Siemens Reyrolle 7SR5 Manual page 234

Protection and Automation Functions
5.14 51 Time-Delayed Overcurrent – Phase
Parameter: Char
•
Default setting: IEC NI (IEC normal inverse)
This setting defines the characteristic of the inverse curve. Standard ANSI and IEC curves are provided as
standard. The characteristic curves and associated formulas are shown in
Custom (user defined) curves can be configured in Reydisp Manager and added to the device configura-
tion. The custom curve will appear as an additional option in the Char setting list using the name that is
entered in Reydisp Manager for all elements for which the curve is applicable.
The characteristic can also be set as DTL, see 51-n Delay.
The characteristic should be set to suit the individual application.
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: 51-n 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: 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 5-20
This is traditionally used with recloser systems only and otherwise is recommended to be left at the
default setting of 0 s.
234
Minimum Operating Time of the Curve
10 Technical
Reyrolle 7SR5, Transformer Protection Device, Device Manual
C53000-G7040-C015-1, Edition 11.2019
Data.