTER

Aurora Power-One inverters with a high frequency transformer are equipped with an isolation
transformer for each of the DC/DC converters which operate at high frequency (switch-over
frequency of the converter). This transformer allows for high frequency galvanic isolation between
the DC and AC side of the system. In addition to this the inverters include protection mechanisms so
that they cannot input ground fault currents.

Power-One recommends the use of a switch with type A or AC differential

magnetothermal protection with IΔn=30mA sensitivity.

3.3.3 CHOOSING THE INTERFACE PROTECTION SYSTEM

AND DEVICE DOWNSTREAM OF THE INVERTER

The inverter does not include any electromechanical devices (relays, contactors, etc.) for automatic
disconnection from the power grid. The system must therefore be provided with external
protection for the physical disconnection of the MICRO inverters from the grid, in compliance with
the applicable regulations and with the requirements of the installation country’s power
distributor.

Such protection is typically composed of an interface protection system that analyzes and controls
the grid parameters and, if necessary, sends commands to the interface device, in charge of
physically disconnecting the PV installation MICRO inverters line.

20A maximum branch circuit overcurrent protection in accordance with the

Page 42 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

To prevent electrical hazards, all the connection operations must be carried

When connecting to the grid, all the Power-One AC

The AC cable used is quadrupole

All the external connections to the insulated junction box (caps, adapters, etc.)

The installation technician is responsible for selecting a cable of the appropriate

Part 3 Mounting and Wiring

3.4 CONNECTION TO THE AC DISTRIBUTION GRID (AC SIDE)

out with the disconnect switch downstream of the inverter (grid side) open
and locked.

cables coming from MICRO inverters must be joined
inside a junction box.

A single line cable must then form the connection to
the distribution
Be particularly mindful of the dimensions of the line
cable. The grounding connection from the inverters
is obligatory.

grid.

must be made with securely-sealed Power-One components.

3.4.1 CHARACTERISTICS AND SIZING OF THE LINE CABLE

The line cable (not supplied from Power-One) runs between the junction box and the load
distribution panel.

The cross-section of the AC line conductor must be sized in order to prevent unwanted
disconnections of the inverter from the grid due to high impedance of the line that connects the
inverter to the power supply point. If the impedance is too high, it causes an increase in the AC
voltage that, on reaching the limit set by the country of installation, causes the inverter to switch
OFF.

length and cross section. In case of any doubt as to dimensions, refer to the
technical characteristics in the Appendix.

Page 43 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

The installation must be carried out with the equipment disconnected from the

Pay special attention and ensure not to reverse the phase with the neutral!

appropriate dimensions and insulation.

Part 3 Mounting and Wiring

3.5 WIRING OF AC CABLE

grid (power disconnect switch open).

Power-One AC cables from the MICRO inverters have four conductors with different colors to
identify the function of each conductor:

Table 3-2: Wiring of AC Cable

The installation technician is responsible for selecting a junction box with the

Close the junction box after the wiring is complete. Ensure that the seal is tight.

When connecting the inverter to the distribution grid, the configuration is made with the CDD. It is
essential to plan for the pertinent standards in the country.

Page 44 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Technical Manual

PART 4 OPERATIONS GUIDE

Page 45 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 4 Operations Guide

4.1 GENERAL CONDITIONS

One of the first rules for preventing damage to the equipment and to the operator is to have a
thorough knowledge of the operations.

It is necessary to read the AURORA CDD Instruction Manual before
commissioning the MICRO inverter.

Power-One CANNOT be held responsible for damage to the equipment or the operator if it is the
result of incompetence, insufficient qualifications or lack of training.

4.2 DISPLAY AND KEYPAD

The Power-One MICRO inverters associated with the CDD are controlled and monitored through
the CDD.

4.2.1 DESCRIPTION OF THE DISPLAY

The display for the CDD permits simultaneous monitoring of all the associated inverters. During
operation, the display behaves dynamically and cycles through the display of information.

The following information can be viewed by

menu

navigating in the

• Operating status of each MICRO inverter

and statistics.

