Siemens Reyrolle 7SR5 Manual page 153

Parameter: 24IT Xn, Yn (7 points)
•
Default settings:
–
X0: 1.10 p.u. Y0: 20000 s
–
X1: 1.14 p.u. Y1: 1200 s
–
X2: 1.16 p.u. Y2: 540 s
–
X3: 1.21 p.u. Y3 240 s
–
X4: 1.24 p.u. Y4: 120 s
–
X5: 1.28 p.u. Y5: 60 s
–
X6: 1.4 p.u. Y6: 20 s
The operate curve plotted from the user values should operate times suitably coordinated with the over-
flux withstand values of the protected plant.
7 over-fluxing pickup/operate time pairs (Xn/Yn) can be set. The default characteristic curve refers to a
standard transformer.
The pickup defined by the user points starts the integration process (weighted counting) of the character-
istic curve.
[dw_thermal_characteristic_curve_tripping_zone, 1, en_US]
The time derived from the characteristic curve and associated with the V/f value is set to 100 %. With
each function call, the time will be increased according to the respective weighted invocation interval. If
the 100 % value is exceeded, tripping is initiated. If the V/f value is changed, the associated time from the
characteristic curve is added as a new 100 % value.
Reyrolle 7SR5, Transformer Protection Device, Device Manual
C53000-G7040-C015-1, Edition 11.2019
Protection and Automation Functions
5.2 24 Overexcitation Protection
153