OutBack Power FLEXmax 100 User manual

FLEXmax 100
Charge Controller
Owner’s Manual

About OutBack Power Technologies
OutBack Power Technologies is a leader in advanced energy conversion technology. OutBack products
include true sine wave inverter/chargers, maximum power point tracking charge controllers, and system
communication components, as well as circuit breakers, batteries, accessories, and assembled systems.
Grid/Hybrid™
As a leader in off-grid energy systems, which are designed around energy storage, OutBack Power is an
innovator in Grid/Hybrid system technology which provides the best of both worlds: grid-tied system
savings during normal or daylight operation, and off-grid independence during peak energy times or in the
event of a power outage or an emergency. Grid/Hybrid systems have the intelligence, agility, and
interoperability to operate in multiple energy modes quickly, efficiently, and seamlessly, in order to deliver
clean, continuous and reliable power to residential and commercial users while maintaining grid stability.
Contact Information
Address: Corporate Headquarters
17825 – 59th Avenue N.E.
Suite B
Arlington, WA 98223 USA
European Office
Hansastrasse 8
D-91126
Schwabach, Germany
Website: http://www.outbackpower.com
Disclaimer
UNLESS SPECIFICALLY AGREED TO IN WRITING, OUTBACK POWER TECHNOLOGIES:
(a) MAKES NO WARRANTY AS TO THE ACCURACY, SUFFICIENCY OR SUITABILITY OF ANY
TECHNICAL OR OTHER INFORMATION PROVIDED IN ITS MANUALS OR OTHER
DOCUMENTATION.
(b) ASSUMES NO RESPONSIBILITY OR LIABILITY FOR LOSS OR DAMAGE, WHETHER DIRECT,
INDIRECT, CONSEQUENTIAL OR INCIDENTAL, WHICH MIGHT ARISE OUT OF THE USE OF SUCH
INFORMATION. THE USE OF ANY SUCH INFORMATION WILL BE ENTIRELY AT THE USER’S RISK.
OutBack Power Technologies cannot be responsible for system failure, damages, or injury resulting from
improper installation of their products.
Notice of Copyright
FLEXmax 100 Charge Controller Owner’s Manual © 2017 by OutBack Power Technologies. All Rights
Reserved.
Trademarks
OutBack Power, the OutBack Power logo, OPTICS RE, and Grid/Hybrid are trademarks owned and used
by OutBack Power Technologies, Inc. The ALPHA logo and the phrase “member of the Alpha Group” are
trademarks owned and used by Alpha Technologies Inc. These trademarks may be registered in the
United States and other countries.
Date and Revision
December 2017, Revision A
Part Number
900-0209-01-00 Rev A

900-0209-01-00 Rev A 3
Table of Contents
Important Safety Instructions ...................................................................................... 6
Symbols Used........................................................................................................................................... 6
General Safety.......................................................................................................................................... 6
Introduction ................................................................................................................... 7
Audience................................................................................................................................................... 7
Features.................................................................................................................................................... 7
Firmware................................................................................................................................................... 7
Components and Accessories.................................................................................................................. 8
Battery Types ....................................................................................................................................... 8
Installation ..................................................................................................................... 9
Standards and Requirements................................................................................................................... 9
Dimensions........................................................................................................................................... 9
Installation............................................................................................................................................... 10
Installing the Fan ................................................................................................................................ 10
Mounting the Charge Controller ......................................................................................................... 10
Keyhole Slot Mount ........................................................................................................................ 11
Bracket Mount ................................................................................................................................ 12
Wiring...................................................................................................................................................... 13
Grounding........................................................................................................................................... 13
Negative-Ground Systems............................................................................................................. 13
Positive-Ground Systems .............................................................................................................. 14
Ground Fault Detection and Interruption (GFDI) ........................................................................... 15
External GFDI ............................................................................................................................ 15
Wiring Size and Requirements........................................................................................................... 16
Circuit Breaker Size and Requirements ............................................................................................. 16
Physical Requirements and Conduit .................................................................................................. 17
PV and Battery Terminals .................................................................................................................. 17
Accessory Terminals and Ports.......................................................................................................... 18
Reset Button .................................................................................................................................. 18
HUB Port ........................................................................................................................................ 18
Device and LAN Ports.................................................................................................................... 18
Remote Temperature Sensor Port................................................................................................. 18
SD Card ......................................................................................................................................... 19
Fan Connector ............................................................................................................................... 19
Accessory Terminal Block.............................................................................................................. 19
Rapid Shutdown Terminals........................................................................................................ 19
AUX Terminals........................................................................................................................... 19
Battery Sense Terminals ........................................................................................................... 21
Wiring Diagrams ................................................................................................................................. 22
Wiring the Rapid Shutdown Terminals........................................................................................... 24
Power Up ................................................................................................................................................ 26
Setting the Nominal Voltage............................................................................................................... 26
Initial Operation .................................................................................................................................. 27
Resetting to Factory Defaults ............................................................................................................. 27

