Define what is difference between fuse and breaker?

1178

testing of Vector Group – YNaoD II

2931

what do you mean by type zero control sytem ?Give an practical example of type zero contol sytem?

1970

What should be the amps for a MV fuses for transformer 630kVA 20(10)/0.4 kV

2038

What are the transformer losses?

1174

Why field rheostat is kept in minimum position?

1245

some basic standard questions on transformer.

1797

Is a d.c.compound motor is use as a booster? how?

2128

What are the temperature elements?

1231

How to select a contactor? How many types of contactors are available

3278

description with working of all parts of a Diesel generator???????

2481

1. what is usage for power factor in industries?? 2.why we need to monitor power factor??

8205

How out of step protection relay works?

2440

My question is whether bellow formula is correct to find bus size for 46kA for 0.5 second & what is RT in bellow formula. formula to calculate the size of busbar to withstand the thermal stresses due to currents with duration of 0.2 sec to 5 sec. Sp = RT( I x I x t) / K Where Sp – is the cross sectional area of bus bar in millimeters. I -    is the value of AC fault current. t -    is the operating time of disconnecting device in seconds. K –  is the factor depending on the material of the conductor, insulation and initial and final temperature. Value of ‘k’ for copper is 143.

1880

If any HVDC line is going with positive & negative(the negative usually have return path of current with earthing electrode). Now the question is if this HVDC earthed electrode which is using as return path and earthed any nearby 400kv or 220kv AC substation equipments. which will be the impact of this on AC substation & its equipment, how severe may be this and what should be the minimum distance require between HVDC earthed electrode and AC substation equipments? It's really an high engineering level question...Dare to answer and increase your knowledge.

1882