GE P24DM, Technical Manual

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3 PERFORMANCE OF CURRENT PROTECTION FUNCTIONS
3.1 THREE-PHASE OVERCURRENT PROTECTION
IDMT pick-up 1.05 x S/-5%
DT Pick-up S/- 5%
Drop-off (IDMT and DT) 0.95 x s/- 5%
IDMT operation (for IEC and UK curves)
+/- 5% or 60 ms, whichever is greater (1.05 – <2) Is
+/- 5% or 40 ms, whichever is greater (2 – 20) Is
IDMT operation (IEEE and US curves)
For TD setting < 100s +/- 5% or 60 ms, whichever is greater (1.05 – <2) Is
+/- 5% or 40 ms, whichever is greater (2 – 20) Is
IDMT operation (IEEE and US curves)
For TD setting > 100s
+/- 15% (1.05 - 20) Is
Disengagement < 40 ms
DT operate
+/- 2% or 70 ms, whichever is greater (1.05 – <2) Is
+/- 2% or 50 ms, whichever is greater (2 – 20) Is
DT reset S/- 5%
Repeatability +/- 2.5%
Overshoot of overcurrent elements <30 ms
3.1.1 THREE-PHASE OVERCURRENT DIRECTIONAL PARAMETERS
Directional boundary accuracy (RCA +/-90%) +/-2° with hysteresis <3°
IDMT operate
+/- 5% or 70 ms, whichever is greater (1.05 – <2) Is
+/- 2% or 50 ms, whichever is greater (2 – 20) Is
Disengagement < 40 ms
DT operate
+/- 2% or 80 ms, whichever is greater (1.05 – <2) Is
+/- 2% or 60 ms, whichever is greater (2 – 20) Is
DT reset S/-5%
3.1.2 THERMAL OVERLOAD PROTECTION
Setting accuracy ±5%
Reset 97% of thermal setting ±5%
Thermal alarm Pick-up Calculated trip time ±5% or 40 ms whichever is greater
Cooling time constant typical accuracy ±5% of theoretical
Repeatability <2.5%
3.2 EARTH FAULT PROTECTION
Measured and Derived
IDMT pick-up 1.05 x S/-5%
Chapter 21 - Technical Specifications P24xM
434 P24xM-TM-EN-2.1