Table of Contents
4900-0209-01-00 Rev A
Status and Information ............................................................................................... 29
LED Indicators ........................................................................................................................................ 29
Modes of Operation........................................................................................................................ 31
Bulk ............................................................................................................................................ 31
Absorb........................................................................................................................................ 32
Floating ...................................................................................................................................... 33
EQ.............................................................................................................................................. 33
Silent .......................................................................................................................................... 34
MATE3s System Display ........................................................................................................................ 35
Battery Status Indicators .................................................................................................................... 35
Charger Indicator................................................................................................................................ 35
Charge Controller Soft Key ................................................................................................................ 36
Status Screen................................................................................................................................. 36
Stats Screen ....................................................................................................................................... 37
Error Screen ....................................................................................................................................... 38
Temps Screen .................................................................................................................................... 38
DataLog Screen.................................................................................................................................. 39
Graph Screens ................................................................................................................................... 40
Programming the FLEXmax 100 ................................................................................ 41
Menu Structure in the MATE3s .............................................................................................................. 41
Charge Controller Settings ..................................................................................................................... 42
Charger............................................................................................................................................... 42
MPPT.................................................................................................................................................. 43
Temperature Compensation............................................................................................................... 43
Battery Equalize ................................................................................................................................. 44
Grid-Tie Mode..................................................................................................................................... 44
Auxiliary Output .................................................................................................................................. 45
Auxiliary Mode Screens ................................................................................................................. 45
Calibrate ............................................................................................................................................. 50
Reset Charge Controller to Factory Defaults ..................................................................................... 50
Firmware Revision ......................................................................................................................... 51
Device Data Logs ................................................................................................................................... 51
Saving Data Logs for the FLEXmax 100 ............................................................................................ 51
Data Log File Format ................................................................................................................. 52
Updating the Firmware ........................................................................................................................... 53
Using MATE3s.................................................................................................................................... 53
Without MATE3s................................................................................................................................. 53
Troubleshooting.......................................................................................................... 55
General Troubleshooting ........................................................................................................................ 55
Troubleshooting Error Messages ........................................................................................................... 57
Troubleshooting Firmware Updates ....................................................................................................... 58
Specifications.............................................................................................................. 59
Regulatory Specifications ....................................................................................................................... 59
FCC Information to the User .......................................................................................................... 60
Firmware Revision .................................................................................................................................. 60
Temperature Range and Derating.......................................................................................................... 61
Default Settings and Ranges.................................................................................................................. 62

