108 The ESI-Manager user interface
Manual Energy Storage Inverter ESI-S
CT Ratio L1
(a)
Ratio that will be used by the inverter for the CT physically
connected in phase 1 (L1, R, U) of the installation
Remark:
(a)
The first phase has to be acknowledged before the second phase is displayed…
−
After acknowledging the last phase with
, the inverter will automatically
reset and the new values will be taken into account. Pressing
at any time
will interrupt the automatic CT detection process. In single unit inverters, original
CT-values and positions existing prior to the start of the procedure will be
restored. In multi-unit inverters, the new values will be stored in the units for
which the CT setting were already accepted, and will be restored to the initial
value in the other units.
If the CT identification ended unsuccessfully
:
−
The inverter displays an error message indicating the reason for the problem.
gives a list of the possible error messages.
Table 45: Possible error messages during automatic CT identification
ESI-Manager error messages during automatic CT identification
The CT identification found inconsistent CT positions.
The CT identification did not end within an appropriate time frame.
The CT identification required an abnormally high DC voltage.
The most common causes for these messages are:
•
CTs not connected or shorted
•
CTs connected in open loop configuration
•
Usage of an excessive CT ratio (including summation CTs). The CT ratio limit
is set at 20000/5.
−
After acknowledging the error message, the CT values existing before the start
of the process will be restored and the automatic CT detection procedure will be
ended. The unsuccessful CT detection attempt is recorded in the event logging
window.
Conditions under which the automatic CT identification process may give unsatisfactory
results include:
−
The use of CTs with extremely high ratio’s (> 20000/5). This will result in an error
message indicating inconsistent CT positions. In this, the ratio of the summation
CTs that may be present should be included.
−
The presence of a low impedance directly downstream of the inverter connection
although the CTs have been correctly installed upstream of the inverter
connection. This will result in wrong CT ratio’s being found. In that case the
commissioning engineer can easily correct the CT ratio’s found.
−
The use of complex CT arrangements including summing CTs.