• Operating status of the connection to the

internet/local

• Alarm messages and fault indicators.

The display offers user friendly and intuitive use
with the option of navigating through the
various menus by means of buttons on the side
of the

CDD.

:

network.

Page 46 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

The UP and DOWN buttons are used to move
around inside a menu or to increase/decrease

information on the CDD.

Part 4 Operations Guide

4.2.2 DESCRIPTION OF THE KEYPAD

On the right side of CDD device are four buttons used to control the various functions visualized on

display.

the

the settable values.

The ESC button returns the user to the previous
submenu when navigating.

The ENTER button is pressed to bring the user
to the desired submenu or to confirm an entered
value/parameter.

The UP and DOWN buttons pushed together will
open the main menus for STATISTICS, DATA
DISPLAY and DEFAULT SETTINGS.

Pressing any of these buttons during normal
operation (when the display reads GENERAL
DATA) will open the screen displaying

Page 47 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 4 Operations Guide

4.2.3 REMOTE MANAGEMENT

The CDD device is equipped with an Ethernet port and a Wi-Fi network interface controller to

a

connect to

system can be managed and monitored from a PC or Smartphone with internet access if the

The
device is registered at the Power-One portal (AURORA

local network or Internet.

VISION web portal).

Page 48 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Before checking the operation of the equipment, it is necessary to have a

specialized and qualified staff.

Part 4 Operations Guide

4.3 COMMISSIONING

thorough knowledge of the instruments described above and the functions that
have been enabled in the installation

The MICRO inverter operates automatically without the aid of a controller. The
operating

The interpretation or variation of some data is reserved exclusively for

The incoming voltage must not exceed the maximum values shown in the
technical data in order to avoid damaging the equipment. Consult the technical
data in the Appendix section of this manual for further details.

state is controlled through the instruments.

.

4.3.1 PRELIMINARY CHECKS

• When conducting the checks, ensure that the main AC disconnect (downstream from the

system) and any other possible isolator switches are disarmed.

• Ensure that all conductors and protective grounding points are connected.

• Check the position of all connection cables and the tightness of all nuts and terminals.

• Ensure that all electrical safeguards have been correctly installed.

4.3.2 SEQUENCE OF OPERATIONS

:

Start up the system as follows

• Ensure that the MICRO inverters and photovoltaic modules have been correctly installed.

• Arm the main AC disconnector (downstream from the system) and any other possible

isolator switches.

At this stage, we recommend not securing the CDD to the wall because the final installation position
might need to be re-evaluated based on the strength of the signal.

Page 49 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 4 Operations Guide

The steps to take for configuring the CDD, acquiring the MICRO inverters in the system and
registering at the “AURORA VISION” portal are described in the AURORA CDD Instruction Manual.
Please refer to the Operations Guide, Part 4, of the AURORA CDD Instruction Manual to complete
the commissioning of the MICRO inverter.

Upon completion of the commissioning, mount the CDD to the wall. Complete instructions for wall
mounting can be found in Part 3 of the AURORA CDD Instruction Manual.

.

Page 50 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Technical Manual

PART 5 TROUBLESHOOTING

Page 51 of 76 MICRO-0.25/0.3-I-OUTD-US-208-240 BCG.00612_AB

Alarm
Messages

Code
displayed

Cause

Solution

The error appears when the inverter input
current exceeds the set overcurrent

changes that may

generate input current surges into the

c) Faulty MICRO inverter

ly and no

b) It is necessary to verify that the

specifications are

c) If conditions a) and b) have been verified

he error persists, the malfunction may

be caused by an internal inverter fault

The error is generated when the voltage at

Over Voltage threshold. This may be

the event of highly abnormal grid voltage,

the grid voltage, the alarm may be caused
by internal inverter faults.

current exceeds the internal inverter alarm

a) Check that the grid voltage is stable,

maximum power generation of the PV

appropriate sizing of the line cable/s, and, if
correct, please contact your grid operator to

b) If no problems are found when checki ng
the grid voltage, the alarm may be caused
by internal inverter faults

Part 5 Troubleshooting Guide

5.1 ALARM MESSAGES GENERATED BY THE MICRO INVERTER

The equipment is capable of communicating errors/warnings via radio to the associated CDD
device. Any messages received and related codes can be checked on the display for the CDD device.