Table of Contents
900-0209-01-00 Rev A 5
Applications................................................................................................................. 65
Array Design ........................................................................................................................................... 65
Sizing Guidelines................................................................................................................................ 65
Maximum-Power Voltage (Vmp) .......................................................................................................... 65
Open Circuit Voltage (Voc) .................................................................................................................. 65
Temperature Conditions..................................................................................................................... 66
Maximum Power Point Tracking............................................................................................................. 66
Three-Stage Battery Charging................................................................................................................ 67
Bulk..................................................................................................................................................... 67
Absorption .......................................................................................................................................... 67
Float.................................................................................................................................................... 68
Equalize.............................................................................................................................................. 68
Battery Temperature Compensation .................................................................................................. 68
FLEXnet DC Battery Monitor (FN-DC) ................................................................................................... 69
Positive-Ground Applications ................................................................................................................. 70
Positive-Ground Networked Devices.................................................................................................. 70
Positive-Ground Non-Networked Devices.......................................................................................... 70
Grid-Interactive Settings ......................................................................................................................... 71
Definitions ............................................................................................................................................... 71
Index............................................................................................................................. 73
List of Tables
Table 1 Components Included................................................................................................................ 8
Table 2 LED Indicators ......................................................................................................................... 29
Table 3 Absorption Timer ..................................................................................................................... 32
Table 4 Reasons for Silent Mode ......................................................................................................... 34
Table 5 Battery Status LED Indicators ................................................................................................. 35
Table 6 AUX Mode Functions............................................................................................................... 45
Table 7 Troubleshooting....................................................................................................................... 55
Table 8 Error Messages ....................................................................................................................... 57
Table 9 Firmware Update Issues.......................................................................................................... 58
Table 10 Electrical and Mechanical Specifications ................................................................................ 59
Table 11 Environmental / Safety Specifications ..................................................................................... 59
Table 12 FLEXmax Settings................................................................................................................... 62
Table 13 Maximum Input Wattage Per Charge Controller ..................................................................... 65
Table 14 Examples of Compensation..................................................................................................... 69
Table 15 Terms and Definitions.............................................................................................................. 71

Table of Contents
6 900-0209-01-00 Rev A
IMPORTANT SAFETY INSTRUCTIONS
READ AND SAVE THESE INSTRUCTIONS!
This manual contains important safety instructions for the FLEXmax 100 charge controller.
Symbols Used
WARNING: Hazard to Human Life
This type of notation indicates that the hazard could be harmful to human life.
CAUTION: Hazard to Equipment
This type of notation indicates that the hazard may cause damage to the equipment.
IMPORTANT:
This type of notation indicates that the information provided is important to the installation,
operation and/or maintenance of the equipment. Failure to follow the recommendations in
such a notation could result in voiding the equipment warranty.
NOTE:
This type of notation indicates that the information provided is important to understanding the
operation and limits of the equipment. Failure to follow the recommendations in such a
notation could result in improper or failed operation.
MORE INFORMATION
When this symbol appears next to text, it means that more information is available in other manuals relating to the
subject. The most common reference is to the FLEXmax 100 Quick Start Guide. Another common reference is the
system display manual.
General Safety
WARNING: Limitations on Use
This equipment is NOT intended for use with life support equipment or other medical
equipment or devices.
WARNING: Reduced Protection
If this product is used in a manner not specified by FLEXmax 100 product literature, the
product’s internal safety protection may be impaired.
CAUTION: Equipment Damage
Only use components or accessories recommended or sold by OutBack Power Technologies
or its authorized agents.

900-0209-01-00 Rev A 7
Introduction
Thank you for purchasing a FLEXmax 100 Series Charge Controller. These charge controllers offer an
efficient, safe, multi-stage recharging process that prolongs battery life and assures peak performance
from a PV array of up to 300 open-circuit volts (V
oc
).
Audience
This manual provides instructions for installation, setup, and operation of the product. These instructions
are for use by qualified personnel who meet all local and governmental code requirements for licensing
and training for the installation of electrical power systems with AC and DC voltage up to 600 volts.
Failure to install or use this equipment as instructed in the literature can result in damage to the
equipment that may not be covered under the limited warranty. This product is only serviceable by
qualified personnel.
IMPORTANT:
This manual provides safety guidelines and installation information for the FLEXmax 100
charge controller. It does not provide information about specific brands of PV modules and it
supplies limited information on batteries. Contact the supplier of the PV modules or batteries
for additional information.
Features
The FLEXmax 100 charge controller uses continuous Maximum Power Point Tracking (MPPT). This
function continuously seeks out the maximum power available from a PV array and harvests it. This
power is used to recharge the batteries. See page 66 for a description of MPPT.
The FLEXmax 100 has the following features:
Designed for operation as part of an OutBack Grid/Hybrid™ system
Supports 24, 36, and 48 Vdc battery voltages
Wide input voltage range allows the use of a PV array configuration up to 300 V
oc
Controls an equalization cycle manually or automatically
Rain-proof enclosure
Logs up to 128 days of operational data
Field-upgradeable firmware
Can be remotely monitored and configured (up to 300 feet or 100 meters away) using MATE3s system display
~MATE3s must use firmware revision 001.002.000 or higher
~This product is not intended for use with the previous MATE, MATE2, or MATE3 products
Supports the OPTICS RE™ online tool
1
for a cloud-based remote monitoring and control application
~Requires the MATE3s or the AXS Port
~Visit www.outbackpower.com to download the software
Firmware
This manual covers FLEXmax 100 firmware revision 001.001.000 or higher.
1
Outback Power Technologies Intuitive Control System for Renewable Energy

