Manual
10-6 Technical Data
865-UM001A-EN-P – July 2009
Non-directional Current Protection
Table 10.17 – Overcurrent Stage I>, I’> (50/51)
Pick-up current 0.10 – 5.00 x I
mode
Definite time function: DT
- Operating time 0.08
– 300.00 s (step 0.02 s)
IDMT function:
- Delay curve family (DT), IEC, IEEE, RI Prg
- Curve type EI, VI, NI, LTI, MI…depends on the family
- Time multiplier k 0.05 – 20.0, except
0.50 – 20.0 for RXIDG, IEEE and IEEE2
Start time Typically 60 ms
Reset time <95 ms
Retardation time <50 ms
Reset ratio 0.97
Transient over-reach, any τ
<10 %
Inaccuracy:
- Starting ±3% of the set value
- Operating time at definite time function ±1% or ±30 ms
- Operating time at IDMT function ±5% or at least ±30 ms
EI = Extremely Inverse, NI = Normal Inverse, VI = Very Inverse, LTI = Long Time Inverse
MI= Moderately Inverse
This is the instantaneous time i.e. the minimum total operational time including the fault
detection time and operation time of the trip contacts.
Table 10.18 – Overcurrent Stages I>> and I’>> (50/51)
Pick-up current 0.10 – 20.00 x I
mode
(I>>)
Definite time function:
0.04
– 300.00 s (step 0.01 s) - Operating time
Start time Typically 60 ms
Reset time <95 ms
Retardation time <50 ms
Reset ratio 0.97
Transient over-reach, any τ
<10 %
Inaccuracy:
- Starting ±3% of the set value
- Operation time ±1% or ±25 ms
This is the instantaneous time i.e. the minimum total operational time including the fault
detection time and operation time of the trip contacts.