ABB RELION RET670 Applications Manual page 572

Section 9
Current protection
566
Table 42: Inverse time characteristics
Curve name
ANSI Extremely Inverse
ANSI Very Inverse
ANSI Normal Inverse
ANSI Moderately Inverse
ANSI/IEEE Definite time
ANSI Long Time Extremely Inverse
ANSI Long Time Very Inverse
ANSI Long Time Inverse
IEC Normal Inverse
IEC Very Inverse
IEC Inverse
IEC Extremely Inverse
IEC Short Time Inverse
IEC Long Time Inverse
IEC Definite Time
User Programmable
ASEA RI
RXIDG (logarithmic)
See chapter "Inverse time characteristics" in Technical Manual for the description of
different characteristics
tPCrv, tACrv, tBCrv, tCCrv: Parameters for customer creation of inverse time
characteristic curve (Curve type = 17). The time characteristic equation is:
æ
ç
A
ç
[ ]
=
t s
ç
æ ö
i
ç
ç ÷
è è Pickup N _ ø
EQUATION2031-ANSI V1 EN-US
tINNonDir is the definite time delay for the non directional ground fault current
protection, given in s.
OpVN is set Enabled to activate the trip function of the residual over voltage
protection.
ö
÷
÷
+ ×
B InMult
÷
p
÷
-
C
ø
1MRK 504 163-UUS A
(Equation 449)
Transformer protection RET670 2.2 ANSI
Application manual