ABB Relion 670 Series Applications Manual page 182

Section 7
Current protection
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.
MultPUx: Multiplier for scaling of the current setting value. If a binary input signal (ENMULTx) is activated
the current operation level is multiplied by this setting constant.
txMin: Minimum operation time for 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.
Operate time
tx
txMin
IEC10000058 V2 EN-US
Figure 99:
ResetTypeCrvx: The reset of the delay timer can be made in different ways. By choosing setting there
are the following possibilities:
Curve name
Instantaneous
IEC Reset (constant time)
ANSI Reset (inverse time)
The different reset characteristics are described in the Technical Reference Manual (TRM). There are
some restrictions regarding the choice of reset delay.
For the independent time delay characteristics the possible delay time settings are instantaneous (1) and
IEC (2 = set constant time reset).
For ANSI 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).
176
IMinx
Minimum operate current and operation time for inverse time characteristics
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Current
IEC10000058
1MRK 505 370-UUS Rev. K
Busbar protection REB670
Application manual