jbartos
Could you please elaborate the electromagnetic force awareness,does it mean that we should compare the I^2t of contactor (25^2)x0.01 s with contactor strength(4^2)x 1 s ? which from this,it is enough.
How about in case of let-through RMS current of fuse is still higher than breaking capacity of contactor,does the contactor short time rating lower than the let-through RMS current make any harm to contactor before fuse break the current.For example if short circuit RMS current of system is 25...
Does the protection trip come from ground fault relay ?,Do the CT connected with ground fault relay by three CTs of each phase as residual connected ? This kind of problem is common for ground fault connection from three phase CTs.The unbalance occur around 1.0 to 1.5 sec. as you experienced...
Could anyone tell me how to size the autotransformer size for starting of 6.0 kV,50Hz,1600 kW induction motor by autotransformer start method.The tap voltage required is 80%,65% and 50% of nominal line voltage.
Thank you
Can anyone know how to calculate the transformer thermal damage curve for transformer designed and manufactured according to IEC 60076.I have checked and found only ANSI short circuit withstand curves/equation but can not find IEC short circuit withstand curve/equation.Or can I use ANSI...
Hi friend,
I have faced the problem of generator protection setting of back up underimpedance protection for generator protection as follows;
1)First theory: I have found one relay engineer set this 21 mho function having two zones setting as followings,1st zone set to cover in excess of...
I wonder one thing that the relay trip due to overvoltage or current discharge through LA. The tripping due to overvoltage is unlikely to happen due to the overvoltage relay has time delay normally be set at 2 or 3 sec. typically which the surge overvoltage occur in very short time in microsec...
