ABB RELION RET670 Applications Manual page 558

Section 9
Current protection
552
DirModeSelx: The directional mode of step x. Possible settings are off/nondirectional/
forward/reverse.
Characteristx: Selection of time characteristic for step x. Definite time delay and
different types of inverse time characteristics are available.
Table 41: 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)
The different characteristics are described in the Technical Reference Manual (TRM).
Pickupx: Operation negative sequence current level for step x given in % of IBase.
tx: Definite time delay for step x. The definite time tx is added to the inverse time when
inverse time characteristic is selected. Note that the value set is the time between
activation of the start and the trip outputs.
TDx: Time multiplier for the dependent (inverse) characteristic.
IMinx: Minimum pickup current for step x in % of IBase. Set IMinx below Pickupx for
every step to achieve ANSI reset characteristic according to standard. If IMinx is set
above Pickupx for any step the ANSI reset works as if current is zero when current
drops below IMinx.
1MRK 504 163-UUS A
Transformer protection RET670 2.2 ANSI
Application manual