Line Application Example - ABB REC670 Applications Manual

Section 8
Current protection
8.4.3.6
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EQUATION1722 V1 EN-US
Further description can be found in the technical reference manual.
tPRCrvx, tTRCrvx, tCRCrvx: Parameters for user programmable of inverse reset time
characteristic curve. Further description can be found in the technical reference
manual.

Line application example

Four step residual overcurrent protection can be used in different ways. Below is
described one application possibility to be used in meshed and effectively grounded
systems.
The protection measures the residual current out on the protected line. The protection
function has a directional function where the polarizing voltage (zero-sequence
voltage) is the polarizing quantity.
The polarizing voltage and current can be internally generated when a three-phase set
of voltage transformers and current transformers are used.
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1MRK 511 401-UUS A
(Equation 38)
M15282-184 v8
Bay control REC670 2.2 ANSI
Application manual