VAMP 259 - Power Protection

Technical description
9 Technical data
9.3 Protection stages
VM259.EN007
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289
NOTE! f< if device restarts for some reason there will be no trip even if the
frequency is below the set limit during the start up (Start and trip is
blocked). To cancel this block, frequency has to visit above the set limit.
Underfrequency stages f< and f<<
Frequency measuring area
16.0 - 75.0 Hz
Current and voltage meas. range
45.0 – 65.0 Hz
Frequency stage setting range
40.0 – 64.0 Hz
Low voltage blocking
10 – 100 %Un *)
Definite time function:
-operating time
0.10
**)
- 300.0 s (step 0.02 s)
Undervoltage blocking
2 – 100 %
Starting time
<100 ms
Reset time
<120 ms
Reset ratio
1.002
Reset ratio (LV block)
Instant (no hysteresis)
Inaccuracy:
- starting
±20 mHz
- starting (LV block)
3% of the set value or ±0.5 V
- operating time
±1% or ±30 ms
*) Suitable frequency area for low voltage blocking is 45 - 65 Hz. Low voltage blocking is
checking the maximum of line to line voltages.
**) This is the instantaneous time i.e. the minimum total operational time including the fault
detection time and operation time of the trip contacts.
Rate of change of frequency (ROCOF) stage df/dt> (81R)
Pick-up setting df/dt
0.2 – 10.0 Hz/s (step 0.1 Hz/s)
Definite time delay (t> and t
Min
> are equal):
- operating time t>
0.14
**)
– 10.00 s (step 0.02 s)
Inverse time delay (t> is more than t
Min
>):
- minimum operating time t
Min
>
0.14
**)
– 10.00 s (step 0.02 s)
Starting time
Typically 140 ms
Reset time
t>
Inaccuracy:
- starting
10% of set value or ±0.1 Hz/s
- operating time(overshoot ≥ 0.2 Hz/s)
±35 ms, when area is 0.2 – 1.0 Hz/s
**) This is the instantaneous time i.e. the minimum total operational time including the fault
detection time and operation time of the trip contacts.
NOTE! ROCOF stage is using same low voltage blocking with frequency stages.
9.3.5. Power protection
Reverse power and under-power stages P<, P<< (32)
Pick-up setting range
200.0 ... +200.0 %Pm
Definite time function:
- Operating time
0.3 – 300.0 s
Start time
Typically 200 ms
Reset time
<500 ms
Reset ratio
1.05
Inaccuracy:
- Starting
±3 % of set value or ±0.5 % of rated value
- Operating time at definite time function
±1 % or ±150 ms
NOTE! When pick-up setting is +1 … +200% an internal block will be activated if
max. voltage of all phases drops below 5% of rated.