ABB RET650 Applications Manual page 116

Section 7
Current protection
110
Table 15: 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 or RD (logarithmic)
The different characteristics are described in Technical manual.
Ix>: Operate phase current level for step x given in % of IB.
Ix>Max and Ix>Min should only be changed if remote setting of operation current
level, Ix>, is used. The limits are used for decreasing the used range of the Ix>
setting. If Ix> is set outside Ix>Max and Ix>Min, the closest of the limits to Ix> is
used by the function. If Ix>Max is smaller than Ix>Min, the limits are swapped.
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.
kx: Time multiplier for inverse time delay for step x.
IMinx: Minimum operate current in % of IB for all inverse time characteristics,
below which no operation takes place.
txMin: Minimum operate time for all inverse time characteristics. At high currents
the inverse time characteristic might give a very short operation time. By setting
this parameter the operation time of the step can never be shorter than the setting.
Setting range: 0.000 - 60.000s in steps of 0.001s.
1MRK 504 169-UEN A
Transformer protection RET650 2.2 IEC
Application manual