VAMP 135 - Underfrequency Protection F<, F<< (81 L)

VAMP 135 Over-, under-, residual voltage and
frequency relay
Technical description
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14
VAMP 24h support phone : +358 (0)20 753 3264 VM135.EN008
Parameter
ParameterParameter
Parameter Value
ValueValue
Value Unit
UnitUnit
Unit Default
DefaultDefault
Default Description
DescriptionDescription
Description
LVBlck 2…100 %Un 40 Configurable low
voltage blocking limit.
Common for f><, f<
and f><><, f<<
Measured and recorded values of the overfrequency and
underfrequency stages:
f><, f>><< (81)
f><, f>><< (81)f><, f>><< (81)
f><, f>><< (81)
Parameter
ParameterParameter
Parameter Value
ValueValue
Value Unit
UnitUnit
Unit Description
DescriptionDescription
Description
Measured
value
f Hz Frequency
SCntr - Start counter (Start) reading
TCntr - Trip counter (Trip) reading
Flt Hz The ma><. fault value
Recorded
values
EDly % Elapsed time as compared to
the set operating time; 100%
= tripping
2.3.5. Underfrequency protection f<, f<< (81L)
The underfrequency unit comprises two separately adjustable
frequency stages (stage f< and f<<). The protection stages
operate with definite time characteristics.
The overfrequency unit measures the frequency based on the
measured voltages.
The relay starts, if the actual value for the frequency goes
below the setting value. If the underfrequency situation
continues after the start time has elapsed, the relay trips.
&
t
&
&
f
fplohko
ts
tr
>
Blocking
Setting
f<s
Delay
Start
Trip
Event
register
Enable
events
Event
register
Figure 2.3.5-1. Block diagram of the underfrequency stages f< and f<<