Note
You will get the best results with a combination of current sensors inside each individual BACS string as well as using the sensors
coming with BACS modules. By doing so, more data can be collected and analyzed:
- General voltage
- Internal resistance of the batteries
- temperature of the batteries
- quality and uniformity of the discharge current itself
However, BACS offers you different graduated possibilities for discharge detections:
1. UPS status
The UPS knows the current charge or discharge status and will provide this information for the BACS Webmanager. To
choose this option, the BACS Web Manager must be connected to the UPS. Depending on the BACS design, you can choose
between a single device or a modular solution. Even the combination CS141 slot card with BACS BUS Converter can be
used.
In other cases the connection is possible via the RS232 interface. If you use a UPS with SNMP access, it is also possible to
configure an access via the RFC1628 interface and query the data directly via LAN. Current sensors provide additional
current quality detection
2. If no communication to the UPS is possible, you can get accurate information via the current sensors and the BACS modules.
a. Charge-/Discharge detection
b. Accurate readings on consistent charge and discharge cycles as well as quality and fluctuations of the current.
In this setup, the BACS modules provide voltage values across the batteries and the current sensors provide values about the
current that actually flows per string.
3. If, for logistical reasons, you can only use one current sensor, it will in principle provide an exact charging and discharging
detection source. But with one current sensor, it is just possible to provides a theoretical overview of the quality of the current
that will flow during charge- / discharge processes.
Obey that the current sensors can be used either on the main line before splitting into single strings or inside a single string
after splitting.
a. The main string
At the main string, the total current is measured. You will recognize a very accurate charge / discharge detection as
well as information about internal fluctuation in the current flow, but you will not be able to get informationes about
the strings that may trigger current flow problems.
b. At the single string
Like a main string installation type, you will find a very accurate charge/discharge detection. The difference is, that
the single string installation will measure the real current at this trand the current sensor is installed to. You can use
the multiplier to approximate the value to reality, but it remains as some kind of rough estimate. What you can see
accurate:
If the value for current drops, the problem has to be found in the string where the sensor is installed to. On the other
hand, if the value increases dramatically, there is a problem in one of the other strings. Technically, a more exact
limitation feasible in this constellation is not possible and the accuracy depends on the number of strings you have
installed - With two strings, it is easy to figure out which string causes trouble. With three strings, two strings you
have possible candidates...
4. You can also completely dispense the connection of a UPS as well as the use of current sensor. The charge / discharge
detection can be fully mapped by the BACS modules. The modules measure the internal resistance and the voltage of the
batteries they are installed on. The modules can measure if a charge cycle or discharge cycle is in progress. But it will need
some time. This possibility, however, ignores the current that will flow during charging and discharging.
Reverse Current Direction
The current sensor measures the induced magnetic field coming with directed electron migration through a conductor. Due to the fact
the current sensor can measure bi-directional, the installation direction is crucial:
The magnetic field of this directed electron motion provides information about the direction of electron migration.
With this function, the real magnetic field recognition can be inverted - thus will place charge and discharge recognition into a correct
context. If the current sensor has been installed incorrectly, this function can be used to reverse the current direction and the sensor can
remain in this installation direction.
To Next Page
Loading...
