ABB REB670 - Page 186

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.
txMin: Minimum trip 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.
MultPUx: Multiplier for scaling of the current setting value. If a binary input signal
ENMULTx (enableMultiplier) is activated the current operation level is increased by
this setting constant. Setting range: 1.0-10.0
ANSI10000058-1-en.vsdx
Trip time
Pickup current
tx
txMin
ANSI10000058 V1 EN-US
Figure 88: Minimum pickup current and trip time for inverse time characteristics
In order to fully comply with the definition of the curve, the setting parameter txMin
shall be set to a value equal to the operating time of the selected inverse curve for
twenty times the set current pickup value. Note that the operate time is dependent on
the selected time multiplier setting kx.
ResetTypeCrvx: The reset of the delay timer can be made as shown in Table
27.
Section 7 1MRK 505 370-UUS A
Current protection
180 Busbar protection REB670 2.2 ANSI
Application manual