To understand and address warning (Wxxx) or error (Exxx) messages generated by the MICRO
inverters, in the installation and displayed on the CDD display, refer to the table shown below.

Table 5-1: Alarm messages and error codes displayed on CDD

Input OC E001

Vbulk OV E004

Output OC E006

threshold. This may be caused by:
a) sudden irradiance

MICRO inverter
b) PV module incompatible with the MICRO
inverter input characteristics

the ends of the bulk capacitors exceeds the

caused by:
a) Grid voltage too high
b) Internal inverter fault

The error appears when the inverter output

threshold.
This may be caused by:
a) High impedance grid with significant
voltage variations, even with small loads.
b) Internal inverter fault

a) The error occurs sporadical
action is required as the MICRO inverter will
automatically reset to normal operati on

photovoltaic module
compatible with the inverter.

and t

a) Check that the grid voltage is compatible
with the MICRO inverter specifications. In

please contact your grid operator to address
the problem.
b) If no problems are found when checking

mainly upon:

- loading with high current peak loads.

­system
If the grid voltage is unstable, verify the

address the problem.

Page 52 of 76 MICRO-0.25/0.3-I-OUTD-US-208-240 BCG.00612_AB

Alarm
Messages

Code
displayed

Cause

Solution

internal temperature recorded by the

the power that the inverter must supply, as

by the heat dissipated internally by its

re to observe the installation

a) Verify the installation conditions
(exposure to sunlight) and check that air

is not

obstructed, so as to permit cooling of the

readings (see the Internal Web Server
section in the CDD manual). If one of the

ue which is

40°C internal temp. reading
with 20°C effective ambient temperature),
the alarm may be due to internal inverter
causes.

The error is generated when a ground

current is detected in the DC

“Measuring the insulation resistance”

a) If the measured insulation resistance

a ground leakage that prevents the grid
connection of the inverter. In this case the

may be caused by internal inverter faults.

Ground Fault condition must be reset via
the Web Server.

the threshold set by the country of
installation’s applicable regulation. In any
case, the inverter will automatically try to
reconnect to the grid. This may be caused

a) Sporadic recurrence of this error is a

b) Systematic recurrence of this error may
be due to an inverter fault.

a) Verify the grid parameters and, if the grid
voltage is strongly distorted, please contact

tage is stable, the error may

In this case, the inverter will automatically
try to reconnect to the grid and no actions

b) If the grid voltage is stable, yet the error

tically persists, the malfunction may

Part 5 Troubleshooting Guide

OverTemp E014

Ground
fault

E018

High
inverter. This parameter depends in part on

the internal inverter temperature is affected

components. This may be caused by:
a) Failu
conditions
b) Internal inverter fault

leakage
section of the system. This may be caused
by:
a) PV module ground leakage
b) Internal inverter fault

flow to the MICRO inverter

device. Check that the ambient temperature
measured around the MICRO inverter does
not exceed the limits set in the technical
data.
b) Verify the MICRO inverter temperature

temperatures remains at a val
not compatible with the environmental con­ditions (e.g. -

See the “Verification of ground leakage” and

sections for information on how to perform
checks and measurements.

value is less than 1KΩ, the PV module has

DC
Injection

E023

The error is generated if the DC component
of the current supplied to the grid exceeds

by:

sign of large grid distortions or sudden
changes in irradiance.

