GE D90 Plus Instruction Manual page 390

CONTROL ELEMENTS
NOTE:
Composite recloser curve example
380
Figure 317: Recloser curve initialization
The multiplier and adder settings only affect the curve portion of the characteristic and not
the MRT and HCT settings. The HCT settings override the MRT settings for multiples of
pickup greater than the HCT ratio.
A composite curve can be created from the GE_111 standard with MRT = 200 ms and HCT
initially disabled and then enabled at eight times pickup with an operating time of 30 ms.
At approximately four times pickup, the curve operating time is equal to the MRT and from
then onwards the operating time remains at 200 ms (see below).
Figure 318: Composite recloser curve with HCT disabled
With the HCT feature enabled, the operating time reduces to 30 ms for pickup multiples
exceeding eight times pickup.
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: PROTECTION