Introduction
8 900-0209-01-00 Rev A
Components and Accessories
Table 1 Components Included
1 × FM 100 Charge Controller
2 × Mounting Bracket
1 × Silicone Grease Package
1 × Fan
Figure 1 Features & Wiring Cover
Battery Types
The default settings of the FLEXmax 100 charge controller are for lead-chemistry batteries intended for
deep discharge. These include all energy storage offered by OutBack Power as well as batteries for
marine, golf-cart, and forklift applications. They also include gel-cell batteries and absorbed glass-mat
(AGM) batteries. OutBack Power recommends the use of batteries designed specifically for renewable
energy applications. Lithium-based batteries and other advanced battery technologies may require
special charging considerations.
To remove the wiring compartment cover:
1. Using a Phillips screwdriver, remove the two screws from
the bottom of the compartment cover. (See above.)
2. Grasp the lower edge as shown. Swing the cover out
while pulling downward.
Equalize
switch
Status indicators
with universal symbols
Easily accessible
wiring
compartment
Rainproof
enclosure
Cover screws

900-0209-01-00 Rev A 9
Installation
Standards and Requirements
Installations must comply with all national and local electrical codes. Professional installation is
recommended. See page 7 for qualifications of installers.
A FLEXmax 100 charge controller operating in unventilated or in other conditions above an ambient
temperature of 25°C (77°F) will have a derated power output. See page 61 for more information.
If damaged or malfunctioning, the FLEXmax 100 should only be serviced by qualified personnel.
Please contact the local renewable energy dealer/installer for assistance.
Dimensions
Figure 2 FLEXmax 100 Dimensions
Wiring
compartment
height
4.4” (11.2 cm)
Side Plugs:
3.27” (8.3 cm)
De
p
th 6.0”
(
15.2 cm
)
Height
18.6”
(47.2cm)
Height
with fan
22.06”
(56 cm)
Bottom Plugs:
3.3”
(
8.4 cm
)
W
idth 8.8”
(
22.4 cm
)
Wiring compartment
opening width
6.9” (17.6 cm)
These openings are for 1” conduit
(1⅜” actual diameter)

Installation
10 900-0209-01-00 Rev A
Installation
Installing the Fan
The fan must be connected before the controller can be used, though it does not have to be installed first.
Figure 3 Installing the Fan
Mounting the Charge Controller
The FLEXmax 100 must be mounted upright on a wall or similar flat upright mounting surface. It must be
mounted at least 36” (91.4 cm) above the ground or floor. No other mounting positions are allowed.
Installation in shade is recommended.
Clearance requirements include a minimum of 6“ (15.2 cm) above and below the controller. On the right
and left sides, 1” (2.5 cm) clearance is sufficient. This includes clearance for multiple controllers installed
next to each other.
Two mounting methods are available. The first method uses keyhole slots on the back of the controller for
hanging directly on a wall. This method is useful for a standalone installation.
To install the cooling fan:
1. Place the fan against the base of the controller. Two of
the heat sink fins have holes which receive the locking
tabs on the fan. Align the tabs with these fins.
2. Press the fan straight along the fins until the tabs snap
into the holes.
3. Insert the fan connector through the hole in the
back of the controller and into the fan port in
the wiring compartment. (See illustration below;
also see page 19.)
Fan installation is complete. The fan will operate
automatically based on the internal temperature.
See page 38 to read the temperature using the
system display. This page also lists the
temperatures at which the fan turns on and off.
Heat
Sink
Fins
Tab