PV module must be replaced.

b) If the measured value exceeds 1KΩ, try

connecting the MICRO inverter to a different
PV module. If the error persists, the alarm

To perform this test, the MICRO inverter

your grid operator to address the problem
If the grid vol
also be due to sudden irradiance variations.

are required to solve the problem.

systema
be caused by an internal inverter fault

Page 53 of 76 MICRO-0.25/0.3-I-OUTD-US-208-240 BCG.00612_AB

Alarm
Messages

Code
displayed

Cause

Solution

tialization and is caused by the initialization
of communication between the CDD and

be due to an inverter fault.

a) The alarm will automatically reset upon

b) If the error systematically persists, the

ion may be caused by an internal

inverter fault

The alarm is generated when the grid
standard (selected on the CDD during
installation) has not been correctly set on

b) poor irradiance while setting the grid

s are directly

iance may cause

a) Verify on the Internal Web Server (as
described in the CDD manual), the radio

(values above 60% indicate good

reception). If the quality of the received

configure the installation,
otherwise consider installing the CDD
device in a different position to ensure

ditions, in order to

of the

and to prevent the risk of

downs due to insufficient input voltage

generated by the PV module.

version. Firmware updates are performed
via the Internal Web Server (see the CDD
manual), with the software package
obtained from Power-One Service

This alarm is displayed when the input
voltage generated at the PV generator is
outside the allowed range given in the

e present on

characteristics are compatible with the

d) If the above checks have yielded positive
results, yet the error persists, the

inverter.

grid parameters lie outside the permitted
range set by the country of installation’s
grid standard. The error code will be

(UF) Grid frequency below the set lower

(OF) Grid frequency above the set upper
limit

s, this may be

If the alarm is generated at multiple
inverters in the installation, check the grid
voltage for instabilities in any of the 4
parameters monitored by the inverter. If

malous values are detected, verify the

correct sizing, please contact your grid

Part 5 Troubleshooting Guide

Internal
Error

Country
Mismatch

Country
Not Comp

E024

E050

E051

a) The alarm may occur during inverter ini-

the MICRO inverters.
b) Systematic occurrence of this error may

the MICRO inverters. This may be caused
by:
a) communication problems while setting
the grid standard for the MICRO inverter
from the CDD:

standard for the MICRO inverter from the
CDD: MICRO inverter
supplied by the voltage generated at the
panel, and poor irrad
inverter shut downs

The set grid standard is not compatible with
the firmware installed on the MICRO
inverter. This condition may be generated if
a MICRO inverter is replaced.

connection of the inverter to the grid, and no
actions are required to solve the problem.

malfunct

communication quality on each MICRO
inverter

signal is good re-

better radio signal quality.
b) System configuration must be carried out
in good irradiance con
guarantee the correct operation
MICRO inverter
shut-

The firmware in the MICRO inverter/s in the
installation must be updated to a compatible

Vpanel
Problem

Grid Fail W003

W001

technical data. This may be caused by:
a) Poor irradiance
b) Possible shadows that may darken the
module during part of the day.
b) PV module incompatible with the MICRO
inverter input parameters
d) Internal inverter fault

This alarm is generated when one or more

followed by a suffix in brackets indicating
the grid parameter out of range:
(UV) Grid voltage below the set lower limit
(OV) Grid voltage above the set upper limit

limit

a) Wait for appropriate irradiance to
guarantee correct operation of the inverter
b) Verify that no shadows ar
the PV module when the error is generated
c) Verify that the PV module voltage

inverter input specifications.

malfunction may be caused by the MICRO

If the error is generated only on one of the
installation MICRO inverter
due to an inverter fault.

ano
sizing of the AC line conductors. In case of

operator to address the problem.

Page 54 of 76 MICRO-0.25/0.3-I-OUTD-US-208-240 BCG.00612_AB

Alarm
Messages

Code
displayed

Cause

Solution

he alarm is generated when the CDD

for more than 5 minutes.

Consider a new installation position that

nication between the

the CDD Internal Web Server to verify the
signal quality (refer to the CDD manual for
information on the Internal Web Server)

is generated when the CDD

Consider a new installation position that
ensures better communication between the

CDD Internal Web Server to verify the
signal quality (refer to the CDD manual for
information on the Internal Web Server)

The alarm is generated when an external
shutdown command has been sent to the

Part 5 Troubleshooting Guide

Vbulk UV W011

Comm
warning

Comm
fault

Remote
Off

W025

W005

E035

Internal fault of the booster circuit inverter Contact Power-One Service.

