ABB Relion 670 Series Applications Manual page 158

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
the ANSI reset works as if current is zero when current drops below
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 73: Minimum operate current and operation time for inverse time characteristics
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).
152
IMinx
IMinx is set above Pickupx for any step
IMinx .
Current
IEC10000058
1MRK 511 358-UUS A
Application manual