MLT Inverters Nomad 80 User manual

+
NOMAD 80
User Manual

© 2017 MLT Inverters
3rd Edition – May 2017
NOMAD USER MANUAL PAGE 1

Table of Contents
1. Introduction .......................................................................................................................... 6
1.1 Warnings and Cautions................................................................................................ 6
1.2 Contacting MLT Inverters ............................................................................................ 7
1.2.1 Product Support................................................................................................... 7
1.2.2 Contact Details..................................................................................................... 7
1.2.3 Telephone ............................................................................................................ 7
1.3 System Specifications................................................................................................... 8
1.3.1System Ratings..................................................................................................... 8
1.3.2 Battery Input ........................................................................................................ 8
1.3.3 Efficiency .............................................................................................................. 8
1.3.4 General Specifications ......................................................................................... 8
1.3.5 Climatic Conditions.............................................................................................. 9
1.3.6 Operator Panel .................................................................................................... 9
1.3.7 Altitude Derating .................................................................................................9
2. Advanced Features.............................................................................................................11
2.1 Two Independent Maximum Power Point Trackers ................................................11
2.2 Wide PV String Voltage Range...................................................................................11
2.3 Ground-Fault Detector Interrupter ........................................................................... 11
2.4 Compatible with Various Battery Technologies .......................................................11
2.5 Lead-Acid Battery Equalise ........................................................................................11
2.6 Auxiliary Relay control ...............................................................................................12
2.7 MLT Bridge Communications (Optional Add-on) .....................................................12
3. Solar Calculations................................................................................................................13
3.1 Open Circuit Input Calculations .................................................................................13
4. Mounting and Electrical Connections ...............................................................................14
4.1 Installing the Nomad charge controller .................................................................... 14
4.1.1 Selecting a suitable location.............................................................................. 14
4.1.2 Mounting ...........................................................................................................14
PAGE 2NOMAD USER MANUAL

4.1.3 Making the electrical connections.................................................................... 15
5. Charge Controller Operation Indicators............................................................................17
5.1 Solar Status .................................................................................................................17
5.2 Charge controller Status ............................................................................................ 17
5.3 Battery Status ............................................................................................................. 17
6. Interface ..............................................................................................................................18
6.1 System Icons...............................................................................................................18
6.2 Dashboard .................................................................................................................. 18
6.3 Control Panel..............................................................................................................19
6.4 Graphing and Logs...................................................................................................... 20
6.4.1 Solar Output Graphs..........................................................................................20
6.4.2 Solar Sweep Graph ............................................................................................ 20
6.4.3 Battery Graphs................................................................................................... 21
6.4.4 Event logs ........................................................................................................... 21
6.5 Settings ....................................................................................................................... 23
6.5.1 Settings Menu.................................................................................................... 23
6.5.2 Setup Alarms...................................................................................................... 23
6.5.3 Date & Time .......................................................................................................24
6.5.4 Relay Control...................................................................................................... 25
6.5.5 MPPT Settings .................................................................................................... 26
6.5.6 Battery Setup ..................................................................................................... 27
7. Faults and Warnings...........................................................................................................30
7.1 Fault/Warning screen ................................................................................................ 30
7.2 Description of Warning and Faults............................................................................30
7.2.1 Operating Temperature Limit Reached............................................................30
7.2.2 High Battery Voltage.......................................................................................... 30
7.2.3 High Solar Voltage .............................................................................................31
7.2.4Incorrect Nominal Voltage ................................................................................ 31
8. Ground Fault Detector Interrupter (GFDI)........................................................................32
NOMAD USER MANUAL PAGE 3

