ABB REB650 Applications Manual page 102

Section 7
Current protection
96
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.
IxMult: 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
Operate time
tx
txMin
IMinx
IEC10000058 V2 EN-US
Figure 39: Minimum operate current and operate 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 13.
Table 13: Reset possibilities
Curve name
Instantaneous
IEC Reset (constant time)
ANSI Reset (inverse time)
The delay characteristics are described in Technical manual. There are some
restrictions regarding the choice of the reset delay.
For the definite time delay characteristics, the possible delay time setting
instantaneous (1) and IEC (2 = set constant time reset).
Current
IEC10000058
Curve index no.
1
2
3
1MRK 505 388-UEN B
Busbar protection REB650 2.2 IEC
Application manual