amberroot REHUB MPPT 48 User manual
Ver 2.0 1 REhub MPPT 48 User Manual
Amberroot Systems Private Limited
# 251/252, 3rd Main Road, 3rd Cross, JP Nagar III Phase, Bangalore –560078
REHUB MPPT 48
SOLAR MPPT CHARGER FOR UPGRADING 36/48V INVERTERS
User Manual
Ver 2.0
Copyright 2020 Amberroot Systems Pvt. Ltd. All rights reserved
Ver 2.0 2 REhub MPPT 48 User Manual
Product Warranty
1. We warrant the original goods purchased for a period of 12 months after
purchase.
2. Please register your device with the following Serial Number at
www.amberroot.com for validating this Warranty certificate.
3. Warranty is invalid if the device is used other than as intended by the
manufacturer.
4. Within the warranty period we will repair or replace at our option all failures which
are caused by material or manufacturing faults.
5. Amberroot will not be responsible for any consequential damage.
6. A warranty repair does not extend the warranty period.
Exclusions of Warranty
No warranty claims will be accepted for damages resulting from handling, use or
treatment that are not explicitly mentioned in this manual. In particular, damages
arising from the following causes are excluded from the warranty
1. Voltage higher than 150V across PV or battery terminals.
2. Battery cables connected across PV input terminals.
3. Accidental presence of liquids in the equipment or oxidation due to condensation.
4. Damage resulting from falls or mechanical shocks.
5. Opening the unit/lid or modifications carried out without the explicit authorization
of Amberroot Systems.
6. Damage due to atmospheric surge voltage (lightning).
7. Damage due to inappropriate transportation or packaging.
[Scan for company address and contact details.]
Company Seal:
Amberroot Systems Private Limited
# 251/252, 3rd Main Road, 3rd Cross, JP Nagar III Phase, Bangalore –560078
Ver 2.0 3 REhub MPPT 48 User Manual
1Introduction
REhubs enable adding Solar PV to existing back up solutions without the expense of replacing
the UPS/Inverter and Batteries. REhub controls the charging of the batteries from from two
sources –the Grid (charging by the existing UPS/Inverter) and the installed Solar PV.
Adding Solar PV is the logical way to extend the back up hours and reducing the dependence
on Grid Power - but must be done the right way. REhub provides the right combination for adding
Solar PV. REhub intelligently controls the charging process in a way that keeps the batteries safe
and therefore extends their life. They allow the maximal use of Solar power. The unit is based
on a high efficiency MPPT (Maximum Power Point Tracking) charge controller that maximizes
the extraction of energy from the PV panel.
2General information
2.1 About this User Manual
This manual contains all the necessary information and procedures to install, configure, use and
troubleshoot REhub Solar MPPT chargers for use with Inverters. It does not contain information
about Photovoltaic modules (PV) or Batteries or Inverters of various brands that can be
connected. For information of those devices, please refer to the instructions of each specific
manufacturer.
2.2 Important safety information
This manual contains important safety instructions. Read carefully the safety and operation
instructions before using REhub. Take into consideration all the warnings mentioned both on the
equipment & in this manual. Please follow all the instructions regarding the operation and use.
This user manual is intended to serve as a guideline for the safe and efficient use of REhub. This
manual does not contain any information meant for persons other than the personnel qualified
for the installation of such a product.
The installation and commissioning of REhub must be entrusted to qualified personnel. The
installation and use must comply with the local safety instructions and standards in force.
2.3 Symbols used in this manual
This symbol is used to indicate safety instructions which, if not followed, could
result in serious personal injury or death to the operator or the user.
This symbol is used to indicate a risk of material damage and/or the
cancellation of the Warranty.
2.4 WARRANTY: PRESERVE THIS DOCUMENT FOR ANY WARRANTY
CLAIMS
The warranty for this equipment depends upon the strictly following the instructions in
this manual. This Manual Contains The Warranty Period And Terms In The Last Page.
PLEASE PRESERVE THIS DOCUMENT.
Ver 2.0 4 REhub MPPT 48 User Manual
2.4.1 Limitations of Liability
We disclaim all responsibility and liability for damage, costs or losses resulting from an
installation that does not comply with the instructions, a faulty operation or inadequate
maintenance. The use of REhub is in any case under the responsibility of the customer.
THIS EQUIPMENT IS NEITHER DESIGNED NOR GUARANTEED TO SUPPLY INSTALLATIONS
USED FOR VITAL MEDICAL CARE NOR ANY OTHER CRITICAL INSTALLATION ENTAILING
POTENTIAL RISKS OF DAMAGE TO PEOPLE OR TO THE ENVIRONMENT.
We assume no responsibility for the infringement of patent rights or other third parties rights
resulting from the use of the Charger.