8.1 Selecting ground fault reference............................................................................... 32
8.1.1 Battery Positive..................................................................................................32
8.1.2 Photovoltaic/Battery Negative ......................................................................... 32
8.1.3 Photovoltaic Positive ......................................................................................... 33
8.1.4 PV Floating .........................................................................................................33
9. External Connections .........................................................................................................34
10. Batteries ..............................................................................................................................35
10.1 General ....................................................................................................................... 35
10.1.1 Sealed Lead-Acid Batteries...................................................................... 35
10.1.2 Deep Cycle Lead-Acid Batteries ..............................................................35
10.1.3 Lithium Batteries...................................................................................... 35
10.2 Battery Bank Location................................................................................................35
10.3 Maintenance .............................................................................................................. 35
10.4 Replacing a Battery ....................................................................................................36
10.5 Lead-Acid Battery Charging .......................................................................................36
10.5.1 Charging Stages........................................................................................ 36
10.5.2 Battery charger settings .......................................................................... 37
10.6 Lithium Battery Charging ...........................................................................................38
10.6.1 Battery charger settings .......................................................................... 39
11. Trouble Shooting ................................................................................................................ 40
11.1 Faults...........................................................................................................................40
11.2 Typical Problems ........................................................................................................40
11.2.1 The Nomad is not charging the batteries...............................................40
11.2.2 Why didn’t I get the usual capacity from my storage batteries? .......... 40
12. Glossary ...............................................................................................................................41
Appendix A: Sample Single Line Wiring Diagram .......................................................................42
PAGE 4NOMAD USER MANUAL

Figures
Figure 1: De-rating the Nomad charge controller output power at high altitude ....................... 9
Figure 2: Identifying parts of the Nomad .....................................................................................10
Figure 3: Wall mounting................................................................................................................ 15
Figure 4: Input/output connections on the Nomad ....................................................................16
Figure 5: GFDI Jumper Selection (Bottom Cover Removed) .......................................................33
NOMAD USER MANUAL PAGE 5

1. Introduction
1.1 Warnings and Cautions
A safety instruction (message) includes a hazard alert symbol and a signal word, WARNING or
CAUTION. Each signal word has the following meaning:
HIGH VOLTAGE: This symbol indicates the presence of a high voltage. It calls your
attention to items or operations that could be dangerous to yourself or others
operating this equipment. Read the message and follow the instructions carefully.
WARNING: Indicates a potentially hazardous situation which, if not avoided, can result
in serious injury or death.
CAUTION: Indicates a potentially hazardous situation which, if not avoided, can result
in minor to moderate injury, or serious damage to the product. The situation
described in the CAUTION may, if not avoided, lead to serious results.
GENERAL WARNINGS
DANGER OF ELECTRIC SHOCK. There are no user serviceable parts inside the charge controller. DO NOT attempt
to make repairs or alterations to the unit.
WARNING: This equipment should be installed, adjusted, and serviced by qualified electrical maintenance
personnel familiar with the construction and operation of the equipment and the hazards involved. Failure to
observe this precaution could result in personal injury.
GENERAL CAUTIONS
CAUTION: Always wear personal protective equipment (protective clothing, gloves, and safety boots) while
performing an installation or maintenance, to avoid the danger of injuries.
CAUTION: Proper grounds, disconnecting devices, e.g. bypass boxes and other safety devices and their location
are the responsibility of the user and are not provided by MLT Inverters.
CAUTION: Do not cover the device or store it in a small space - always keep it well ventilated and well away from
flammable gases or powders. Components in the device could potentially cause a small electric spark that could
ignite flammable gas or powders. Flammable gases are created by batteries and can become a hazard in poorly
ventilated spaces.
CAUTION: For indoor use only and MUST be installed in a dry area free from conductive liquids or conductive
debris. If part of the charge controller becomes submerged in water look for a safe way to isolate it at the
distribution board and if possible at the batteries.
PAGE 6NOMAD USER MANUAL

1.2 Contacting MLT Inverters
1.2.1 Product Support
When contacting Product Support via telephone, email or fax please provide the following information
for the fastest possible service:
Charge controller model number
Serial number
Battery type
Battery bank capacity
Battery bank voltage
A description of the event
Note that the serial number is available on the serial plate that is attached to the bottom of the machine
inside the cover.
1.2.2 Contact Details
Telephone: [phone]
Email: [e-mail]
Address: 103 Garfield Road
Kenilworth 7708
Cape Town
South Africa
1.2.3 Telephone
You can reach technical support by telephone directly Monday to Friday between 08h00 and 17h00
(GMT +2 hours). Queries outside of these hours should be directed to [e-mail] and
will be answered at the earliest opportunity. When contacting technical support, please ensure that
you have the information listed above available.
NOMAD USER MANUAL PAGE 7

