ABB RET670 - Page 451

For IEC inverse time delay characteristics the possible delay time settings are
instantaneous (1) and IEC (2 = set constant time reset).
For the programmable inverse time delay characteristics all three types of reset time
characteristics are available; instantaneous (1), IEC (2 = set constant time reset) and
ANSI (3 = current dependent reset time). If the current dependent type is used settings
pr, tr and cr must be given.
tPCrvx, tACrvx, tBCrvx, tCCrvx: Parameters for programmable inverse time
characteristic curve (Curve type = 17). The time characteristic equation is according to
equation
350:
[ ]
p
A
t s B TD
i
C
ipickup
= + ×
-
æ ö
ç ÷
ç ÷
ç ÷
æ ö
ç ÷
ç ÷
è ø
è ø
EQUATION1722 V1 EN (Equation 352)
Further description can be found in the Technical reference manual (TRM).
tPRCrvx, tTRCrvx, tCRCrvx: Parameters for programmable inverse reset time
characteristic curve. Further description can be found in the Technical reference
manual (TRM).
Common settings for all steps
x means step 1, 2, 3 and 4.
AngleRCA: Relay characteristic angle given in degrees. This angle is defined as shown
in figure 192. The angle is defined positive when the residual current lags the reference
voltage (Vpol = -)
1MRK504116-UUS C Section 3
IED application
445
Application manual