VAMP 150 - Undercurrent Protection I< (37)

VAMP 150 Motor protection relay
Technical Description
VAMP Ltd
18
Vamp 24h support phone : +358 (0)20 753 3264 VM150.EN005
2.2.6. Undercurrent protection I< (37)
The three-phase undercurrent unit measures the fundamental
frequency component of the phase currents.
The stage I< can be configured for definite time characteristic.
The undercurrent stage is protecting rather the device driven
by the motor e.g. a submersible pump, than the motor itself.
Parameters of the undercurrent stage:
I< (37)
I< (37)I< (37)
I< (37)
Parameter:
Parameter:Parameter:
Parameter: Value/unit:
Value/unit:Value/unit:
Value/unit:
Measured
value
IL
MIN
A Min. value of phase currents
IL1..IL3 in primary value
I< xI
MOT
Setting value as per times I
MOT
Setting
values
t< s Operation time [s]
SCntr Start counter (Start) reading
TCntr Trip counter (Trip) reading
1-N, 2-N
3-N
Fault type/single-phase fault
e.g.: 1-N = fault on phase L1
1-2, 2-3
1-3
Fault type/two-phase fault
e.g.: 2-3 = fault between L2
and L3
Type
1-2-3 Fault type/three-phase fault
Flt % Min. value of fault current as
per times I
MOT
Load % 1s mean value of pre-fault
currents IL1—IL3
Recorded
values
EDly % Elapsed time as compared to
the set operate time, 100% =
tripping
2.2.7. Sensitive earth-fault protection I
0
>(50/51N)
The earth-fault unit of the motor protection relay VAMP 150 is
provided with two energizing inputs rated 5 A and 1 A.
The earth-fault unit measures the fundamental frequency
component Io. In the VAMP 150 relay this means that the
degree of attenuation of the third harmonic is at least 60 dB,
which contributes to the extremely high accuracy of the earth-
fault protection.
Stage I
0
> can be configured for definite time characteristic.
Stage I
0
>> can be configured for definite time or inverse time
operation characteristic.