Cellwatch Frontier - Page 99

Cellwatch Frontier System Installation & User Manual
Section III – Configuration Build and Hardware Integration Guide-99
CT types
 Discharge only – Usually implemented with standard CT rated at +/-50 to +/-1000A. Used
primarily for monitoring precise current readings on higher discharge load events.
 Charge only – A CT dedicated to monitoring low float charge currents at a higher precision and
resolution.
Note: A current transducer that is configured as a discharge CT can also be used to measure a
recharge current, typically up to 20% of the current transducer’s capacity.
Capacity
The capacity of the CT is a manufacturing specification that determines how high of a current reading
the CT can measure. This is generally noted on the side of the physical CT. Check the CT being used for
its capacity specification.
Assigning properties
The CTs are numbered based on their port location. Multiple CTs can be assigned to a single string and
the output will be a “Logical” data return. Logical CT data is based on which CT is being implemented
according to the state of charge.
If two CTs are assigned to a single string, they will need to be assigned separate types. You cannot have
two of the same type on one string. If a string has a charge CT and discharge CT assigned to it, no other
CTs can be assigned to it.
Reading
The value displays real-time readings from any current transducers connected to the Frontier unit.
These readings can be used to verify the configuration is correct and to assess whether a CT should be
zeroed.
Zero CT
Zeroing a current transducer is setting the baseline for the current readings. Before zeroing a CT, be sure
that the CT is removed from the bus/charger cable so that no current is flowing through. Once the
reading has settled, press the Zero CT button next to the corresponding CT number.
After pressing the Zero CT button, the current state of the readings in the CT are set to zero and any
changes to the magnetic field from that point will be considered actual current readings from the
charger cable. The Zero CT button can be used at any time to recalibrate a current transducer.
Be sure to press the Save button before leaving the page to save any changes that were made.
Float Charging Current Probe (FCCP)
A standard CT used for measuring discharge current is not sensitive enough to measure float charge
current accurately. When an accurate float charge current measurement is required, a Float Charging
Current Probe (FCCP) should be used. The FCCP can measure typical float currents of 50-100mA with
higher precision and has a measurement range of 0-5A.