T
device does not receive messages from the
MICRO inverter
This may be caused by non-optimal
positioning of the CDD.

The alarm
device does not receive messages from the
MICRO inverter for more than 15 minutes.
This may be caused by non-optimal
positioning of the CDD.

MICRO inverter.

ensures better commu
CDD device and the MICRO inverters. Use

CDD device and the MICRO inverters. Use
the

Disable the Remote Off com mand.

Page 55 of 76 MICRO-0.25/0.3-I-OUTD-US-208-240 BCG.00612_AB
Part 5 Troubleshooting Guide

5.2 VERIFICATION OF GROUND LEAKAGE

In the presence of anomalies or report of ground fault, there may be a ground leakage from the
photovoltaic

module.

To check this, measure the voltage between the positive pole and ground and between the negative
pole and ground

using a voltmeter

5.2.1 BEHAVIOR OF A SYSTEM WITHOUT LEAKAGE

Due to the capacitive effect of the photovoltaic module, during the first moments that the voltmeter
is connected between one of the two poles and ground, it will measure a voltage of about Voc/2,
which will tend to stabilize to around 0V if there is no ground leakage, as shown in the graph below:

.

The internal resistance of
the voltmeter tends to
zero the voltage present
on the PV generator due
to the capacitive

How to make the measurement:

Positive pole Vs Ground Negative pole Vs Ground

effect

Page 56 of 76 MICRO-0.25/0.3-I-OUTD-US-208-240 BCG.00612_AB
Part 5 Troubleshooting Guide

5.2.2 BEHAVIOR OF A SYSTEM WITH LEAKAGE

If the voltage measured between one of the two poles and ground does not tend to 0V and stabilizes
on a value, there is a ground leakage from the photovoltaic module.

Example: When the measurement is made between positive pole and ground, on a photovoltaic
module with Voc=37V, a voltage of 7V is measured.

5.3 MEASURING THE INSULATION RESISTANCE OF PHOTOVOLTAIC

MODULE

To measure the insulation resistance of the photovoltaic module compared to ground, the two poles
of the PV generator must be short-circuited (using a suitably sized selector), and verify that the
chassis of the module itself is referred to ground (of the inverter).

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Part 5 Troubleshooting Guide

Once the short-circuit has been made, measure the insulation resistance (Riso) using a
megohmmeter positioned between the two shorted poles and ground (of the inverter).

If the measured insulation resistance is less than 1Kohm the inverter does not connect to the grid
due to a low insulation of photovoltaic module respect to ground.

The insulation resistance is affected by the environmental conditions the photovoltaic module
is in (E.g.: photovoltaic module wet from dump or rain); therefore, the measurement must be
made immediately after the anomaly.

Page 58 of 76 MICRO-0.25/0.3-I-OUTD-US-208-240 BCG.00612_AB

AURORA model?

What signals are shown on the
display?

Part 5 Troubleshooting Guide

5.4 THE POWER-0NE SERVICE CALL

Call Power-One Technical Support at 1-877-261-1374 and provide the following information.


 Serial number?
 Week of production?


NOTE: information above is available from the CCD.

Additional helpful information when troubleshooting with the Power-One Technical Service
Engineers:

• Provide a brief description of the fault.

• Information on the photovoltaic module

• Brand and model of photovoltaic modules

• Identify the system structure:

o Maximum voltage and current values
o Can the fault be reproduced? If so, how?
o Is the fault cyclical in nature? If so, how often?
o Was the fault apparent at the time of installation?
o If so, has it got worse?

Describe the atmospheric conditions at the time the fault appears/appeared.

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Technical Manual

PART 6 MAINTENANCE GUIDE

Page 60 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Maintenance operations must be carried out with the equipment disconnected

isolated, unless otherwise indicated.

For cleaning, DO NOT use rags made of filamentary material or corrosive

spare parts.

