Siemens Reyrolle 7SR45 Argus Device Manual page 55

Gn 51N-n Setting
Default setting: 0.50 ⋅ I
This setting defines the operating current threshold of the element. The applied phase current must exceed
this setting by a factor of 1.10x for pickup of the element. The operation timing will then be dependent on the
selected characteristic for the element setting. The element pickup will reset when the current is below 1.00x
the setting and the reset characteristic will be applied. This factor is always applied for 51N elements including
when the Char is selected as DTL. This setting should be set to suit the individual application.
Gn 51N-n Char
Default setting: IEC-NI
This setting defines the characteristic of the inverse curve. Standard ANSI and IEC curves are provided as
standard. The characteristic can also be set as DTL. This increases the number of DTL elements that are avail-
able if more are required. 51N elements have a configurable reset characteristic that can be set as DTL. A 51N
element can provide a DTL operate and DTL reset characteristic if that is required.
The characteristic should be set to suit the individual application.
Gn 51N-n Time Mult (if Char is set as IEC or ANSI)
Default Setting: 1.00
This setting defines the time multiplier that is applied to the selected current curve. For IEC curves, this value is
traditionally in the range of 0.01 to 10. For ANSI curves, a value of 0.01 to 10 is typically applied.
Gn 51N-n Delay (if Char is set as DTL)
Default setting: 5.00 s
This is the time delay setting for the element when the Char element 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.
Gn 51N-n MinOperate
Default setting: 0.00 s
With this parameter, a minimum operate delay time can be selected. The operate delay time of the inverse-
time characteristic curve never falls below the minimum operate delay time.
[dw_7SR45_minimumoperatingtimecurve, 1, en_US]
Figure 3-5
This parameter is traditionally used with recloser systems only and otherwise is recommended to be left at the
default setting of 0 s.
Reyrolle, 7SR45, Device Manual
C53000-G7040-C101-2, Edition 09.2020
rated
Minimum Operating Time of the Curve
3.5 Time-Delayed Derived Earth Fault Protection (51N)
Functions
55