Amberroot reserves the right to make any modifications to the product without prior notification.
AMBERROOT IS NOT LIABLE FOR INCIDENTAL, DIRECT OR INDIRECT DAMAGES OF ANY KIND,
INCLUDING ANY PROFIT LOSS, REVENUE LOSS OR DAMAGES CAUSED TO EQUIPMENT OR
GOODS DUE TO DEFECTIVE EQUIPMENT.
3Installation
3.1 UNPACKING
When unpacking, check that
the equipment has not been
damaged during
transportation and that all
accessories listed below are
present. Any fault must be
immediately reported to the
product distributor or the
contact mentioned at the end
of this manual.
Standard accessories:
Installation and operation
manual. One Battery Cable,
10/16 Sqmm, Black, 1 Meter
long.
3.2 Where to Install
REhub must be installed on a
flat wall vertically. Keep the
air vents clear of any
obstruction. Leave sufficient
space around the unit for air
circulation.
Install in an area which is
•Protected from any unauthorized person and children
•Protected from direct solar radiation or heat sources.
The presence of a heat source may significantly reduce its rated power. Similarly, insufficient
ventilation may lead to the overheating of some internal components of the equipment. In this
241
Ver 2.0 5 REhub MPPT 48 User Manual
case, the device will automatically limit its power as long as this abnormal situation persists. Do
not expose REhub to any dripping liquids.
Wiring must be done by a professional qualified for such installations.
Take extra care while connecting High voltage systems, Battery
terminals.
Take care to not connect the panels to the battery input or the
connection of the batteries to the PV input.
TAKE CARE not to connect the AC line to any of the DC (PV or Battery)
connections.
REhub is electronically protected against overloads, PV short-circuits, overheating, polarity
reversal of the battery, polarity reversal of the PV.
Access the cable compartment after removing the L Plate.
Cable entry is through the slot in the L Plate. Close the L Plate after the terminals are sufficiently
tightened and all the connections are checked for correctness.
3.3 Components of the Cable Compartment
S/no
Description
Comment
1
Terminal to connect Solar -Ve
Ensure appropriate cable size is used and
ends properly crimped to avoid accidental
shorts from stray strands.
Ensure that the input Voltage and Current
(String sizing) do not exceed name plate
ratings.
2,3
Terminals to connect Battery
+Ve and Solar +Ve. These are
close to each other because the
system uses Common +Ve
6
External Temperature Sensor
Connect the External temperature Sensor
(Part to be purchased from Amberroot) for
temperature compensation of Battery
charging (Optional)
4
Terminal to connect to
Inverter's Battery -Ve
Disconnect the connection between the
Inverter and Battery -Ve terminal, at the
Battery -Ve terminal, and connect to this
Image on the left is with
the L plate in place. On
the right is with the L
plate removed, exposing
the various terminals.
Ver 2.0 6 REhub MPPT 48 User Manual
terminal. This connection carries the full
current of the Loads from the batteries.
5
Terminal to connect Battery -
Ve
This connection carries the full current of the
Loads from the batteries and the charging
current from the Solar charger.
7
Barrier Terminal to connect AC
Live –Input from Mains
REhub controls the Mains input to the
existing Inverter with a heavy-duty relay.
This Mains input is internally connected to
this relay. Use a heavy-duty cable based on
the expected load.
8
Barrier Terminal to connect AC
Live –Output to Inverter
The Mains Output from REhub is from the
Output of the Relay –which switches off the
Mains input to the Inverter based on Solar
availability and the Battery state of charge.
Use a heavyduty cable based on the
expected load
9
Barrier Terminal to connect AC
Neutral Tap to measure AC
Voltage
This connection is a ‘Tap’ from the Neutral
terminal of the Mains OR the Inverter. This is
used by REhub to determine the availability
of AC from Mains. If connected as a ‘Tap’, the
wire cross section can be small because it is
not carrying the Load current.
10
RJ 45 Jack for access to RS485
Data
This port is in the RJ 45 form factor but is
not an Ethernet connection. Please use with
Amberlink adapters (available for purchase
separately) only.
3.4 Solar PV connections
REhub accepts input voltages between 0V to 150V. It can start charging the batteries when the
input voltage is above the battery voltage. Keep the connection ready. Close the connections
when you are ready to POWER Up.
3.4.1 Serial connection of Solar PV string
REhub can operate at a much higher PV voltage compared to the Battery system Voltage. It is
therefore not necessary to match the PV panel voltage to the Battery Voltage. However, the
name plate limits of the PV input must be strictly followed.
To get the optimum Voltage, the solar modules shall be connected in series to form a string
having the desired voltage. The optimum operating voltage of the module string (Vmpp) must
always be above the battery Voltage.
