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
How to calculate or formula to calculate rhe power in 2 phase system ??
is it possible to turn on the single phase star delta on delay timer using 24 v dc ?
What is meant by Load Encroachment in OHL Feeder Protection?
what will happen reduce the transformer voltage from 415v to 406v, is it save the energy,? are this methodis good to reduce the energy.?
How can we find the breaking capacity of a Load breaker switch (LBS) fed from 11 kv supply??ex:50KA, 26kA etc???detailed step vice answer pls.
Why should we hire you over the others waiting to be interview?
Where can i get practical knowledge of solar system?
what is mppt (maximum power point tracking ) and how they used in solar power generation ??? what are the main components used in mppt?????
What is highest size of HT motor like 11 kv or 33 kv,and how to make it 750 rpm.i think the size will be very big.any idea ? pl. reply..
When we use air circuit breaker, it has O/L protection ,time delay SC protection, Instataneous SC protection & ground fault protection. They all have some setting range. But what is the suitable/allowable setting for the above protection which will be safe for the equipment? For example-O/L protection setting have a range of (0.4,0.45,0.5,0.55,0.6,0.65,0.7,0.8,0.9,1.0)xIn Time delay SC protection have a range of (1.25,1.5,2,3,4,6,8,10,12)xIn Time delay setting is 0.02,0.1,0.2,0.3,0.4 Instataneous setting is fixed to 20xIn Gound fault setting is given 100A,300A,600A,900A,1200A This setting are for 2500A ACB. So what will be the basic allowable setting for the above protection? is there any formulae to calculate this<
How can we measure the residual voltage in dc machines?
What are the function of different components of servo motor?
what is charger supervision and control supervision?
what should be correct gas pressures to be a 1.5 ac unite
how to minimize earth resistance upto 2Ω, if the resistance is 6 Ω ?