The mathematical equation is I²t = constant.
And generally the time tripping is given at 6 Ir.
For example the Micrologic 2 for NSX gives the tripping time 16s at 6Ir.
Then what’s about time tripping at 2Ir?
I²t = I’²t’
t = (6/2)² x 16 = 144 s
This mathematical relationship is available only in long time delay of course when you reach
the Isd (short circuit) threshold it is no longer available.
And generally the time tripping is given at 6 Ir.
For example the Micrologic 2 for NSX gives the tripping time 16s at 6Ir.
Then what’s about time tripping at 2Ir?
I²t = I’²t’
t = (6/2)² x 16 = 144 s
This mathematical relationship is available only in long time delay of course when you reach
the Isd (short circuit) threshold it is no longer available.
Released for: Schneider Electric India