To establish the minimum number of PV modules to be connected in series in the same string,
the max voltage of the battery must be multiplied by 1.1 and divided by the modules Vmpp
voltage.
For example, for a 48V system with a lead-acid battery with maximum Voltage of 60V and using
PV panels with 17V Vmpp. 60*1.1/17=3.88.
The result must be rounded up to the higher value (i.e. 4 modules - of 17 Vmpp - in series for
the above example is the MINIMUM number of panels required for operation).
Maximum Panels in Series:
The open-circuit voltage of the string must be lower than 150V under any temperature and
irradiation conditions.
To establish the maximum numbers of the PV modules connected in series in the same string,
use the following formula: 135V/(Voc). (Example: 135/(22)=6.13). The result must be rounded
down to the lower value (i.e. 6 modules - of 22 Voc - in series for the above example).
There can be thus 6 PV modules in series of the mentioned model for as per this example.
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Table below gives an idea of the possible arrangements for common panels according to the
number of cells or their type.
Note that CIS or other forms of THIN film PV modules cannot be connected to REhub unless their
Voc is <135V.
3.4.2 Parallel connection of Solar PV string
To get the required charging power, 2 or more strings are usually to be connected in parallel.
Each string connected in parallel must be composed by the same number of modules of the
same type.
The number of strings connected in parallel depends on the Isc of each string. The Isc of the
array must be <40A for REhub MPPT, 40A Version. When you need to determine the Isc of the
parallel array, it is the Isc of each panel multiplied by the number of parallel strings. For
example, if the Isc of the panels used in the system is 4A. The maximum number of Parallel
strings → 40A/4A =10.
The total power of the array can be slightly higher than rated power of REhub. This excess
capacity is designed in to get the desired charging power under all circumstances of Solar
radiation. However, the output current from REhub will be limited to the maximum rated current.
(This is 40A in REhub 48-40A models)
3.5 Cable Size
Based on Array arrangement, calculate INPUT current. Choose the appropriate cable size for
INPUT current based on the length of the cable from the PV panels to REhub. REhub must be
located close to the Batteries.
3.6 Battery Connection
REhub monitors the net current delivered to the Batteries. REhub is by default configured to
allow a maximum of 18A net current into the batteries. NOTE THAT THE TOTAL OUTPUT TO THE
LOADS IS STILL AS PER THE RATED OUTPUT OF THE CHARGER (40A) . What this means is that
the sum of the negative currents (currents drawn by the loads) and the positive currents
(currents delivered by Solar PV and Inverter) will be not more than 18A. This is ideal for Battery
size of 150Ah –typical home back up Batteries. This value can be changed through Amberlink.
(separately available for purchase). There are two connections to the batteries from REhub.
Connections [3] and [5] deliver the Solar charge to the batteries. Connections [4] is to monitor
the battery currents. The existing Inverter Battery -Ve must be disconnected from the battery
and connected to REhub terminal [4]. Keep the Inverter in switched off / Away mode till you are
ready with all connections. Do not close the Battery connections till you are ready for POWER
UP.
Note: Do not use a washer between the Battery lugs and the terminal [4,5]. Allow direct contact
of the lugs to the terminals to reduce resistance.
Solar PV panels in a string
36 Cell Solar Panel with
Voc<23V
60 Cell Solar Panel with
Voc<38V
72 Cell Solar Panel with
Voc<45V
Battery
Voltage
Min
Max
Min
Max
Min
Max
36V
4
6
3
3
2
3
48V
4
6
3
3
2
3
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3.7 Inverter Connection
REhub is meant to add SAFE Solar PV to existing Inverters. The Mains input LIVE of the Inverter
is controlled by REhub. Disconnect the mains to Inverter connection and connect line cable to
REhub Line out socket.
The rated load current of the connected
inverter MUST be less than 100A. Keep the
inverter in away/off mode till you are ready
for the final power UP.
3.8 Mains Relay Operation
Control: Switching Between
Forced ON and Auto Control.
REhub by default is in Auto control of the
Mains Switch. REhub decides to switch off the
AC Mains input to the Inverter based on the
availability of Solar energy and the state of
charge of the batteries. This forces the
Inverter to use Solar energy to service the
Loads. Similarly REhub auto restores the
Mains connection when there is no Solar
energy or the state of charge of the batteries
is below a set value.
As a user you can decide to OVERRIDE the
decision of REhub by forcing REhub to keep
the Mains switch ON. In ONAlwas (For On
Always) mode, REhub keeps the Mains ON at
all times. In ON1Day (for ON One Day) mode,
REhub keeps REhub ON for the next 24 Hours
and goes back automatically to Auto Mode at
the end of 24 Hours. These Override modes
may be required in case the day is very
cloudy and Inverter is toggling frequently
between using Solar and using the Mains to
power the load. Alternately, these modes
may be required if heavy loads like Mixer-
grinder is connected to the lighting circuit
supported by the Inverter. When running a
Mixer, switch to ONAlwas or ON1Day mode
when power is available, to ensure the
Inverter is not delivering power from the
batteries to the Mixer. Make sure to switch
back to Auto when the desired usage is
completed.