1.3 System Specifications
1.3.1 System Ratings
Nomad 80 Charge Controller
Number of Input Ports 2 (Individual MPPT Control)
Input Vmp Voltage Range 65 - 375 Vdc per port
Maximum Input Voltage 400 Vdc
Nominal Photovoltaic Power (24/36/48V) 1000 W / 1500 W / 2000 W (per port)
Maximum Photovoltaic Power (24/36/48V) 1500 W / 2250 W / 3000 W (per port)
Output Voltage range 20 – 63 Vdc
Max Battery Output Current 80A (2x 40 A per port)
Programmable Aux. Control Output 30Vdc / 277Vac / 5A relay
Protection Ground-Fault Detector Interrupter (GFDI), Overvoltage
(Photovoltaic and Battery), Reverse Polarity
(Photovoltaic and Battery)
1.3.2 Battery Input
Nominal Battery Voltages 24, 36 and 48 Vdc (configurable at start-up)
Battery Temperature Compensation Optional Remote Temperature Sensor (RTS) available
1.3.3 Efficiency
Efficiency Up to 95 % @ 80Adc in a 48Vdc system (typical)
No Load Power Consumption Less than 2.5 W
1.3.4 General Specifications
Mounting Method Wall Mounted (Bracket and fasteners included)
Dimensions (W x H x D) 210 x 380 x 147 mm (Shipping: 275 x 440 x 215)
IP/NEMA Rating IP20 / NEMA1
Colour RAL9002 / RAL9011
Weight 6 kg / Shipping: 6.2 kg
PAGE 8NOMAD USER MANUAL

Architecture Forced Air Cooling
Compliance IEC62109-1
1.3.5 Climatic Conditions
Ambient Temperature -10 to 60 °C (derated above 40°C)
Ambient Transport Temperature
-25 .. 70 °C
Maximum Ambient for Rated Power 40 °C
Relative Humidity (Non-Condensing) 5 .. 85 %
Maximum Altitude for Rated Power
1000 m above sea level
(Power derated for High Altitude)
1.3.6 Operator Panel
Display Type Full colour Touch screen 4.3 inch LCD
Graphs 24 hour history display of solar power production (both
ports), battery and most recent sweep graph (both
ports)
Data and Event Logs Daily solar production (kWh) and peak power (kW).
Logging of system events.
All specifications listed above performed at nominal voltage, frequency and temperature unless
otherwise noted.
1.3.7 Altitude Derating
Figure 1: De-rating the Nomad charge controller output power at high altitude
75
85
95
105
0 1000 2000 3000 4000
Percentage of Rated
Power
Altitude in meters above Sealevel
Altitude Derating
NOMAD USER MANUAL PAGE 9

Figure 2: Identifying parts of the Nomad
PAGE 10 NOMAD USER MANUAL

2. Advanced Features
2.1 Two Independent Maximum Power Point Trackers
The Nomad contains two fully independent MPPTs, perfect for residential
applications where PV arrays often face in a variety of directions. Connecting
such PV strings to separate MPPTs can increase energy yields significantly
compared to combining all strings into one MPPT.
2.2 Wide PV String Voltage Range
Each of the two MPPTs can accept PV string DC voltages between 65 and 350V. This wide range means
a single PV string per MPPT is possible, instead of being forced to parallel PV strings. This allows for
thinner DC cables, no string junction boxes and easier & lower cost installations.
2.3 Ground-Fault Detector Interrupter
A ground fault is the undesirable condition of current flowing through the grounding conductor. The
cause of this undesirable current flow is an unintentional electrical connection between a current-
carrying conductor in the PV system and the equipment grounding conductor.
This can create a number of hazards since the normally grounded current-carrying conductor may no
longer be at ground potential. The Nomad physically disconnects the PV-panels to ensure site and
operator safety.
The Nomad can be configured to detect ground faults on both positively and negatively grounded
photovoltaic arrays as well as negatively grounded battery banks.
2.4 Compatible with Various Battery Technologies
Unlike many MPPTs, the Nomad is compatible with a variety of battery technologies. For example, in
the event of a Li-ion battery trip, the Nomad will immediately disconnect, thereby protecting against
rapid battery DC bus rises which typically destroy slower MPPTs and connected inverters. The Nomad’s
charging voltage and current are fully adjustable, and it can communicate via CAN bus (optional).
2.5 Lead-Acid Battery Equalise
The Nomad charge controller has an equalise charge option available. This is
used on flooded lead-acid batteries to prevent battery sulfation by dissolving
sulphur crystals. An equalising charge also reverses acid stratification, a
condition where acid concentration is greater at the bottom of the battery
than at the top. Lastly, it also helps with cell balancing.
NOMAD USER MANUAL PAGE 11

