VAMP 259 - Frequency Protection

9.3 Protection stages
9 Technical data
Technical description
288
VAMP 24h support phone +358 (0)20 753 3264
VM259.EN007
Undervoltage stages U<, U<< and U<<< (27)
Setting range
20 – 120%xU
n
Definite time function:
- Operating time U<
- Operating time U<< and U<<<
0.08
*)
– 300.00 s (step 0.02 s)
0.06
*)
– 300.00 s (step 0.02 s)
Undervoltage blocking
0 – 80% x U
n
Start time
Typically 60 ms
Reset time for U<
0.06 – 300.00 s (step 0.02 s)
Reset time for U<< and U<<<
<95 ms
Retardation time
<50 ms
Reset ratio (hysteresis)
Reset ratio (Block limit)
1.001 – 1.200 (0.1  20.0 %, step 0.1 %)
0.5 V or 1.03 (3 %)
Inaccuracy:
- starting
±3% of set value
- blocking
±3% of set value or ±0.5 V
- time
±1% or ±30 ms
*) This is the total operational time including the fault detection time and operation time of the
trip contacts.
Zero sequence voltage stages U
0
> and U
0
>> (59N)
Zero sequence voltage setting range
1 – 60 %U
0n
Definite time function:
- Operating time
0.3 – 300.0 s (step 0.1 s)
Start time
Typically 200 ms
Reset time
<450 ms
Reset ratio
0.97
Inaccuracy:
- Starting
±2% of the set value or ±0.3% of the rated value
- Starting UoCalc (3LN mode)
±1 V
- Operate time
±1% or ±150 ms
9.3.4. Frequency protection
Overfrequency and underfrequency protection stages f><
and f>><< (81H/81L)
Frequency measuring area
16.0 - 75.0 Hz
Current and voltage meas. range
45.0 – 65.0 Hz
Frequency stage setting range
40.0 – 70.0 Hz
Low voltage blocking
10 – 100 %Un *)
Definite time function:
-operating time
0.10**
)
– 300.0 s (step 0.02 s)
Starting time
<100 ms
Reset time
<120 ms
Reset ratio (f> and f>>)
0.998
Reset ratio (f< and f<<)
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.