Offgrid mode is a special mode in which the
MAINS power is not used unless the battery voltage goes very low. In Offgrid mode, REhub does
not switch on the Mains input to the Inverter even if Solar is not available. This mode is different
from the Auto mode in the way REhub switches on the Mains input to the Inverter. In Offgrid
mode it automatically switches on the Mains input only when the battery voltage reaches a set
low value.
Check to make sure LINE&
Neutral are NOT Swapped
Sometimes the LINE and Neutral is
swapped between the Input wire of the
Inverter and the Output Load socket. Even
with the swap prior to the installation of
REhub, the problem is not seen because
the Inverter delivers output from the
batteries only when the Mains are not
available. So a Line- Neutral swap from
input to output is not noticed
However when the Inverter's Mains input
is connected to REhub with the LINE –
Neutral interchanged between AC input
and output Load and when REhub forcibly
switches off the MAINS input to the
Inverter (even when MAINS power is
available in the daytime when Solar is
available), the Output Load may get
dangerously high voltage, because the
Inverter is delivering output from the
Batteries and the MAINS is also available.
Sometimes, the Neutral wire is connected
to the Live input of REhub. REhub operates
by switching off the Mains input to the
Inverter. This operation will not happen if
the Neutral is connected to the Live input
of REhub because the relay then is
switching ON or OFF the Neutral line and
not the LIVE!
Always make sure that the Input to Output
LIVE pins have continuity and that LIVE
and Neutral are not swapped in the
Inverter.
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4Powering Up
Connecting the battery terminals will energize and start the unit. Therefore connect the Battery
-Ve terminal at the battery terminal side last. Keep the -Ve Battery cable from REhub open till
the last when you are ready to power up. Before energizing the equipment, recheck the polarity
and the connections. Keep the MAINS MCB switched off.
A. Completing the PV+ and PV - connections.
Check the voltage between PV+ and PV- wires before closing the PV -Ve. You will get a voltage
approximately equal to the open circuit voltage of the array.
Note if the installation is being done in the night you will not get the Voc value but likely to get
a Voltage much lesser.
B. Connecting the battery: On the BAT+Ve and BAT-Ve terminals.
Remove the cable from the Battery -Ve terminal of the Inverter from the battery terminal and
connect to REhub.
Check the battery terminal voltage. Make sure you have chosen the right battery system voltage
for the REhub.
A 48V battery system will have voltage between 38V to 60V. On first time power on REhub will
go to Auto Detect Mode. By default this unit always charges to 48V battery system. DO NOT
CONNECT TO 36V battery system unless you confirm that the unit has been configured to work
with 36V battery system. This unit can be configured to work with 36V systems at the factory
ONLY.
C. Connecting the AC live from Mains connection.
Switch on the AC MCB. Put the Inverter to normal mode. Do this after REhub MPPT recognizes
the battery system voltage and starts functioning. IF YOU GET A BATT PROTECTION TRIP
ERROR –wait and the unit recovers and starts up again.
Take care not to swap Solar PV and Battery connections. The unit is not protected for such
a swap. The unit will not power up if batteries are connected in reverse polarity. If PV polarity is
swapped, the unit will show Solar as 'LOW'.
5Using Circuit Breakers for Safety
We recommend that a circuit breaker is installed in the following paths in the wiring. The circuit
breakers need to be purchased separately and is not supplied by default with the unit. Please
use appropriately rated DC MCBs only.
•A single pole DC MCB of minimum 40A,200V rating between the Solar +Ve
connection from the array and REhub.
•A single pole DC MCB of minimum 63A, 100V rating between the Battery +Ve
terminal of REhub and the battery.
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6Screens and indications
REhub has a 16X 2 LCD screen and three LED indicators. The display scrolls through various
screens and is a useful indicator for details on what is happening with the charger. The LED
indicators give a quick status update.
6.1 Information provided on the LCD screen
6.1.1 Start-up screens
Make sure that the correct battery system voltage is recognized. If the unit has been configured
for 36V system, the last screen above will show the battery system voltage as 36V.
6.1.2 Display screens
Solar LED
Off –No Solar
Blinking fast –Solar
good
Double blink –Solar
available but not being
used
Menu button
Press to scroll through
the different Menu
options
Select button
Press when you want
to select a Menu
option. The selection
may result in further
Menu options at a
level lower.
Mains LED
Off –No Mains
Blinking –Mains
available but not used.
(Mains input to
Inverter Off)
On –Mains available
and is being used.
