ABB REB670 Applications Manual page 200

Section 7
Current protection
194
Curve name
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 operate 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.
1MRK 505 337-UUS -
Application manual