Siemens SIPROTEC 7UT633*-* N series - 4.2 Differential Protection

4.2 Differential Protection
435
7UT613/63x Manual
C53000-G1176-C160-2
4.2 Differential Protection
Pickup Values
Time Delays
Figure 4-1 Tripping characteristic of the differential protection
I
diff
differential current = |I
1
+ I
2
|
I
rest
stabilising current = |I
1
| + |I
2
|
I
NObj
Nominal current of protected object
Differential current I
Diff
>/I
NObj
0.05 to 2.00 Steps 0.01
High-current stage I
Diff
>>/I
NObj
0.5 to 35.0
or ∞ (ineffective)
Steps 0.1
Increase of the pickup value when connect-
ing as a factor of I
Diff
>
1.0 to 2.0 Steps 0.1
Add-on restraint on external fault
(I
stab
> setting value)
Action time
I
Add-on
/I
NObj
2.00 to 15.00
2 to 250 cycles
or ∞ (active until dropout)
Steps 0.01
Increments 1 cycle
Trip characteristic see Figure 4-1
Tolerances (with preset characteristic parameters, for 2 sides with 1 measuring location each)
I
Diff
> stage and characteristic 5 % of set value
I
Diff
>> stage 5 % of set value
Delay of I
Diff
> stage T
IDiff>
0.00 s to 60.00 s
or ∞ (no trip)
Steps 0.01 s
Delay of I
Diff
>> stage T
IDiff>>
0.00 s to 60.00 s
or ∞ (no trip)
Steps 0.01 s
Time tolerance 1 % of set value or 10 ms
The set times are pure delay times