Thermal Measurement; Functional Description - Siemens SIPROTEC 4 7UT6 Series Manual

No. Information
30759 φI12=
30760 U4 =
30761 U0meas.=
30762 U0calc.=
30792 φUL1E=
30793 φUL2E=
30794 φUL3E=
30795 φU4=
30796 φUE=

Thermal Measurement

2.22.3
Depending on its configuration, the device can determine and display thermal measurement values.
2.22.3.1

Functional Description

The measured thermal values are listed in
functions has been configured as Enabled. Which measured values are possible also depends on the overload
detection method chosen and, in certain cases, of the number of temperature detectors connected via the
RTD-box.
The hot-spot temperatures are calculated in transformers for each leg. Therefore, temperatures are indicated
with a phase (in the case of Y windings), or with a phase-phase concatenation (D windings). For standard
vector groups, this information correspond to the ends of the windings. In more unusual vector groups (which
are created by phase swapping), the phase assignment in the vector group is not always clear.
The thermal values are referred to the tripping temperature rise. For degrees of temperature there are no
referred values. However, since further processing of such values (in CFC or when transmitted through serial
interfaces) requires values without dimension, arbitrary references have been chosen, which are contained in
Table 2-15 in the column "% conversion".
Table 2-15
Measured values
θ /θ ; θ /θ ; Thermal value of each phase, referred to
L1 OFF L2 OFF
the tripping value
θ /θ 1)
L3 OFF
Thermal resultant value, referred to the
θ/θ 1)
OFF
tripping value
Relative ageing rate L
Ag.rate 2) 3)
Load reserve to hot-spot/ageing alarm
Res Warn 2) 3)
(stage 1)
Load reserve to hot-spot tripping (stage
Res Alarm 2) 3)
θ leg L1; θ leg L2; θ Hot-spot temperature for each phase (Y
winding or Z winding)
leg L3 2) 3)
θ leg L12; θ leg L23; Hot-spot temperature for each phase (D
winding)
θ leg L31 2) 3)
θ RTD 1... θ RTD 12 Temperature measured at the Tempera-
ture detectors 1 to 12
3)
1) only for overload protection with thermal replica (IEC 60255-8): Address 142 THERM. OVERLOAD = th
repl w. sens
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016
Type of
Informa-
tion
MV
MV
MV
MV
MV
MV
MV
MV
MV
Table
Thermische Messwerte
Comments
Phase angle of current I12
Operat. meas. voltage U4
Operat. meas. voltage U0 measured
Operat. meas. voltage U0 calculated
Phase angle of voltage UL1E
Phase angle of voltage UL2E
Phase angle of voltage UL3E
Phase angle of voltage U4
Phase angle of voltage UE
2-15. They can only be displayed if the overload protection
Dimension
% Conversion
%
%
p.u.
%
%
°C or °F
°C or °F
°C or °F
Functions
2.22 Auxiliary Functions
4)
0 °C = 0 %
500 °C = 100 %
0 °F = 0 %
1000 °F = 100 %
285