It is recommended that maintenance operations be only performed by

Part 6 Maintenance Guide

6.1 GENERAL CONDITIONS

Maintenance operations must be carried out by authorized personnel assigned to carry out this
work.

from the grid (power switch open) and the photovoltaic modules obscured or

products that may corrode parts of the equipment or generate electrostatic
charges.
Avoid temporary repairs. All repairs should be carried out using only genuine

The maintenance technician is under obligation to promptly report any anomalies.

DO NOT allow the equipment to be used if problems of any kind are found, and restore the normal
conditions correctly or otherwise make sure that this is done.

Always use the personal protective equipment provided by the employer and comply with the
safety conditions in Part 1, Introduction and Safety.

During normal operation, check that the environmental and logistic conditions (described in Part 1
of this manual) are correct. Make sure that the conditions have not changed over time and that the
equipment is not exposed to adverse weather conditions and has not been covered with foreign
bodies.

6.1.1 ROUTINE MAINTENANCE

Routine maintenance, although not mandatory, is recommended to maintain efficient operation
of the PV installation.

qualified personnel or Power-One personnel (under a servicing contract).

The maintenance schedule may vary depending on the environmental
conditions of the installation site

Page 61 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB

Do not attempt to dismantle the equipment or make any internal repairs!

Part 6 Maintenance Guide

Table 6- 1: Routine Maintenance

With a view to preserving the integrity of their safety and insulation, AURORA
MICRO inverters are not designed to allow internal repairs.

The AC output wiring harness (AC drop cable on the MICRO inverter) cannot be
replaced. If the cord is damaged the equipment should be scrapped.

Any maintenance or replacement of the device
could require dismounting the photovoltaic
module mounted on top of the MICRO inverter.

This condition must be accounted for during
installation, ensuring that the safety distances
are correct for normal control and
maintenance operations.

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Part 6 Maintenance Guide

6.2 STORAGE AND DISMANTLING

6.2.1 STORAGE OF THE EQUIPMENT OR PROLONGED STOP

If the equipment is not used immediately or is stored for long periods, check that it is correctly
packed. The equipment must be stored in well-ventilated indoor

the

characteristics that might damage

Restarting after a long or prolonged stop requires a check and, in some cases, the removal of
oxidation and dust that will also have settled inside the equipment if not suitably protected.

components of the equipment.

6.2.2 DISMANTLING, DECOMMISSIONING AND DISPOSAL

Power-One CANNOT be held responsible for disposal of the equipment: displays, cables, batteries,
accumulators, etc.; therefore, the customer must dispose of these substances,
harmful to the environment, in accordance with the regulations in force in the country o
installation.

If the equipment is dismantled, you must adhere to the regulations in force in the country of
destination, and in any case avoid causing any kind of
listed below.

Table 6- 2: Disposal of Components

pollution in order to dispose of the products

areas that do not have

which are potentially

f

Dispose of the various types of materials that the parts of the equipment consist of in dumps
that are suitable for the purpose.

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Technical Manual

PART 7 APPENDIX

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Part 7 Appendix

7.1 TECHNICAL DATA

Page 65 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 7 Appendix

7.1.1 EFFICIENCY CURVES

Graphs of the efficiency curves of all the models of inverter described in this manual are shown
below. The efficiency curves are linked to technical parameters that are continually being
developed and improved and should therefore is considered approximate.

Figure 7-1: MICRO-0.25-I-OUTD-208/240 efficiency curve

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Part 7 Appendix

Figure 7-2: MICRO-0.3-I-OUTD-208/240 efficiency curve

7.1.2 POWER DERATING

In order to allow inverter operation in safe thermal and electrical conditions, the unit automatically
reduces the value of the power fed into the grid. Power derating can take place due to adverse
environmental conditions or due to unsuitable input voltage values.

The conditions for power reduction due to environmental conditions and input voltage can also
occur at the same time, but the power reduction will always relate to the lower value measured.

7.1.2.1 Power Reduction Due To Environmental Condition

The power reduction value and the inverter temperature at which it occurs depend on the
ambient temperature and on many operating parameters. Example: input voltage, grid voltage
and power available from the photovoltaic field.
The inverter can therefore reduce the power during certain periods of the day and according to
the value of these parameters.
In any case, the inverter guarantees the maximum output power even at high temperatures,
provided the sun is not shining directly on it.

