VAMP Ltd
Generator protection relay
Technical description
VAMP 210
VM210.EN004
Vamp 24h support phone: +358 (0)20 753 3264
19
Parameters of the directional earth-fault protection:
I
0
ϕ
> (67N)
Parameter: Value/unit:
I
0
Res or
I
0
Cap
A
earth-fault current Io as primary
value, input Io1
U
0
%
Residual voltage start value in
proportion to the rated voltage
UoSec
Measured
values
Char Res
or
Cap Resistive or capacitive function to
be carried out, see setting value
ChCtrl
I
ϕ
>
A
Set value as primary value
I
ϕ
>
pu
Residual current start value in
proportion to the rated current
Io1n
t> s
Operating
time
U
0
> %
Residual voltage start voltage in
proportion to the rated voltage
UoSec
Res
earthed network, resistive
component (Iocos
ϕ
) of earth-fault
current is measured
Cap
Non-earthed network, capacitive
component (Iosin
ϕ
) of earth-fault
current is measured
Setting
values
ChCtrl
DI1 – DI6 programmed digital input controls
the Res/Cap selection: 0 = Res, 1 =
Cap
SCntr
Cumulative start counter
TCntr
Cumulative trip counter
Flt
pu
Max. fault current
EDly
Elapsed time as compared to the
set operating time, 100% =
tripping
Angle o
Phase angle between res. voltage
and current
Recorded
values
U
0
%
Max. residual voltage under fault
condition
2.2.5.
Earth fault protection (50N/51N)
The neutral point of a generator is usually connected to ground
using a current limiting impedance. In case this impedance is
limiting the prospective earth fault current significantly lower
than short circuit current, a separate earth fault current
protection is needed.
VAMP 210 has four unidirectional earth fault stages and two
separate energizing inputs for earth fault current i.e. I
01
and
I
02
. The two first stages are using input I
01
, which is normally
connected to a cable CT or inserted to the common return wire
of the three phase current CTs.
