WAGO 879-3000 4PU, Operating Instructions Manual

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26 WAGO Operating Instructions 4PU/4PS/2PU CT
6.9 Set Transformer Ratio (2PU CT only)
The primary current can be set to 0001 … 9999 A (with a secondary
current of 1 A) or 0005 …
9995 A (with a secondary current of 5 A). The
secondary current can be set to /1 A or /5 A. A transformer ratio of
CT=5/5 A is preset at the factory. The meter offers the option of
adjusting the converter ratio up to 7 times in the password-protected
settings menu (see 6.6.1). A CT history register is created to record all
changes in the CT ratio. For each CT history, there is a specific register
that stores the last transformer ratio and energy readings.
The image below shows that the transformer ratio (called RESETS) has already been changed three times. Three CT ratio
changes require three CT HISTORY REGISTERS. So CT HISTORY -01 0005/5 A; -02 0100/5 A and -03 1100/5 A.
In the first image, entry into the submenu is confirmed with OK in the menu. In the following figures, the entries CT HISTORY
01 - CT HISTORY 03 are displayed by pressing the marked buttons. If other CT_HISTORY REGISTERS are written, they can be
accessed by pressing the right button again.
Note:
CT DEFAULT: CT 0005/5
After the 1st SETTING (RESET), from CT 0005/5 to e.g., CT 0100/5, the 0005/5 ratio is stored in CT HISTORY 01: CT 0005/5.
However, the meter continues to count with the setting CT 0005/5 in the Modbus
®
and display and the values are also shown
in the display under CT HISTORY 01: CT 0005/5. The CT history register is available in Modbus
®
register 6100-619E. In addition,
the last values of the energy values (OBIS codes 1.8.1, 1.8.2 and 2.8.1, 2.8.2) are shown with each CT change in the DISPLAY
of the respective CT ratio. The 7th RESET is retained as the last CT setting.