In a Circuit how the MCB and Fuse ratings are calculated.
And shall the fuse follws the MCB or it is otherwise?
Answer Posted / sanjay kumar
FUSE RATING CAN BE CALCULATED AS FOLLOWS:
SAY A MOTOR FULL LOAD CURRENT RATING IS 30A,TAKE FUSE OF
RATING 2.5TIMES OF FLC. SO FUSE RATING WILL BE 80A.IF IN
CASE THIS RATING FUSE IS NOT AVAILABLE, WE CAN GO FOR NEXT
HIGHER LEVEL. BUT IF NEXT HIGHER LEVEL FUSE IS SO HIGH THAT
IT CANT BE TAKE THEN GO FOR SOMEWHAT LOWER LEVEL. THIS IS
BASED ON MY EXPERIENCE IN THE INDUSTRY.
SECOND PAART IS FOR MCB:
MCB SELECTION SHOULD BE SOMEWHAT HIGHER THAN FUSE RATING.
| Is This Answer Correct ? | 5 Yes | 4 No |
Post New Answer View All Answers
What is phase cross over frequency?
what are inductive and capacitive voltage transformers.what are their applications
DG SET BLOCK DIGRAM
Define Electrical Insulation and examples of Solid,Liquid and Gaseous insulating materials?
how to calculate transformer load?
How many types of electrical earthing are there?
What is Auto Mains Failure Panel & Auto Synchronizing Panel
Give idea about General Engineering. From which book i can study this topic. Pl. reply me via email. My email is ravi@bhelhwr.co.in, also give the name of book/website, from where i can prepare it.
Saving in copper achieved by converting a 2 winding transformer in to an auto transformer is determined by A voltage transformation ratio B load on secondary C quality of core material D size of transformer core
Can u explain : what is supply for train (whether a,c or d.c ).I know that supply is 25000v a.c .But there is rumour that supply is D.C. And also explain how lights and fans inside the trains are working ,and what type of motors are used in trains whether D.C motors or induction motors .If d.c motor, how it gets supply.If traction motors are used then what are traction motors and its functions and how it differs from other motors and also explain about locomotive . y d.c series motor in train.train wheels r driven by D.C shunt motor ,at what voltage,and at what speed. please reply..............
What is the tests required for a 132 kV, 400 kV , 765 kV for a Circuit Breaker and Power Transformer before commissioning ?
harmonics filter
what is static frequency converter?what is the function...of sfc...?
If the rated speed of a d.c. Shunt motor is1440 r.p.m, which method of speed control would you suggested to obtain a speed of 1500 r.p.m?
IF % IMPEDANCE OF A TRANSFORMER IS INCREASED FROM 5.8% TO 8% HOW MUCH THE EFFICIENCY OF THE TRANSFORMER WILL COME DOWN?