Siemens siprotec 7SD5 User Manual

4.14 Time Overcurrent Protection
555
7SD5 Manual
C53000-G1176-C169-1
4.14 Time Overcurrent Protection
Operating Modes
Characteristics
Definite Time High Set Current Stage
Definite Time Overcurrent Stage
As emergency overcurrent protection or back-up overcurrent protection
Emergency overcurrent protection with differential
and distance protection
Effective when the differential protection system is blocked
(e.g. because of a failure of the device communication) and
the
distance protection system is blocked as well, e.g. because of
a trip of the voltage transformer mcb (via binary input), a mea-
suring voltage failure or a pickup of the fuse failure monitor
Emergency overcurrent protection with differential
protection (distance protection not configured)
Effective when the differential protection system is blocked
(e.g. because of a failure of the device communication)
Emergency overcurrent protection with distance pro-
tection (differential protection not configured)
Effective when the distance protection system is blocked, e.g.
because of a trip of the voltage transformer mcb (via binary
input), a measuring voltage failure or a pickup of the fuse
failure monitor
Back-up overcurrent protection operates independent of any events
Definite dime stages (definite) I
Ph
>>,3I
0
>>, I
Ph
>, 3I
0
>
Inverse time stages (IDMT) I
P
, 3I
0P
; one of the characteristics according to
Figure 4-1 to 4-3
can be selected
Pickup value I
Ph
>> (phases) for I
N
= 1 A 0.10 A to 25.00 A
or ∞ (ineffective)
Increments 0.01 A
for I
N
= 5 A 0.50 A to 125.00 A
or ∞ (ineffective)
Pickup value 3I
0
>> (earth) for I
N
= 1 A 0.05 A to 25.00 A
Or ∞ (ineffective)
Increments 0.01 A
for I
N
= 5 A 0.25 A to 125.00 A
Or ∞ (ineffective)
Pickup value
IPh
>> (phases) 0.00 s to 30.00 s
Or ∞ (ineffective)
Increments 0.01 s
Delay T
3I0
>> (earth) 0.00 s to 30.00 s
Or ∞ (ineffective)
Increments 0.01 s
Dropout Ratio Approx. 0.95 for I/I
N
≥ 0.5
Pickup times (fast relays/high-speed relays) approx. 30/25 ms
Dropout times Approx. 30 ms
Tolerances Currents 3 % of setting value or 1 % nominal current
Times 1 % of setting value or 10 ms
The set times are pure delay times
Pickup value I
Ph
> (phases) for I
N
= 1 A 0.10 A to 25.00 A
Or ∞ (ineffective)
Increments 0.01 A
for I
N
= 5 A 0.50 A to 125.00 A
Or ∞ (ineffective)
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Siemens siprotec 7SD5 Specifications

General

Brand	Siemens
Model	siprotec 7SD5
Category	Relays
Language	English