(Mains input to
Inverter On)
Status LED
Blinking slow –All ok
Blinking fast –error
condition
REhub MPPT
Amberroot Sys
Model 141
36/48V –40A
Ver:0x035 DB:24
SL # 14100026
Battery System
Voltage 48V
Solar Y Mains Y
Mains to Inv: Y +
Battery
54.35V - 13.5 A
Solar Input
93 V
Solar Output
1250W 23 A
Int temp 36 deg C
Ext temp 28 deg C
Solar Units
12 kWhr
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The display scrolls through the screens shown above. Solar is Y if available. Mains is Y if
available. Mains to Inv is Y if the Mains input to the Inverter is ON. The + / - sign indicates that
a counter is running which will change the state from Y to N .
The Battery status screen shows the Net Amps delivered to the batteries and the battery
Voltage. By default, the maximum +Ve current to the batteries is set to 18A. A negative value
indicates that the Load is higher than Solar, and the Amps shown in being drawn from the
batteries.
The Solar output screen shows the Output Amps and the instantaneous Power generated.
The external temperature value is used for Temperature compensated battery charging. This
value is shown only of the external temperature sensor is connected to the unit.
The ‘Energy’ screen shows the Cumulative energy generated by Solar PV.
When the unit is set to a mode other than Auto, one of the following screens is additionally
shown in each cycle.
When the unit is set Auto –the following screen is shown at the time of transition only.
The different modes can be changed using the Menu and Select buttons. The Menu has the levels
as shown below. Selecting ‘Exit’ brings the screen back to scroll mode. Selecting ‘Back’ pushes
the screen to one level higher.
Mains Mode
OnAlwys
Mains Mode
On1Day
Mains Mode
Offgrid
Mains Mode
Auto
0 Exit
1 Mains Mode
2 Control
10 Back
11 Mains Auto
12 Mains 1 Day
13 Mains OnAlws
14 Offgrid
Mains Mode
Sel : In Auto
setting
Level 0
Level 1
Level 2
Mains Mode
Sel: On1day
setting
Mains Mode
Sel: OnAlws
setting
Mains Mode
Sel: Offgird
20 Back
21 Reset Solar
22 Reset unit
Solar Power output is based on the following factors
•Availability of Solar Power –depends on Solar irradiance.
•
Battery state of charge –When Batteries are in Bulk mode, the Solar charger limits the
Current to the batteries to a maximum of 18A. In Absorb or Float mode, the batteries
determine how much current is allowed.
•
State of Load. If the Batteries are full and Load is limited the Solar power has nowhere to go
and will therefore be limited. When loads go up, Solar power ramps up (Subject to
availability) and when Solar power alone cannot service the loads, battery is discharged to
service the loads along with Solar PV.
Ver 2.0 12 REhub MPPT 48 User Manual
Reset Solar forces the unit to do a complete scan of Solar and to start again. .
Reset unit forces the unit to completely reboot. The energy generated value is also reset to zero.
7Data Port
The data port streams the data seen on screen using MODUS PROTOCOL. It uses RS485 with RJ
45 jack. IT IS NOT AN ETHERNET port.
Please use with Amberlink adapter only. Contact us for details.
8REhub operation
REhub prioritizes keeping the batteries charged for sufficient back up. There are two
sources of energy to deliver power to the batteries. Solar PV panels and the Grid Mains
through the back up Inverter. REhub extracts power from the Solar Panel using a high
efficiency MPPT based charger. MPPT stands for Maximum Power Point Tracking and
the unit extracts power from the Solar panels at the voltage and current that delivers
the maximum power (called the Maximum Power Point). Since this Maximum Power
voltage and current varies, the Unit uses sophisticated algorithms to 'Track' this
maximum power point. Additionally, REhub allows the conversion of existing Inverters
to Solar based systems. REhub does this by controlling the Mains Input to the Inverter
and monitoring the net current delivered to the batteries. At all times, REhub ensures
that the batteries are kept safe and maximum Solar power is used to power the Loads.
REhub is designed to work with Inverters of any make (48V). However, it is advisable
to use REhub with efficient, Pure Sine Wave output Inverters.
Determine the approximate Loads (day time Load connected to the Inverters) and
match the number of Solar panels installed so that the energy generated per day is
approximately equal to the energy consumed by the loads for best results with your
Solar addition.
REhub functions in the following manner:
•When Batteries are discharged –the batteries are charged using both the Solar
PV and Grid if Mains power is available.
•When Solar is available AND Batteries are nearly completely charged (Voltage of
54V for at least 5 minutes), the GRID based charging from UPS Inverter is cut off
and Loads and Charging to the batteries are supplied from Solar PV.
