VAMP 52 - Page 221

Technical description 9 Technical data 9.3 Protection sta
g
es
VM50.EN004 VAMP 24h support phone +358 (0)20 753 3264
221
Directional intermittent transient earth fault stage I
0T
>
(67NT)***
Input selection for I
0
peak signal I
01
Connectors X1-7&8
I
0
peak pick up level (fixed) 0.005 x I
0n
@ 50 Hz
U
0
pickup level 10 – 100 % U
0n
Definite operating time
0.12  300.00 s (step 0.02)
Intermittent time
0.00  300.00 s (step 0.02)
Start time <60 ms
Reset time <60 ms
Reset ratio (hysteresis) for U
0
0.97
Inaccuracy:
- starting ±3% for U
0
. No inaccuracy defined for I
0
transients
- time ±1% or ±30 ms
*)
*) The actual operation time depends of the intermittent behaviour of the fault and the
intermittent time setting.
***) Only when measurement option is 1Line (line-to-line voltage) or 1Phase (phase-to-neutral
voltage). A complete three phase voltage protection is not possible with VAMP 52.
Directional earth fault stages I
0
>, I
0
>> (67N)
NOTE! This is only available in voltage measurement mode U
0
.
Pick-up current 0.01 – 20.00 x I
0n
( up to 8.00 for inputs other
than I
0Calc
)
Start voltage 1 – 20 %U
0n
Input signal I
0
( input X6- 7 & 8 or X6- 7 & 9)
I
0Calc
( = I
L1
+I
L2
+I
L3
)
Mode Non-directional/Sector/ResCap
Base angle setting range
-180 to + 179
Operation angle
±88
Definite time function:
- Operating time 0.10
**)
– 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 T
p
0.05 - 20.0
Start time Typically 60 ms
Reset time <95 ms
Reset ratio 0.95
Inaccuracy:
- Starting (rated value I
n
= 1 .. 5A) ±3% of the set value or ±0.5% of the rated
value
- Angle
±2
- Operate time at definite time function ±1% or ±30 ms
- Operate time at IDMT function ±5% or at least ±30 ms (I< 50 x I
n
)
*) 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.
Only in U
0
mode
Limitations:
 The maximum measured current is 5 x Rated current (I
0n
or I
02n
).
 This limits the scope of inverse delays if the setting is more than the
maximum measured current divided by 20.