VAMP 257 - Protection Stages Overview; Non-Directional Current Protection (50;51)

VAMP 257 Feeder and motor manager
Technical description
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138
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VM257.EN002
5.3. Protection stages
NOTE! Please see chapter 2.2.2 for explanation of Imode.
5.3.1. Non-directional current protection
Overcurrent stage 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
Start time 60 ms
Reset time <80 ms
Reset ratio 0.97
Inaccuracy:
- Starting ±2% 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 (I< 50 x I
mode
)
*) 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.
Overcurrent stages I>> and I>>> (50/51)
Pick-up current 0.10 – 20.00 x I
mode
(I>>)
0.10 – 40.00 x I
mode
(I>>>)
Definite time function:
0.04
**)
– 300.00 s (step 0.01 s) - Operating time
Start time 60 ms
Reset time <80 ms
Reset ratio 0.97
Inaccuracy:
- Starting ±2% 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.
Stall protection stage (48)
Setting range:
- I
st
>
- I
motSt
1.30 – 10.00 x I
mot
(step 0.01)
1.50 – 10.00 x I
mot
(step 0.01)
Definite time characteristic:
- operating time 1.0 – 300.0 s (step 0.1)
Inverse time characteristic:
- 1 characteristic curve
- Time multiplier tDT>
Inv
1.0 – 200.0 s (step 0.1)
Starting time 60 ms
Resetting time 80 ms
Resetting ratio 0.90
Accuracy:
- operating time ±5% or at ±80 ms