Siemens Reyrolle 7SR45 Argus Device Manual page 54

Functions
3.5 Time-Delayed Derived Earth Fault Protection (51N)
The following characteristic curves are supported by 51N-n:
•
DTL
•
IEC-NI
•
IEC-VI
•
IEC-EI
•
IEC-LTI
•
ANSI-MI
•
ANSI-VI
•
ANSI-EI
Operating time for IEC
Operating time for IEEE/ANSI
Reset time for IEC/IEEE/ANSI
Table 3-2
Curve Type
IEC-NI
IEC-VI
IEC-EI
IEC-LTI
IEEE/ANSI-MI
IEEE/ANSI-VI
IEEE/ANSI-EI
where,
I - Fault-current Magnitude
I - Pickup setting
S
T - Time multiplier
m
Application and Settings Notes
Gn 51N-n Element
Default setting: Disabled
This setting is used to allow the element to be switched on and off if it is not required. A separate setting is
provided for each element. These settings can be used to select the number of elements required.
Parameter State
Disabled
Enabled
54
Constants for Operating-Curve and Reset-Curve Characteristics
K α
0.14 0.02
13.5 1.0
80 2.0
120 1.0
– –
– –
– –
Description
The element is inactive.
The element is active.
Operating Curve
P A
– –
– –
– –
– –
0.02 0.0515
2.0 19.61
2.0 28.2
Reset Curve
B R n
– 9.7 2
– 43.2 2
– 58.2 2
– 80 2
0.114 4.85 2
0.491 21.6 2
0.1217 29.1 2
Reyrolle, 7SR45, Device Manual
C53000-G7040-C101-2, Edition 09.2020