Arcteq AQ 200 Series, Инструкция по эксплуатации

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Table. 5.2.1. - 4. Initial data from example connection.
High voltage side CT:
CT primary 800A
CT secondary 1A
HV-side nominal current:
669A
Ring core CT in Input I02:
3I0CT primary 250A
3I0CT secondary 1A
Low voltage side CT:
CT primary 8000A
CT secondary 1A
LV-side nominal current:
5888A
Both CTs are pointing through the transformer (HV-S2 and LV-S2 are pointing to same direction).
Nominal current for both high voltage and low voltage side of the protected transformer are calculated
based on given values under the “Transformer Characteristics” menu, which is located under the
protection main menu. CT module 1 and 2 ratio can be set directly under the same menu, or optionally
under
Measurement
→
Transformers
–menu. Per unit (PU) scaling is automatically set as xed to
“Object In p.u.” in all machine protection relays and it cannot be changed.
Figure. 5.2.1. - 52. Phase current transformer scaling to machine nominal.
As it can be seen in the gure above, the high voltage side nominal current is calculated to be 669.2A
and the low voltage side current is 5888.97A. These nominal currents are calculated as follow:
Per unit values for high –and low voltage side nominal currents can be calculated as shown below:
AQ-T216
Instruction manual
Version: 2.00
47 © Arcteq Relays Ltd