Installation
900-0209-01-00 Rev A 11
Keyhole Slot Mount
Figure 4 Mounting the Charge Controller (keyhole)
To mount using keyhole slots (A):
1. Use two slotted #14 wood screws. The mounting surface must
be strong enough to support the weight of the FLEXmax 100.
NOTE: OutBack is not responsible for damage resulting from
inadequate mounting hardware or preparation.
2. Mark the locations where the screws will be inserted on the
surface as in B. Space them according to the keyhole slot
locations as in D.
NOTE: The brackets included with the controller have holes
with the same spacing which can be used as a marking template.
3. Using the appropriate tools, set the screws into the
surface. The heads should protrude by ⅛” (0.3 cm).
4. Hang the FLEXmax 100 by placing its back against the
mounting surface and aligning the keyhole slots with
the screws. Settle the controller so that the screws
seat in the narrow end of each slot.
5. Secure the base of the controller to the surface. Insert
two ¼” hex head lag screws into the holes shown in C.
Keyhole slots
A
B
Securing holes
C
DSlot spacing 7.9” (20.1 cm)
Hole spacing 5.5” (13.9 cm)
Distance
16.9”
(42.9 cm)
Mounting is complete. Proceed to charge controller wiring or other installation steps.

Installation
12 900-0209-01-00 Rev A
Bracket Mount
The second mounting method uses brackets on the top and bottom of the controller. This method is
useful when mounting the controller next to an OutBack inverter system, as the conduit openings will
align. It is also useful for mounting without making advance measurements. The FLEXmax 100
controller comes with two identical brackets.
Figure 5 Mounting the Charge Controller (brackets)
To mount using brackets:
1. Using two ¼” hex head lag screws, mount the lower
bracket with the tabs facing upward. The mounting
surface must be strong enough to support the added
weight of the FLEXmax 100.
NOTE: OutBack is not responsible for damage
resulting from inadequate mounting preparation.
2. Lower the FLEXmax 100 onto the bracket as shown
to the left. The bracket tabs can be inserted in one
of two positions: forward or rear.
To mount the controller flush against the wall, insert the
tabs in the forward slots as shown below.
To mount the controller 0.83” (2.1 cm) from the wall to
align with an OutBack mounting plate, insert the tabs in
the rear slots as shown below.
NOTE: The charge controller can rest on the lower
bracket for the rest of the procedure, although it will
need at least one hand to steady it.
3. Insert the upper bracket into the same set of slots as
were used with the lower bracket (forward or rear) as
shown to the left.
4. Using two ¼” hex head lag screws, attach the upper
bracket to the mounting surface as shown to the left.
Mounting is complete. Proceed to charge controller
wiring or other installation steps.
4
Forward
slot
Rear
slot
Rear
slot
Forward
slot
Bracket hole spacing: 5.13” (13.0 mm)
Vertical space between upper and lower
bracket holes: About 20" when mounted

Installation
900-0209-01-00 Rev A 13
Wiring
This section provides instructions on installing PV array wiring into the charge controller. See page 65 for
more notes on PV array sizing. All wiring must comply with local and national codes.
Grounding
This product is intended to be installed as part of a permanently grounded electrical system. This
grounding is shown in the wiring diagrams in this book. Grounding methods must comply with local and
national codes.
The FLEXmax 100 equipment ground is marked with this symbol:
IMPORTANT:
 The FLEXmax 100 includes internal ground-fault protection and meets the requirements of
the 2017 National Electric Code, Article 690.41(A)(1) for two-wire PV arrays with one
functional grounded conductor.
 Bonding one of the battery conductors to ground is required for NEC compliance and is
strongly recommended in any case. The product comes with a functional bond
established from negative to ground. For positive-ground installation, see page 14.
 The battery conductor (positive or negative) must be bonded to the grounding system at
only one point. An external bond should not be present elsewhere in the system unless
the bond in the FLEXmax 100 is intentionally removed. If present, another bond will
defeat the GFDI protection. See page 15.
 If required, external ground-fault protection can be used with this product, such as the
OutBack GFDI or PV system grounding in compliance with NEC 690A)(5). See page 15.
CAUTION: Equipment Damage
 For positive-ground systems:
~The FLEXmax 100 internal GFDI function cannot be used in a positive-ground
system. It must be disabled before use. Any GFDI protection must be external.
~This product can be used in a positive-ground system when networked with one
OutBack inverter and a HUB communications manager. It cannot be networked in a
positive-ground system with multiple inverters. See page 14 for other requirements
in a positive-ground system.
~For use of the FLEXnet DC Battery Monitor or other devices in these applications,
see page 70.
 Failure to follow these instructions can damage the controller and other devices. This
damage is not covered under warranty.
Negative-Ground Systems
WARNING: Shock Hazard
Failure to bond one battery conductor to the grounding system can present a risk of
electric shock.
CAUTION: Equipment Damage
Failure to follow ground bonding instructions can damage the FLEXmax 100 and other
devices. This damage is not covered under warranty. Failure to follow these instructions may
also result in noncompliance with NEC or other codes.
The FLEXmax 100 uses a jumper wire to create a functional ground for one conductor. Connecting this
wire completes a mechanical connection (bond) between one battery conductor and the ground. The
default position creates a negative-to-ground bond, the most common configuration (item Ain Figure 6).

