Webinar Training 041609

Micro-Inverter System
Installation Recommendations
Jeff Laughy
Applications Engineer

Enphase Micro-Inverter

One Micro-inverter per PV Module

Enphase Energy Proprietary & Confidential [ 2 ]

Photovoltaic Cell

Building Block of PV Modules

Each cell produces .5 Vdc

Monocrystalline cell - a thin slice
cut from a single crystal of Monocrystalline Cell

silicon, highest efficiency 17%

Polycrystalline cell – liquid silicon
is poured into blocks, then
sliced, more cost efficient, lower
efficiency, 15%
Polycrystalline Cell


Typical Configurations

54 cells in series

60 cells in series

72 cells in series produce enough
voltage to charge 24V batteries
(24 volt nominal)

84 cells in series


Maximum Power Point

Short Circuit Current Isc 5.75 A
Voltage varies with Open Circuit Voltage Voc 47.7 V
Max Power Current Imp 5.25 A
Temperature Max Power Voltage Vmp 40.0 V

Current varies with
Irradiance

Power equals
Voltage x Current
5.25 A x 40.0 V
= 210 Watts


Series String

Current is equal in a series circuit, unshaded string would
produce 5.25 amps x 40 volts = 210 watts per module,
5 modules at full power = 1050 watts per string.


Series String Shaded

Lowest performing module determines the current for the
string, a single shaded module could reduce the current to 2
amps

2 amps x 40 volts = 80 watts per module,
5 modules at 80 watts = 400 watts per string, 38% of max.


Micro-inverter Branch

In the micro-inverter branch only one modules current
reduced to 2 amps

1 module at 80 watts
4 modules at 210 watts = 840 watts
Power produced per branch = 920 watts, 87% of max.


Burst Mode

BURSTING STORING BURSTING STORING BURSTING

[9]

Roof Top Array Temperatures



Location Data

AC Power output 124 Watts

Ambient Air Temp (Ta) 113.56 °F

Metal Roof Surface Temp (Troof) 147.42 °F

Module Glass Temp (Tframe) 125.10 °F

Under Module Air Temp (Tamb) 110.10 °F

Micro-Inverter Internal Temp (Tinv) 120.07 °F


Micro-inverter Technical Data
60 and 72 Cell Modules, 240 Vac

 Input Data (DC)
–  Recommended Input Power (STC) 230 Watts
–  Peak Power Tracking Voltage 22V – 40V
–  Maximum DC Voltage 54V
–  Positive Ground

 Output Data (AC)
–  Maximum Output Power 190 Watts
–  Nominal Output Current .80 Amps
–  Maximum number of inverters
per 15 amp branch circuit 15


Distribution Panel Connections
240 Vac Single Phase

Voltage Drop Considerations, 240 Vac

The table below provides recommendations for wire size
from the junction box at the beginning of the Micro-inverter
branch to the main load center based on distance.

External Branch (Home Run) Wiring Maximum Distance in Feet

Micro-Inverters per Branch

Wire 7 8 9 10 11 12 13 14 15

14 AWG 126 103 84 68 54 42 31 21 12

12 AWG 199 163 133 107 86 66 49 33 19

10 AWG 318 260 212 171 137 106 78 53 30

8 AWG 507 414 337 273 218 169 125 84 48

6 AWG 804 656 535 433 345 267 198 135 76


Micro-inverter Technical Data,
60 and 72 Cell Modules, 208 Vac

 Input Data (DC)
–  Recommended Input Power (STC) 230 Watts
–  Peak Power Tracking Voltage 22V – 40V
–  Maximum Input Voltage 54V
–  Positive Ground

 Output Data (AC)
–  Maximum Output Power 190 Watts
–  Nominal Output Current .92 Amps
–  Maximum number of inverters
per 15 amp branch circuit 21


208 Vac Three Phase


Voltage Drop Considerations, 208 Vac

The table below provides recommendations for wire size
from the junction box at the beginning of the Micro-inverter
branch to the main load center based on distance. The table
is in increments of 3 inverters, always round up to the next
increment.
External Branch (Home Run) Wiring Maximum Distance in Feet

Micro-Inverters per Branch

Wire 6 9 12 15 18 21

14 AWG 479 303 209 148 104 69

12 AWG 759 481 332 235 165 109

10 AWG 1212 768 531 376 263 174

8 AWG 1932 1224 846 599 419 277

6 AWG 3061 1939 1340 950 664 438


208 Vac Three Phase with LCF


The Enphase Micro-Inverter System
Site Installed Components

Micro-Inverters
One inverter per-module

Communication Gateway
Each gateway supports 250 inverters

AC Interconnect Cable, End Cap
One per 15 amp branch circuit

Junction Box Adapter Plate
One per 15 amp branch circuit

Branch Circuit Cable Layout

  Inverter branches can be routed horizontally,
vertically, or a combination of both directions.

  Standard Inverter cable lengths are 6 ft, extension cables
are available in 6 ft, 12 ft and 20 ft lengths.

Micro-Inverter Installation

Step 1 - Junction Box Adapter Plate
Step 2 - Attaching the Micro-Inverter
Step 3 - Connecting the Circuit Cables
Step 4 - Grounding Conductor Connection
Step 5 - Installation Map
Step 6 - Module Connection

Indicates a fact or feature very important for the
safety of the user.

Indicates an Enphase recommendation or best practice.

Step

Step

Step

Step

Step

Step
1 2 3 4 5 6

Mount an outdoor rated
junction box to the adapter
plate.

This junction box is used to
connect the inverter pigtail
to the cable or conduit that
has been run to the main
load center.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6

Install the Enphase
adapter plate and
junction box assembly
to the module racking.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6

Connect the Enphase
AC interconnect
cable to the junction
box.

