Parameter
Range
Zero sequence current
Enable
Not enabled, Enabled
Not enabled
Action
Warning
3.4.14 [Source] over-frequency (ANSI 81O)
Protection
IEC symbol (IEC60617)
ANSI (IEEE C37.2)
IEC 61850
Operate time
Over-frequency
f>, f>>
81O
PTOF
< 100 ms
The alarm response is based on the lowest fundamental frequency (based on phase voltage),
from the source. This ensures that the alarm only activates when all of the phase frequencies
are above the set point.
Set
point
Value
time
Delay
Configure the parameters under
Configure > Parameters > [Source] > Frequency protections > Over-frequency #
, where # is 1
or 2.
Table 3.43
Default parameters
Parameter
Range
Over-frequency 1
Over-frequency 2
Set point
80 to 120 % of nominal frequency
105 %
107 %
Delay
0.00 s to 1 h
5.00 s
3.00 s
Enable
Not enabled, Enabled
Enabled
Enabled
Latch
Not enabled, Enabled
Not enabled
Enabled
Action
Warning
Block
Table 3.44
Default inhibits
Controller type
Inhibit(s)
GENSET
Generator breaker closed
EMERGENCY genset
Generator breaker closed, Tie breaker closed
SHAFT generator
Shaft breaker closed
SHORE connection
Shore breaker closed
3.4.15 [Source] under-frequency (ANSI 81U)
Protection
IEC symbol (IEC60617)
ANSI (IEEE C37.2)
IEC 61850
Operate time
Under-frequency
f<, f<<
81U
PTUF
< 100 ms
DESIGNER'S HANDBOOK 4189340911K UK
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