Installation
14 900-0209-01-00 Rev A
The negative jumper position also completes a connection to the internal ground fault detection and
interruption (GFDI) circuit. (See the GFDI section on page 15.)
NOTE:
When installing multiple controllers, remove the bonding jumper from all controllers but the
first one. Do not remove all bonds from the system.
Removing the bonding jumper wires from all controllers may result in an unbonded system
unless a bond is established elsewhere. Note that disconnecting the wires will also defeat the
internal GFDI function. Establishing a bond elsewhere will not allow the GFDI function to work.
Figure 6 Bonding Jumper
Positive-Ground Systems
The FLEXmax 100 has several critical requirements when used in a positive-ground system.
The internal GFDI function cannot be used. However, make certain to leave the GFDI fuse in place.
Ensure neither PV conductor is grounded. The battery conductor is the only item to be grounded.
Take these additional steps.
Remove the bonding jumper wire (item Ain Figure 6).
Establish an external positive-to-ground bond. The controller does not provide this bond.
Several other requirements must be met to maintain NEC compliance.
Install a dual-pole PV input circuit breaker to protect both the positive and negative conductors.
Install external GFDI protection. (See the GFDI section on page 15.)
Page 22 depicts a positive-ground system. See page 70 for requirements when networking other devices
on positive-grounded systems.
A
Battery –
Ground

Installation
900-0209-01-00 Rev A 15
Ground Fault Detection and Interruption (GFDI)
If a ground-fault event occurs, the controller’s GFDI fuse will open. The FLEXmax 100 GFDI circuit
detects continuity across the fuse. Lack of continuity will cause the charge controller to shut down. If the
fuse is not initially installed, the controller will be unable to operate. In either case the LED indicators and
the system display will show GFDI Fault. (See pages 30 and 38.)
If multiple controllers are used on a common system, all but one fuse must be removed. The other
controllers will detect the continuity of the remaining fuse. All units will then respond equally to a ground
fault. Figure 7 shows how the fuse is removed or replaced.
IMPORTANT:
 Removing the fuse from all controllers (or failing to install it) will prevent the controllers
from functioning.
 Using multiple fuses will keep the FLEXmax 100 GFDI protection from working as
specified. It will also establish multiple ground bonds, potentially leading to other error
conditions. This will result in noncompliance with NEC or other codes.
 Removing the ground bonding wire from all controllers will defeat the GFDI function.
This is a requirement in positive-ground systems. See the Ground Bonding section.
Figure 7 GFDI Fuse
External GFDI
IMPORTANT:
An external ground fault device must also contain the means for PV disconnection.
This function is built into OutBack GFDI products.
If alternate PV system grounding configurations or GFDI methods are required, remove the ground
bonding jumper wire from all FLEXmax 100 controllers. (See Figure 6 and the Ground Bonding
section.) Do not remove the GFDI fuses from any controllers. Once the bonding wire has been removed,
the external ground fault device can be installed according to its own instructions.
1. To remove the fuse holder A, simply
grip it tightly by the top handle and pull
upward. The fuse and holder will
unsnap from the board.
2. To open the fuse holder, push on the
two halves of the top handle in
opposite directions as shown in B.
The holder will open on a hinge.
3. The fuse Ccan be
easily removed and
replaced as needed.
Replace with a fuse of
the same type.
4. Replace the fuse holder by following these instructions in reverse.
A
B
Hinge
C
Hinge