Standard Inverter
pigtail length is 6 ft,
longer pigtails are
available in 12 ft
and 20 ft lengths.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Attaching the Micro-inverter

Mark the approximate
centers of each PV
module on the racking
system. (module width
plus 1” for clips)

Avoid aligning
the Inverter with the
Module junction box.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Attaching the Micro-inverter

Attach the Enphase
Micro-inverters at
the module centers
using the racking
manufacturer’s
hardware.

Orient the inverter so
that the inverter
connector with male pins
is toward the load center.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Connecting the Circuit Cables

Connect the first
Enphase Micro-inverter
to the Enphase AC
interconnect cable.

Orient the inverter
so the male connector
is toward the junction
box.

Step

Step

Step

Step

Step

Step
1 2 3 4 5 6

Connect the
remaining Enphase
Micro- Inverters.
Ensure that the
connectors are
securely locked.

Use cable ties to secure
the AC cables to the
racking.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6

Do not exceed the
maximum number of
Enphase Micro-inverters
per branch circuit listed
on the product label.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6

Attach the included
protective end cap
onto the unused
connector of the
last Enphase Micro-
inverter.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Grounding the Conductor Connection

Connect the grounding
conductor to each
Enphase Micro-inverter
in the location marked
“Grounding Electrode
Terminal”.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Grounding Conductor Connection

Route a single grounding
conductor through all the
inverters.

Connect a short length of
Ground wire to each module

Separate conductors
for the modules and
inverters may be installed.

Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Installation Map

Peel one of the two
labels from each
Enphase Micro-
inverters and place
the label on the
Enphase installation
map to show the
relative physical
location of the
modules.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Module Connections

Connect the PV
modules to the
Enphase Micro-
inverters.


DC Disconnection Procedure

Do not disconnect module connectors under
load.

Disconnecting AC first will eliminate the DC
current prior to disconnecting the module.

Individual modules could also be covered
prior to disconnecting cables during daylight hours


Energy Management Unit Installation

Step 1 - Power Connection
Step 2 - Network Connection
Step 3 - EMU Startup
Step 4 - Enlighten Registration
Step 5 - Fax the Inverter info
Step 6 – The Enlighten web site

Indicates a fact or feature very important for
the safety of the user.
Indicates an Enphase recommendation or
best practice.

Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Power Connection

Connect the power cord
to the EMU power inlet,
then plug the power
cable into a power outlet
somewhere near your
internet router.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Power Connection

Do not plug the EMU
into a power strip or
Uninterruptable Power
Supply (UPS), the surge
suppression or filtering
components of the power
strip could disrupt the EMU
power line communications.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Network Connection

Plug the provided CAT5/6
twisted pair Ethernet
patch cable into the RJ45
on the EMU.

Plug the other end
of the Ethernet
patch cable into the
broadband router.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
EMU Startup

It takes less than 5 minutes
for the EMU to boot.
You know that it has
booted when it displays
An IP address, and
shows “+WEB” both in the
onboard LCD window.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
EMU Startup

A newly installed EMU will
scan for 1 week.

To restart a scan or perform
a communication check once
the EMU has booted, press
and hold the button labeled
“SCAN” on the front for 2
seconds. This will enable
The LCD panel menu.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
EMU LCD Panel Menu

Continue holding the “SCAN”
button until the desired menu
option appears.
Release the “SCAN” button to
select a menu option.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
EMU Startup
Device Scan
During a device scan the display shows the
following:

Communication Check
After a communication Check the display shows
the following


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
EMU Startup
192.168.2.140
(or whatever the local IP address is)
+WEB
(indicating that it made a connection to the internet)
(n)W
(indicating the present power production in watts)
(n)kWh
(indicating the lifetime watt hours reported to this EMU)
(n)
(indicating the number of Micro-Inverters reporting to the
EMU)


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Enlighten Registration
Register the EMU with the Enlighten web site by
entering the EMU serial number and the site
information.


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
Fax the Micro-inverter Information

Fax the completed
installation map from
the Micro-inverter
installation to Enphase at
707-763-0784.


Direct Connection to Envoy


Step

Step

Step

Step

Step

Step
1 2 3 4 5 6
The EnlightenTM Website

Once the website is
configured, energy data
will be displayed on the
Enphase Enlighten™
website on a per PCU,
per module basis.


Branch Circuit Calculations, 240 Vac

 Circuit Current Calculation
–  Maximum Output Power = 190 Watts AC
–  190 W ÷ 240 V = .80 Amps
–  .80 x 15 inverters = 12.0 amps / branch

 Overcurrent Protection Calculation
–  12.0 x 1.25 = 15.0 Amps

 Conclusions:
–  Install 1 to 15 Inverters per branch, up to 2850 Watts
–  Minimum 2 Pole 15 Amp circuit breaker, 14 AWG wire
size.


Branch Circuit Calculations, 208 Vac

 Circuit Current Calculation
–  Maximum Output Power = 190 Watts AC
–  190 W ÷ 208 V = .92 Amps
–  .92x 7 inverters per phase = 6.44 amps per phase
–  6.44 x 1.73 = 11.14 amps per leg

 Overcurrent Protection Calculation
–  11.14 x 1.25 = 13.92 Amps

 Conclusions:
–  Install 1 to 21 inverters per branch, up to 3990 Watts
–  Minimum 3 Pole 15 Amp circuit breaker, 14 AWG wire
size.

Performance Monitoring Reporting Service

Enphase Energy is an approved PMRS provider, the Energy Tracking
LLC, Web Enabled Meter communicates directly with the Enphase EMU.
The metered data is then forwarded to the participating utility.


Enlighten login, Presentation downloads

demo@enphaseenergy.com

Password - microinverter

Downloads of presentations

http://www.box.net/shared/r7vj5pje3e


Webinar Training 041609

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