METERING
6.4.2 Transformer
6.4.2.1 Differential and restraint currents
ACTUAL VALUES METERING TRANSFORMER DIFFERENTIAL AND RESTRAINT
DIFFERENTIAL AND
RESTRAINT
6
The metered differential current, restraint current, second harmonic current, and fifth harmonic current are displayed for
each phase. See the Percent Differential section in chapter 5 for details on how these values are calculated.
If differential current in any phase is below the hard-coded cutoff of 0.04 pu, then the differential, 2nd harmonic, and 5th
harmonic currents are forced to zero.
6.4.2.2 Thermal elements
ACTUAL VALUES METERING TRANSFORMER THERMAL ELEMENTS
THERMAL
ELEMENTS
6-16
REFERENCE WINDING:
Winding 1
DIFF PHASOR Iad:
0.000 pu
0.0°
REST PHASOR Iar:
0.000 pu
0.0°
DIFF 2ND HARM Iad:
0.0% fo
0.0°
DIFF 5TH HARM Iad:
0.0% fo
0.0°
DIFF PHASOR Ibd:
0.000 pu
0.0°
REST PHASOR Ibr:
0.000 pu
0.0°
DIFF 2ND HARM Ibd:
0.0% fo
0.0°
DIFF 5TH HARM Ibd:
0.0% fo
0.0°
DIFF PHASOR Icd:
0.000 pu
0.0°
REST PHASOR Icr:
0.000 pu
0.0°
DIFF 2ND HARM Icd:
0.0% fo
0.0°
DIFF 5TH HARM Icd:
0.0% fo
0.0°
TOP OIL °C:
70°C
HOTTEST-SPOT °C:
130°
AGING FACTOR:
1.2
DAILY RATE LOL:
15 hrs
XFMR LIFE LOST:
100000 hrs
T35 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: ACTUAL VALUES