2.6 Auxiliary Relay control
A single, no voltage dry-contact auxiliary relay can be controlled with the user
settings menu. This relay can be used to control external load relays, or any
other simple binary logical circuit you can think of.
2.7 MLT Bridge Communications (Optional Add-on)
The Bridge external optional add-on enables browser-based internet monitoring and control of the
Nomad charge controller. The Bridge must be connected to an internet network.
Visit our website for further details.
PAGE 12 NOMAD USER MANUAL

3. Solar Calculations
3.1 Open Circuit Input Calculations
The Nomad PV input ports has an operating range of 65-350Vdc.
When choosing the number of panels in series to connect to each Nomad port, consult the PV panel
specifications sheet and use the following formula:
Maximum panels per string ≤375 / (
 + (  × ( −25) x  / 100))
With:

 – Open circuit voltage at STC
 – Coldest ambient temperature the PV panels will ever be exposed to

– Temperature coefficient of   in % °
⁄
Warning: PV input voltages above 400Vdc will cause system damage and void the
product warranty.
NOMAD USER MANUAL PAGE 13

4. Mounting and Electrical Connections
4.1 Installing the Nomad charge controller
For optimal performance, please refer to the following instructions regarding the installation and setup
of your newly purchased Nomad.
4.1.1 Selecting a suitable location
When selecting a location to mount your charge controller, take note of the following:
1. The Nomad charge controller should be mounted indoors, in a well-ventilated area out
of direct sunlight, where the ambient temperature does not exceed 45°C (derating
applies).
2. The Nomad is designed to be wall-mounted, and must therefore be installed upright in
a vertical position, with a clearance of 200mm above and below, to allow sufficient
cooling and airflow. The wall must be able to take the full weight, otherwise use a
mounting frame.
3. The battery leads should be as short as possible, so that the Nomad charge controller
will need to be in close proximity to the batteries. (Standard cables length of cable are
available as optional accessories).
Note: At high altitudes natural thermal convection (natural thermal cooling) of the all electrical
equipment is degraded. This is due a lower air density available to remove heat from the heatsink. The
Nomad is rated for altitudes up to 1000m above sea level. If it is going to be installed in an area where
the altitude is greater than 1000m above sea level, refer to the power derating graph (Figure 1) to
establish the maximum continuous load.
4.1.2 Mounting
Once a suitable location for the Nomad has been chosen, use the following information as a guide to
make the mounting process easier using an M5x35 wall anchor:
1. Using an appropriate bit masonry drill bit (typically 7mm), drill 2 holes 45mm deep and
135mm apart. It is recommended to use the bracket as a template.
2. Insert the wall anchor bolts through the bracket into the holes, and tighten with a
screwdriver, fixing the bracket to the wall.
3. Hold the Nomad vertically and lift it onto the mounting bracket.
PAGE 14 NOMAD USER MANUAL

