Technical description
2 Protection functions
2.1 Maximum number of protection
stages in one application
VM259.EN007
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49
2.
Protection functions
Each protection stage can independently be enabled or disabled
according to the requirements of the intended application.
2.1.
Maximum number of protection
stages in one application
The device limits the maximum number of enabled stages to
about 30, depending of the type of the stages. For more
information, please see the configuration instructions in
chapter 2.4 in the Operation and Configuration instruction.
2.2.
List of protection functions
IEEE/
ANSI code
IEC symbol Function name
Main protection functions
21
Z<
Short circuit distance protection
21N
Ze<
Earth-Fault distance protection
87
dI>
Line differential protection
85
Pilot signalling
Back-up protection functions
67
I
dir
>, I
dir
>>,
I
dir
>>>, I
dir
>>>>
Directional overcurrent protection
67N
Directional earth fault protection
50/51
3I>, 3I>>, 3I>>> Non directional overcurrent protection
50N/51N
I
0
>, I
0
>>, I
0
>>>,
I
0
>>>>
Non directional earth fault protection
Supporting functions
79
0
1
Autoreclosing
25
∆f, ∆U, ∆φ
Synchrocheck
50ARC/
50NARC
ArcI>, ArcIO>
Optional arc fault protection
50BF
CBFP
Circuit-breaker failure protection
81R
df/dt
Rate of change of frequency (ROCOF) protection
46R
I
2
/I
1
>
Broken line protection
37
I<
Undercurrent protection
59N
U
0
>, U
0
>>
Zero sequence voltage protection
49
T>
Thermal overload protection
59
U>, U>>, U>>> Overvoltage protection
27
U<, U<<, U<<< Undervoltage protection
32
P<, P<<
Reverse and underpower protection
81H/81L
f><, f>><<
Overfrequency and underfrequency protection
81L
f<, f<<
Underfrequency protection
99
Prg1...8
Programmable stages