Parameter:
Time Mult (IEC/ANSI)
•
Default setting:
1
This setting defines the time multiplier that is applied to the selected current curve. For IEC curves this
value is traditionally in the range 0 to 1.6 and for ANSI curves a value of 0 to 15 is typically applied.
Parameter:
Delay (DTL)
•
Default setting:
5 s
This is the time delay setting for the element when the
Char
is selected as DTL. This should be set to suit
the individual application. This setting is not used if any other characteristic curve is selected.
Parameter:
51N-n Min Operate Time
•
Default setting:
0 s
With the parameter a minimum operate delay time can be selected. The operate delay time of
inverse‑time characteristic curve never falls below the minimum operate delay time.
[dw_7SR5_minimumoperatingtimecurve, 1, en_US]
Figure 5-27
Minimum Operating Time of the Curve
This is traditionally used with recloser systems only and otherwise is recommended to be left at the
default setting of 0 s.
Parameter:
Follower DTL
•
Default setting:
0 s
This setting allows an additional time to be added to that achieved by the selected characteristic curve. It
is applied as a DTL time after the operate state from the curve is achieved. With this setting, the whole
curve is shifted linearly on the time axis by this additional definite time.
This is traditionally used with recloser systems only and otherwise is recommended to be left at the
default setting of 0 s.
Protection and Automation Functions
5.16 51N Time-Delayed Earth Fault – Calculated
258
Reyrolle 7SR5, Transformer Protection Device, Device Manual
C53000-G7040-C015-1, Edition 11.2019
