Signals - ABB RELION REX640 Technical Manual

1MRS759142 C
7.2.7
REX640
Technical Manual
respect to the hot-spot temperature for a sample transformer is plotted in
Here, 110 °C is taken as the rated hot-spot temperature at which point an ageing
acceleration factor of 1.0 is achieved.
GUID-292D8D93-7FD6-4967-B751-CB1E3370C48F V1 EN
Figure 699: Variation of insulation ageing factor with hot-spot temperature
(Graph produced using values from Table 11 of IEEE Std.
C57.91-1995)
The variation of insulation life with respect to the hot-spot temperature depends upon
the type of insulation paper used. Thermally upgraded insulation paper neutralizes the
production of acids caused by the hydrolysis of the material over the lifetime of the
transformer and slows down insulation ageing when compared to the normal
insulation paper (IEC 60076-7). The proper selection of insulation paper type is
needed for better accuracy of loss of life calculation.
In certain cases, it is necessary to monitor the loading of the transformer over a defined
time period. For example, during a planned overloading of a transformer for a period
of one month. In such cases it is important to know the ageing rate during that period
of overload rather than the overall loss of life transformer. Hence, an additional output
on average ageing rate over a settable average ageing period is provided in the
function.
The function can be applied for new transformers and also for transformers already in
service using the Initial loss of life setting.

Signals

Table 1202: HSARSPTR Input signals
Name Type
I3P SIGNAL
TOIL_TEMP FLOAT32
AMB_TEMP FLOAT32
BLOCK BOOLEAN
RESET BOOLEAN
RST_AVGAGING BOOLEAN
Condition monitoring functions
Default Description
- Three-phase currents
0 Measured top oil temperature
0 Measured ambient temperature
0=False Block signal for activating the blocking mode
0=False Reset loss of life calculation
0=False Reset average ageing rate calculation
Section 7
Figure 699.
1283