Installation
16 900-0209-01-00 Rev A
Wiring Size and Requirements
CAUTION: Equipment Damage
Do not use a power driver or other power tools to tighten wire terminals. This can
damage them.
IMPORTANT:
Wire sizes must comply with all local and national codes. Input conductors and circuit
breakers must be rated at 1.56 times the short-circuit current of the PV array (per NEC).
OutBack 100% duty continuous circuit breakers only need to be rated at 1.25 times the
short-circuit current.
Please refer to the NEC and other electrical codes for PV array cable sizing, cable length, and cable ampacity.
Use #4 AWG (25 mm
2
) wire (minimum) for the output between the FLEXmax 100 and the battery bus bar
conductors. Smaller cables can reduce performance and possibly damage the unit.
The output can accept conductors up to #2 AWG (35 mm
2
). Larger conductors will reduce losses and ensure
highest performance of the FLEXmax 100. Use 90°C copper wire.
The maximum permitted conductor size for connection to the grounding wire terminal block is #6 AWG
(16 mm
2
). Use 90°C copper wire.
Install properly sized overcurrent protection devices. The minimum AIC (amps interrupting capacity) rating
required is 1125 Adc.

The largest PV array must have a rated short-circuit current of 64 amps or less under STC (Standard
Test Conditions). The output current limit of the FLEXmax 100 is 100 amps.
DC battery overcurrent protection must be used as part of the installation. OutBack offers both circuit breakers
and fuses for overcurrent protection.
Circuit Breaker Size and Requirements
The input (PV) and output protective devices must be sized according to the installation requirements.
OutBack offers a range of circuit breakers to meet these requirements.
Input Circuit Breakers
PNL-40-300VDC 40 amp single pole
PNL-40D-300VDC 40 amp double pole
PNL-60-300VDC 60 amp single pole
PNL-60D-300VDC 60 amp double pole
PNL-80-300VDC 80 amp single pole
PNL-80D-300VDC 80 amp double pole
Output Circuit Breakers
PNL-100-300VDC 100 amp single pole
PNL-125-300VDC 125 amp single pole
PNL-100-300VDC 100 amp single pole with plastic shield
PNL-125-300VDC 125 amp single pole with plastic shield
NOTE: The plastic shield provided with PNL-100-300VDC and PNL-125-300VDC provides important
insulation between devices. Install this shield before installing multiple adjacent circuit breakers. Do not
throw this shield away.

Installation
900-0209-01-00 Rev A 17
Physical Requirements and Conduit
IMPORTANT:
Conduit hubs must connect to the conduit before connecting to the FLEXmax 100.
WARNING: Burn Hazard
The heat sink can become hot when the charge controller is operating. Use caution when
touching it during operation.
All wire lugs and ground terminals are to be tightened to a torque value of 4 Nm (35 in-lb).
If installing in a wet location, any conduit hubs must comply with the requirements of UL 514B.
Run positive and negative cables side by side.
~Tie or twist cables together as much as possible to allow the inductive currents to cancel.
~Ensure paired cables pass through the same knockout and conduit fittings.
PV and Battery Terminals
WARNING: Shock Hazard
When a PV array is exposed to light, it immediately generates a voltage. Make sure all DC
circuit breakers are OFF (open) BEFORE making any wiring connections. Open both the
battery disconnect devices and the array disconnect devices to ensure isolation of the
controller. Use a DVM to check for voltage on all wires.
CAUTION: Equipment Damage
Each FLEXmax 100 requires its own PV array. DO NOT PARALLEL PV+ and PV-
TERMINALS OF MULTIPLE CONTROLLERS ON THE SAME ARRAY!
The negative (–) PV and negative (–) BAT terminals are connected internally. Only one wire is needed to
connect to the negative (–) wire lugs if the negative (–) PV and BAT conductors are connected at the
negative bus bar. See Figure 14 on page 22 for an example.
Figure 8 Wiring Compartment
See Figure 14 through Figure 16 beginning on page 22 for sample wiring diagrams.
PV+ PV– BAT– BAT+
DC
Terminals
Ground

