Why no-load primary current is very small
as compared to full load current in transformer (as 1% of
full load current?

Answer Posted / azam

No load pr-current of a transformer is only 1-3% of FL
current because when supply applied 2 t/f it produce
alternating flux which induces emfs in primary & sec wdgs
with in the fraction of second. where as in the case of motor
starting current drawn by it is very high due 2 no presence
of back emf

Is This Answer Correct ?    3 Yes 6 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

why co incidence factor considered in transformer sizing?

1520


What are the significant parts of dc generator?

734


describe the fully control circuit diagram of ac drives

1446


I want single line diagram for AMF & DG syncronizing panel

6733


which pump used in STP

1770






working principles of cf lamp,incandescentlamp and f lamp?

1932


We have drive feeding an output contactor for a 5000 hp motor @ 5kV application. The motor FLA is 629amps x 1.25% service factor = 786.25 amps The cable that we current have in place between the drive and the output contactor is 350kcmil- MV-105 (parallel cables). Per the NEC table 310.60 (C) (69). This show the cable ampacity is at 615 amps per cable for a rating of 1230 amps. We have derated the cable for the cable tray and the multiple cables application and our calculations show that after the correction factor factor we are at 922amps. 1230 amps x .75% correction factor factor = 922.5 amps. The customer is driving us to then use another safety factor of .25% off of the already derated cable. Can you please provide a longhand calculation for your solution on this application?

1798


Apparent power is expressed as V * I(Conjugate). Why not in V * I ?

3534


How many types of probe used in cro?

772


battery capacity use of made?

2213


are there rmu for 3 transformer?

1525


What is the instrument to check the rotating diode fuse of alternator in running conditions?

2123


Explain what are inter-poles and why they are required in a dc machine.

719


WHAT IS counter flux IN CT?

1610


Please explain the following and how these are working with PLC unit 1.I/O Module 2.I/O Device 3.Adaptor Card 4.Ribbon Adaptor 5.RS 485-FC

1259