Figure 3: Wall mounting
4.1.3 Making the electrical connections
Once your Nomad has been mounted on the wall, you can begin making the electrical connections.
Follow these steps to make the task as simple as possible.
Caution: Failure to follow these instructions carefully could increase the risk of
personal injury, death or damage to property or equipment.
Ensure that any electrical connections is dead before touching any potential live
wiring. Certain electrical connections must be appropriately trained person. If in doubt
about anything, contact MLT Inverters for assistance.
1. Remove the screws that secure the removable bottom cover.
2. The ‘Earth’ terminal inside the Nomad must be grounded to reduce the risk of electrical
shock and to ensure that external earth-leakage protection device can operate correctly.
3. The ‘PV’ connections inside the Nomad will need to be connected into your solar array.
These connections should be made with an appropriately rated solar wire. Take care to
NOMAD USER MANUAL PAGE 15

connect the Positive wire to the ‘+’ terminal and the Negative wire to the ‘-’ terminal.
Ensure that the cables are rated appropriately for the environment and current.
4. Insert and tighten the battery cables to the DC battery terminal connections, taking care
to observe the polarity. Make sure to use cables rated to carry the full current output of
the Nomad.
5. Once all the electrical connections have been made, double-check that they are secure,
as a loose connection could get hot enough to cause a fire.
Note: External protection devices such as fuses, DC-circuit breakers and earth-leakage protection are
the responsibility of the owner, and not of MLT Inverters. MLT Inverters cannot be held responsible for
personal injury, death or damage to property or equipment caused by the improper use or installation
of this equipment. It is therefore recommended that all the electrical connections must be made by a
qualified electrician or an MLT Inverters approved installer.
Figure 4: Input/output connections on the Nomad
The above picture illustrates the location of the Battery Connection (red, remember to observe
polarity), Earth (green), the External Connections plug (blue), and the Solar (yellow).
PAGE 16 NOMAD USER MANUAL

5. Charge Controller Operation Indicators
On the front panel of the Nomad charge controller there is three LED status indicators:
Solar status Charge Controller
status Battery status
5.1 Solar Status
Green – The Nomad charge controller is active and there is sufficient power in order to charge the
batteries.
Orange – The charge controller is in sleep state. Either there is no solar irradiation or the battery is full.
Red – A solar fault exists, typically an overvoltage condition. Consult the screen for more information.
5.2 Charge controller Status
Green – The Nomad is operation is normal with no faults.
Orange – The charge controller is throttling the solar power output due to temperature.
Red – A fault condition exists. Consult the screen for more information.
Off – Charge controller is turned off.
5.3 Battery Status
Green – The battery is fully charged.
Orange – The battery state of charge is low.
Red – The battery state of charge has reached a critically low level.
Blinking Orange – The Nomad is performing an equalise charge.
NOMAD USER MANUAL PAGE 17

6. Interface
The Nomad HMI (Human Machine Interface) is a full colour 4.5” touchscreen interface. This chapter
covers using the interface to set up the Nomad charge controller.
6.1 System Icons
There are four system icons on the right hand column. Pushing on the icon select the current screen.
Dashboard Control Panel Graphing Settings
6.2 Dashboard
The Dashboard screen shows an overview of the current charge controller operation. Power coming
from the each of the solar arrays, and battery charging current. Clicking on each of the icons takes you
to the individual graphing screens.
From the top left, the source power draw and frequency is indicated underneath the red Source icon.
The red and dark blue Solar Panel icon indicated the current panel voltage and the amount of power
flowing from the panels.
The light blue Nomad icon indicates the mode that the charge controller is in.
PAGE 18 NOMAD USER MANUAL

The green Battery icon shows the battery voltage and the current that is charging the battery. The bars
within the icon are an indication of the state charge of the battery bank, with four bars implying a full
charge and one bar implying battery critical.
The directional arrow indicates which direction the power is flowing. The arrows from the solar arrays
indicate that power is flowing into the charge controller. The arrow pointing towards the battery,
indicates that the battery is getting charged.
The bottom part of the screen contains a bar, showing system status and indicates any known issues.
Next to it is the current date and time.
6.3 Control Panel
There are four button here with the followings functions:
Reset will clear any active event messages and turn the charge controller on. If the event message is
still present, it will not turn on.
Sweep forces the charge controller to recalculate the maximum power point for both the solar arrays.
Equalise turns on and off the equalise charge. If the equalise charge is selected, the next bulk charge
will be done at the equalise voltage.
On will turn on the charge controller. When on, the icon will change to Off, which will turn off the
charge controller.
NOMAD USER MANUAL PAGE 19