Installation
18 900-0209-01-00 Rev A
Accessory Terminals and Ports
Figure 9 Wiring Compartment
Reset Button
This button is used for several functions, including updating the FLEXmax 100 firmware. See page 53.
HUB Port
This is an RJ-45 port for a CAT5-style cable to connect OutBack system displays or the HUB
communications manager.
Device and LAN Ports
These ports are not currently active. These ports can be activated in the future using firmware updates.
Remote Temperature Sensor Port
An optional battery Remote Temperature Sensor (RTS) is recommended for accurate battery charging.
When the system includes an OutBack MATE3s system display, a HUB Communications Manager,
and multiple devices, only one RTS is needed. The RTS should be connected to the port on the
FLEXmax 100. The system display gives this port the highest priority and will communicate
compensation values to all other devices.
Specialized temperature compensation is available. See page 43 for more information.
Fan Connector
Accessory Terminal
Block
Remote Temperature
Sensor (RTS) Port
MicroSD Card
HUB Port
Reset Button

Installation
900-0209-01-00 Rev A 19
SD Card
When enabled, the microSD card inserted in the slot will record operational status data about the system.
The FLEXmax 100 will record data to the microSD card up to the limit of the card. (It has been tested
with microSD cards up to 16 GB.) If the card’s capacity is exceeded, the data will begin to be overwritten
starting with the oldest first.
The microSD card can also be used to update the FLEXmax 100 firmware. See page 53.
Fan Connector
This is the connection for the FLEXmax 100 cooling fan. See page 10.
Accessory Terminal Block
This block of terminals has connections for the A UX output, for the Battery Sense function, and for the
Rapid Shutdown function. The terminals accept wire from #16 AWG to #24 AWG.
Press on the indented area Awith a narrow tool to unlock each opening while inserting the wire in B.
The wire should be inserted at approximately a 45° angle (perpendicular to the opening).
Figure 10 Accessory Terminal Block
Rapid Shutdown Terminals
Terminals 1, 2, 3, and 4are used for the Rapid Shutdown function. In an emergency, a responder may
need to quickly place the PV system in a de-energized state. These terminals can receive Rapid
Shutdown commands to quickly shut down the FLEXmax 100. Multiple controllers can be connected in
parallel on a single Rapid Shutdown circuit. See page 24 for more discussion of the Rapid Shutdown
function, including hookup diagrams.
If an OutBack system display is present, the Rapid Shutdown function will deliver a Fault Input Active
error message (see page 38).
AUX Terminals
The A UX (Auxiliary) output is a small power supply that provides a 12 Vdc output current to an isolated
load. The Aux output can respond to many criteria and control many functions. These include cooling
fans, vent fans, load diversion, fault alarms, and automatic generator control. The A
UX can only control
one function at a time. Examples of A
UX applications are shown in Figure 11 and Figure 12 on the next
page. See page 45 for a complete description of A
UX functions and programming.
A
B

Installation
20 900-0209-01-00 Rev A
A UX terminals 5and 6are the A UX output – and + terminals. These terminals are colored gray (–) and
orange (+) for easy reference. The terminals can supply up to 250 mA at 12 Vdc (3 W). This circuit
contains electronic overcurrent protection, which resets after being overloaded. No additional fuses are
required for A
UX terminals.
The A
UX indicator illuminates when the output becomes active. (See page 30 for a description of the LED
indicators and their functions.)
Examples of AUX wiring
Figure 11 AUX Vent Fan
Figure 12 AUX Diversion Control
In this example, the AUX output directly drives a 12-volt vent fan. The – and + wires on the fan are connected to AUX terminals
5and 6, the AUX– and AUX+ terminals.
In this example, the AUX drives a relay that diverts wind power. The relay’s coil is connected to AUX terminals 5and 6, the
AUX– and AUX+ terminals.When the AUX output closes the relay (based on battery voltage), the relay diverts excess power to
a water heating element.
Relay
Element
Turbine
NOTE: Relays and elements shown are examples only and
may vary depending on the installation.