•When Solar Power is unavailable OR the Battery Voltage drops to 49V and
remains in this state for at least 5 minutes, the Mains Input to the Inverter is
switched on again
•If the Battery is seen to be discharging too fast, the Mains Input to the Inverter
is switched on again
REhub ensures that the NET current delivered to the batteries at all times is 10% to
15% of the Battery Ah. The unit is by default configured to work with 150Ah batteries.
Note that when Loads are being serviced from Solar and Batteries, the Solar charger
could be supplying the current required by the Loads. Yet the net Current allowed into
the batteries will always be lesser than or equal to 15% of Battery Ah. The battery Ah
setting is a Factory setting. You can change this value through the data port by
purchasing a Data cable 'Amberlink' to access the data base of the system. The
configuration using Amberlink is given in a separate manual available with Amberlink.
Ver 2.0 13 REhub MPPT 48 User Manual
8.1 Battery charging stages
REhub follows a three-stage charging from the Solar PV.
•Bulk mode: As much current as available and permissible for the batteries is
delivered to the batteries
•Float mode: The batteries are charged. Only as much current as need to keep
the batteries charged completely is delivered.
•Absorb Mode: The unit keeps the battery Voltage constant till the Current
absorbed by the battery is lesser than 1A.
8.2 Connecting more than one array to a single battery bank
Sometimes it is desirable to connect a larger array to a single battery bank. For example the
loads may require an installation of 5kWp Solar array. Two REhubs, each connected to 2.5kWp
array (in this example) can be connected to the same battery bank. With REhub’s net current
monitoring feature, the output can be looped in a manner that the Loads get the desired say
80A current but the net current delivered by both the units is still restricted to the desired value.
(Say to 10% of the battery Ah). The wiring for this arrangement is shown in page 10 of this
manual.
9Error conditions
When an error occurs, REhub displays the error on the screen. Some errors are self-corrected
and once the error condition disappears, REhub resumes operation. Some errors may be system
errors that require correction in the system for recovery. In case you need support, please
capture an image of the error screen (and the next screen) for easier debugging.
Some possible errors are:
•Excess temperature
•Battery High voltage or Low Voltage error
•PV High voltage error
Bat Prot Trip: Sudden surge or voltage change is observed in the battery terminal. The next screen could
indicate the error # and the Battery Voltage. Please capture the details of this screen to help us zero in
on the problem faster.
High Temperature: Sustained Internal temperature beyond normal operating temperature. Could
indicate the Fan is nonfunctional.
Given below are some error conditions and what to do when you get them.
Error in System
Battery Prot Trip
Error in System
Err 12 61V
Error in System
High Temperature
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Error
Possible Reasons
Error Messages
Ways to eliminate
No Display
Batt Not On Or not connected
None
Turn on Battery
Battery Reverse
None
Check and connect
correctly
Battery Over Voltage
None
Check Battery Voltage
Zero Charging
Current
PV Not Connected
Solar V is Less than Bat
V
Connect PV
PV Reverse/Shorted
None / Solar Low.
Check and correct PV
Internal Error due to PV panel
Overcapacity
Error in System –Prot
Trip
Reduce PV Capacity /
Wait
Internal Error due to transients
arising due to long battery cables
Error in System –Prot
Trip / Batt Prot Trip.
Reduce battery Cable
length / Wait.
Internal Error due to transients
arising due to insufficient wire gauge
Error in System –Prot
Trip
Connect proper gauge
wire
Over temperature. (The unit cycles
through Charging and Tripping)
Error in System –High
Temperature
Wait for temperature to
reduce. Make sure there
is sufficient air
circulation. Also check if
PV panel connected is
more than what is
recommended.
PV Low/ Night time
Solar –Low
Wait for Sufficient
sunlight
Unit getting
stuck in
System Detect
Battery Voltage Very Low
None
Check the battery
health. Connect proper
12V or 24V Battery.
Not cutting off
Mains
Manual Override on
Mains Setting in ' Alwas
On' or 1DayOn
Change to Auto Mode
No Mains
Mains not connected
Mains –N
Check and connect
mains
Power Cut
Mains –N
Wait for Power to be
restored
In Auto Mode
Mains –N
Switch to Manual
Override Mode if Mains
Power is required
Battery Low
indication
In Off-grid mode
Inverter trips / indicates
Low Battery
Solar generation +
Battery back up is not
enough to tide over a
complete day
Ver 2.0 15 REhub MPPT 48 User Manual
10 Specifications
[1]
Operating principle
High efficiency MPPT Based Solar Charger to
enable addition of Solar PV to existing UPS
inverters. Monitors the net battery current to
ensure optimal charging rate and maximizes the
usage of Solar. RS485 based interface for
communication
[2]
Output Current Rating, Continuous, Max.
