VAMP 259 - Page 283

Technical description
9 Technical data
9.3 Protection stages
VM259.EN007
VAMP 24h support phone +358 (0)20 753 3264
283
Overcurrent stages I>> and I>>> (50/51)
Pick-up current
0.10 – 20.00 x In (I>>)
0.10 – 40.00 x In (I>>>)
Definite time function:
- Operating time
DT
- I>>
0.04
**)
– 1800.00 s (step 0.01 s)
- I>>>
0.04
**)
– 300.00 s (step 0.01 s)
Start time
Typically 60 ms
Reset time
<95 ms
Retardation time
<50 ms
Reset ratio
0.97
Transient over-reach, any 
<10 %
Inaccuracy:
- Starting
±3% of the set value or 5 mA secondary
- 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.
Thermal overload stage T> (49)
Overload factor:
0.1 – 2.40 x In (step 0.01)
Alarm setting range:
60 – 99 % (step 1%)
Time constant Tau:
2 – 180 min (step 1)
Cooling time coefficient:
1.0 – 10.0 xTau (step 0.1)
Max. overload at +40 C
70 – 120 %I
n
(step 1)
Max. overload at +70 C
50 – 100 %I
n
(step 1)
Ambient temperature
-55 – 125 C (step 1
Resetting ratio (Start & trip)
0.95
Accuracy:
- operating time
±5% or ±1 s
NOTE! Stage is blocked when motor has been running for 2 seconds.
Secondary current has to be > 1A in all phases.
Undercurrent protection stage I< (37)
Current setting range:
20 – 70 %In (step 1%)
Definite time characteristic:
- operating time
0.3 – 300.0s s (step 0.1)
Block limit:
15 % (fixed)
Starting time
Typically 200 ms
Resetting time
<450 ms
Resetting ratio
1.05
Accuracy:
- starting
±2% of set value or ±0.5% of the rated value
- operating time
±1% or ±150 ms
NOTE! Stage Blocking is functional when all phase currents are below the block
limit.