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Part 7 Appendix

Figure 7-3: MICRO-0.25-I-OUTD-208/240 temperature derating curve

Figure 7-4: MICRO-0.3-I-OUTD-208/240 temperature derating curve

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Part 7 Appendix

7.1.2.2 Power Reduction Due To the Input Voltage

The graphs show the automatic reduction of supplied power when input voltage values are too high
or too low.

Figure 7-5: MICRO-0.25-I-OUTD-208/240 voltage derating curve

@ Tamb up to 65⁰C

Figure 7-6: MICRO-0.25-I-OUTD-208/240 voltage derating curve

@ Tamb up to 75⁰C

Page 69 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 7 Appendix

Figure 7-7: MICRO-0.3-I-OUTD-208/240 voltage derating curve

@ Tamb up to 65⁰C

Figure 7-8: MICRO-0.3-I-OUTD-208/240 voltage derating curve

@ Tamb up to 75⁰C

Page 70 of 76 MICRO-0.25/0.3-I-OUTD-US-208/240 BCG.00612_AB
Part 7 Appendix

7.1.1 BLOCK WIRING DIAGRAM

The diagram below summarizes the layout of the MICRO inverter. The main blocks are the DC-DC
input converter (the “boost” section) and the DC-AC output inverter. Both work at a high switching
frequency, are small and relatively light.

The inverter is equipped with a single input converter with Maximum Power Point Tracking
(MPPT) to which it is possible to connect a single photovoltaic module. This means that the
modules connected to the MICRO inverters could be installed in different positions and
orientations. This inverter is equipped with a high-frequency transformer, in other words with
galvanic isolation of the primary (DC side) from the secondary (AC side), while maintaining very
high performance in terms of output and energy export. This type of circuit allows for the
grounding of the positive input pole.

The inverter is controlled by two independent DSPs (Digital Signal Processors) and a central
microprocessor. The connection to the power grid is thus kept under control by two independent
monitors, in full compliance with the electric field norms both for power supply to the systems as
well as security.

The wireless communication system inside the MICRO inverter transmits the information to the
CDD device that analyzes and manages all system data. All this guarantees optimal operation of the
entire unit and high efficiency in all insolation and load conditions, always in full compliance with
the relevant directives, standards and provisions.

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Part 7 Appendix

Figure 7-9: Topographic Diagram

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Part 7 Appendix

Figure 7-10: Wiring diagram – 208Vac three phase *

*IMPORTANT: If several Aurora MICRO inverters are installed in a three-phase AC GRID, it is recommended to
distribute the inverters between the phases in order to reduce the power unbalances between the phases. Always
refer to the local standards.

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Part 7 Appendix

Figure 7-11: Wiring diagram – 240Vac split phase

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Part 7 Appendix

7.1.1 FUNCTIONALITY OF THE EQUIPMENT

Data transmission

The MICRO inverters are monitored remotely through an advanced communications system based
on a wireless connection and the CDD device. In addition to local monitoring of the system, it is
possible to have remote data visualization through an internet access to Power-One’s AURORA®
VISION web

portal.

and control

Single photovoltaic module management benefit

There are many advantages of having each MICRO inverter monitor a single photovoltaic
Capability of viewing each module’s production
Possibility of controlling when to clean each module, as necessary
Ease of service interventions from the possibility of singling out individual modules or inverter that
are down.
Preservation of production even if there is a malfunctioning module or inverter

module:

7.1.2 PROTECTIVE DEVICES

7.1.2.1 Anti-Islanding

In accordance with required national standards and laws, in the event of a local grid outage by the
utility, or when the grid equipment is switched OFF for maintenance operations, the inverter must
be physically and safely disconnected, to ensure protection of personnel working on the grid. To
prevent possible islanding, the inverter has an automatic protective disconnection system called
“Anti-Islanding”.