Temp Derate beyond 65 Deg Internal
40A
[3]
Battery System Voltage
48V
[4]
Recommended Solar module STC Wp
2500Wp
[5]
PV Open Circuit Voltage (VOC) Max
150V
[6]
PV MPPT Voltage range
Battery Voltage to 140V
[7]
Input Current PV (Max)
30A
[8]
Power Conversion Efficiency (typical)
95% typ
[9]
Full load output voltage
Same as battery voltage
[10]
Float Mode Charge Voltage
54 V (Configurable)
[11]
Bulk Mode Charge Voltage
58.6V (Configurable)
[12]
Ambient temperature range
-10°C to 55°C
[13]
Ports
1 pair of PV input separate positive and negative
1 +Ve Terminal output to be connected to
battery
1 -Ve terminal for current monitoring (-Ve)
1# of 3 Port barrier AC Terminal for Input and
Output AC Live and Neutral
1 RS485 Port
[14]
Dimension
307 X 182 X 107mm, IP20
[15]
Weight
~ 4 Kgs
[16]
Protections
[16a]
PV Reverse polarity
Electronically protected
[16b]
Battery Reverse
Electronically protected
[16c]
Over current protection
System shutdown, recovers with a timeout
[16d]
Over temperature protection
System shutdown, recovers with a timeout
[16e]
Battery Short Circuit
System shutdown, recovers with a timeout
[16f]
PV Short Circuit
System shutdown, recovers with a timeout
[17]
Indications
16X2 Character LCD. Displays, Battery V, Solar
instantaneous Power, Cumulative energy from
Solar
[18]
Relay
Dual contact, 20A AC Relay to control mains
input to Inverter
[19]
Notes : Communication
EXTERNAL: Modbus RTU 19.2kbps . Used to
communicate with PC / external device.
Ver 2.0 16 REhub MPPT 48 User Manual
Quick reference guide for the installation of REhub MPPT
Step 1
Prepare to connect
: Keep the cables ready. Draw the PV +Ve and -Ve wires to the battery
room. Make provision to mount the REhub on a wall close to the batteries and the Inverter.
Measure and cut a 10/6 Sqmm cable (RED) for connection between REhub and battery. Crimp
appropriate lugs to the cable ends. Remove the Inverter's battery -Ve cable from the battery -
Ve terminal
Step 2
Make the Solar connections
: Measure Open Circuit voltage, ensure it is within REhub
upper limit, make the PV -Ve connection to REhub. Connect the PV +Ve and battery +Ve cable
to the terminals on REhub.
Step 3A
Make the battery connections
: Measure the battery Voltage to make sure it is within
the operating limits of 48V battery system voltage. Connect the battery +Ve cable to the battery
terminal. Connect the Inverter's battery -Ve cable to REhub.
Step 3B
Complete the battery connections and REhub starts up
: Now connect the black
10/16Sqmm cable provided with REhub to the battery -Ve terminal of the batteries. This will
complete the battery connections and REhub will start up.
Step 4
Make the Inverter's AC connections
: Make sure there is no LIVE and Neutral Swap in the
Inverter's input and output. Connect the LIVE wire from Mains to Live-In terminal. Connect Live-
out terminal to Mains Live input of the Inverter. Connect a wire from the Neutral terminal of the
Inverter to the Neutral terminal in REhub. Close the L plate once the system working is verified
on the display screen. WAIT till you see REhub switching off the MAINS input to the Inverter and
the Inverter indicates that it is in back-up mode.
Installation mistakes
This section lists the installation mistakes that can occur. Installation mistakes can prove costly
and may have repercussions to the life of the product that is not immediately obvious.
S/no
Level
Mistake
Observation
Prevention, Correction
1
PV array voltage
> 150V
PV Protection trip
indication on screen.
If Voltage sustained
MoV can blow.
CHECK with Voltmeter before
connection.
If MoV blows, the unit needs to be
returned for repair. THIS IS NOT
COVERED under Warranty.
2
PV polarity swap
Solar is shown as N.
CHECK polarity with Voltmeter
before connection.
Reconnect with correct polarity
3
PV short circuit
PV Protection trip
indication on screen
Check connections.
Reconnect after resolving the
short.
4
Battery Reverse
Polarity
Unit does not power
up
CHECK with Voltmeter before
connection.
Reconnect with correct polarity
5
Battery Short
circuit
Track may open up
or weakest link will
burnup
Take extreme care in connections.
Use MCB to isolate for safety.
The unit may not be repairable.
6
Wrong battery
Voltage
Unit will freeze at
System Voltage
deduction.
CHECK battery Voltage with
Voltmeter before connection.
Ver 2.0 17 REhub MPPT 48 User Manual
Make sure the battery Voltage is
between 30 to 45V for 36V
systems and between 40 to 60V
for 48V systems.
