Answer / 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.

Answer / amaravathi

fuse rating will be calculated by following formula.
125% of rated current.but we can use nearest value of fuse rating value.

Answer / devamanohar

The MCB rating shall be more than the fuse rating if it is
used for the service to switch off & on while the circuit
is in service.The fuse rating shall be 200% of the rated
curent normally as it is used for short circuit
protection.If the MCB is stay put type(No operation while
in service) it can be selected for rated current or 1.2
times of rated current value.

Answer / shaik

depending on the full load capacity ratings is calculated.
It is not necessary to connect MCB and fuse both,one is
enough.if u want to connect both then first fuse the MCB

Answer / mahesh s.chorghe

MCB RATING SHOULD BE 2.5 TIMES OF LOAD CURRENT AND FUSE
RATING GRETER THAN (1.5 TIMES)MCB

Answer / moideen.t.y

Fuse size can be calculated by this formula, 225% of full
load current.
locked rotor amps is the 500% of full load current.

how ups works ? various parts of ups and working principle

0 Answers   Serco,

WHY THE TRANSFORMER VALUE MEASURES IN KVA INSTEAD OF KW.

4 Answers  

why mostly conductor made by 7 nos wire?

1 Answers  

according to ohms law ,the voltage increases then current is what happened?

4 Answers   NTPC,

how to minimize earth resistance upto 2Ω, if the resistance is 6 Ω ?

0 Answers  

Upto what extend the powerfactor of a supply system can be improved to be cost effective?

1 Answers  

what is the diffference between 3 point and 4 point starter ?

3 Answers  

we often use the word HT (high tension) line.or we say HT switch gear, whats does HT basically mean. is it different from high voltage.

2 Answers  

In an ACB shunt trip coil and undervoltage coil operated normally( breaker open and charged). But closing coil not operating untill manually discharge and recharging. Any help.

0 Answers   PPIL,

why shoud in High tension cable( above11KV etc.,)a semiconducting material coating will be there on insulation?

1 Answers  

please, Send me last technical test question paper in my email id..

0 Answers  

hii this is ranjith from hyd... i want to know what type of questions they ask in interview...and hw the interview will go..? what subjects thay ask specially for electrical engg students?

0 Answers