1
Introduction
REhub enables adding Solar PV to existing back up solutions that use 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.
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.
2
REhub MPPT Eco Operation
2.1
REhub 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. At all times, REhub ensures that the batteries are kept absolutely safe and maximum
Solar power is used to power the Loads. REhub is designed to work with Inverters (12V or 24V) of
any make. 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
amount 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 Batteries are >90% charged (Voltage >13.5/27V for at least 5 minutes) AND Solar PV
is available, the GRID based charging from UPS Inverter is cut off, Energy for the Loads and
Charging the batteries is supplied from Solar PV.
–
When the Battery Voltage drops below 12.3/24.6V and remains in this state for at least 5
minutes OR Solar PV is unavailable, the Mains Input to the Inverter is switched on again.
The set points can be changed using a special cable 'Amberlink'.The configuration using Amberlink
is given in a separate manual available with Amberlink.
2.2
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 : 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.
3
General information
3.1
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
3
V3.0
User Manual`