7
Connecting 36V
battery system
to unit
configured for
48V
Unit may start up
but will be operating
at 48V set points.
Extremely
dangerous for the
Batteries.
Check name plate and make sure
you are using the correct version.
8
Battery –PV
Swap
Will blow the MoVs
in the unit.
The terminals for Battery and PV
in the unit are deliberately
designed differently. Be careful to
not mix the Battery negative and
PV negative.
If MoV blows, the unit needs to be
returned for repair. THIS IS NOT
COVERED under Warranty.
9
Connecting Live
-In to Live-Out
and Vice versa
The Relay operation
may be affected
Crimp Live-In first and complete
the connection before taking up
Live –Out connection.
10
Stray strands of
AC live -In or
Live-Out
touching the
enclosure
Can cause a
electrical shock
Use proper cylindrical lugs and
crimp tightly
11
Live –Neutral
swap
May cause Inverter
to trip or go bad.
Relay operation does
not happen correctly
REhub MPPT 48 uses only the Live
line to control the relay operation.
Make sure the wires are not
swapped.
12
Insufficiently
tightened
terminal screws
Heating up of the
terminals –
resulting in even the
terminal solder
giving up
Tighten the screws with enough
torque
If terminal Solder has melted, the
unit needs to be returned for
repair.
13
Under sizing of
wires
Wires get heated up.
Excessive Voltage
drop
Size wires based on acceptable
Voltage drop, Length etc.
Ver 2.0 18 REhub MPPT 48 User Manual
Check list for the installation of REhub MPPT
Sl
no
Description
Desired
Valve
Measured
value
Verified
1
Check PV Voc Voltage using multimeter
Less than
150V
2
Check Battery Voltage using multimeter
48V
System
(43.3 to
58V)
3
Check the polarity of the PV wires. Connect PV -
Ve Wire to PV port and check for tightness.
4
Connect Battery and Solar positive to common
+Ve terminal on REhub. Check for tightness.
5
Connect phase of power supply into Line In of
REhub. Check for tightness
6
Connect inverter Line Input to Line Out of REhub.
Check for tightness.
7
Connect Neutral of Power supply/ Inverter to
REhub’s Neutral terminal.
8
Connect Inverter/UPS to Battery negative to
appropriate terminal in REhub. Check for tightness
9
Connect Battery negative cable from REhub to
Negative terminal of the battery. Check for
tightness
10
REhub starts up and does System detect. Verify if
correct battery Voltage is detected.
Correct
battery
system
Voltage
11
Make sure that LINE and Neutral wiring in existing
Inverter matches the Mains / house wiring.
Connect the Inverter to REhub as described, Wait
and confirm that REhub switches off the Mains
input to the Inverter
Ver 2.0 19 REhub MPPT 48 User Manual
REhub MPPT 48V #1
REhub MPPT 48V #2
Solar -Ve from Array 1
Solar +Ve from Array 1
To Battery +Ve from REhub #1
From Inverter’s Battery -Ve
To Inverter’s Batt -Ve terminal in REhub #2
To Batt -Ve from REhub #2
Solar -Ve from Array 2
Solar +Ve from Array 2
To Battery +Ve from REhub #2
Din Rail
UK 10 Terminal
DC MCB 63A, 200V
DC MCB 63A, 200V
UK 10 Terminal
DC MCB 63A, 200V
DC MCB 63A, 200V
UK 35 Terminal
UK 35 Terminal
UK 35 Terminal
16Sqmm Cu Cable
16Sqmm Cu Cable
16Sqmm Cu Cable
16Sqmm Cu Cable
10Sqmm Cu Cable 10Sqmm
Cu Cable
6Sqmm Cu Cable
6Sqmm Cu Cable
6Sqmm Cu Cable
6Sqmm Cu Cable
Wiring two REhubs (two PV arrays) to a single
Battery bank and Inverter.
*Wire sizes are indicative. Size wires based in acceptable line loss and distance
from battery.
* External terminals are optional. MCBs are recommended for safety during
installation
Ver 2.0 20 REhub MPPT 48 User Manual
Port # Description
1 PV -Ve
2,3 Common
Batt +Ve, PV +Ve
4 Inverter's Batt -Ve
5 REhub Batt -Ve
Port # Description
6Ext Temperature Sensor
7
8 AC Live Output
9 AC Neutral
10 Data Port
AC Live Input
+Ve -Ve
Batteries 48V`
L N E
L N E
AC MAINS
Inverter
AC IN Battery Terminals
REhub MPPT 48
Solar PV
Connect max three 60/72
cell panels in series.
Connect more strings in
parallel as required.
1
2 3 4 5
6
7 8 9
10
40A DC MCB
(Recommended, not
supplied by
Amberroot)
63A DC MCB
(Recommended, not
supplied by
Amberroot)
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