7.1.2.2 Ground fault in the photovoltaic modules

An advanced ground fault protection circuit continuously monitors the ground connection and
disconnects the inverter if a ground fault occurs, indicating this condition by means of the red GFI
LED on the LED panel.

7.1.2.3 Protective devices

The inverter is equipped with additional protective devices to facilitate safe operation. These
protective devices include:
Continuous monitoring of the grid voltage to ensure the voltage and frequency values stay within
operating limits;
Control of internal temperatures to automatically limit the power if necessary to ensure the unit
does not overheat (derating).

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Part 7 Appendix

7.2 TEMPLATE FOR MAP OF MICRO INVERTER INSTALLATION

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Part 7 Appendix

7.3 INDEX OF TABLES AND FIGURES

Table 1-1: Inverter models available............................................................................................................................... 7

Table 1-2: Product nameplate ............................................................................................................................................ 7

Table 1-3: Voltage and frequency trip limits ............................................................................................................. 12

Figure 1-1: Safety label location ...................................................................................................................................... 18

Figure 1-2: Identification label for adhering to system map ............................................................................... 19

Table 2-1: List of components supplied ....................................................................................................................... 23

Figure 2-1: Overall dimensions of MICRO inverter ................................................................................................. 24

Figure 2-2: Installation position of MICRO underneath PV module ................................................................. 26

Figure 2-3: Installation orientation of MICRO considering distances ............................................................. 27

Figure 2-4: Horizontal orientation of the photovoltaic modules ....................................................................... 28

Figure 2-5: Vertical orientation of the photovoltaic modules ............................................................................. 29

Figure 3-1: Graphical representation of assembly instructions ........................................................................ 31

Figure 3-2: Equipment grounding conductor coupling all the inverters ....................................................... 33

Figure 3-3: Configurations for grounding the MICRO inverters ........................................................................ 34

Figure 3-4: Disconnection of the MICRO inverter AC cable ................................................................................. 39

Figure 3-5: Removing the AC trunk plug cap ............................................................................................................. 39

Table 3-1: Overcurrent device recommended characteristics ........................................................................... 40

Table 3-2: Wiring of AC Cable ........................................................................................................................................... 43

Table 5-1: Alarm messages and error codes displayed on CDD ......................................................................... 51

Table 6- 1: Routine Maintenance .................................................................................................................................... 61

Table 6- 2: Disposal of Components .............................................................................................................................. 62

Figure 7-1: MICRO-0.25-I-OUTD-208/240 efficiency curve ................................................................................ 65

Figure 7-2: MICRO-0.3-I-OUTD-208/240 efficiency curve .................................................................................. 66

Figure 7-3: MICRO-0.25-I-OUTD-208/240 temperature derating curve ....................................................... 67

Figure 7-4: MICRO-0.3-I-OUTD-208/240 temperature derating curve .......................................................... 67

Figure 7-5: MICRO-0.25-I-OUTD-208/240 voltage derating curve @ Tamb up to 65⁰C ........................ 68

Figure 7-6: MICRO-0.25-I-OUTD-208/240 voltage derating curve @ Tamb up to 75⁰C ......................... 68

Figure 7-7: MICRO-0.3-I-OUTD-208/240 voltage derating curve @ Tamb up to 65⁰C ............................ 69

Figure 7-8: MICRO-0.3-I-OUTD-208/240 voltage derating curve @ Tamb up to 75⁰C ............................ 69

Figure 7-9: Topographic Diagram .................................................................................................................................. 71

Figure 7-10: Wiring diagram – 208Vac three phase * ............................................................................................ 72

Figure 7-11: Wiring diagram – 240Vac split phase ................................................................................................. 73

Release NA1.0 - Aurora® is a trademark by Power-One - Product is subject to technical improvements

www.p ower-one.com

Aurora® Power Service USA 877-261-1374

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®

Power Service France 00 800 00 28 76 72

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®

Power Service Germany 0800-2200211

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®

Power Service Italy 00 800 00 28 76 72

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Power Service Spain 00 800 00 28 76 72

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Power Service Middle East 00 800 00 28 76 72

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Power Service Australia [phone]

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