Even motor protection, why motor burn out ?
Answer Posted / atul naik
Its not 100% true. Actually Motor has been protected many
a times before it actually burns. But either we have
ignored the actual reason of tripping by resetting OL
Relay or by removing the Over Load on Motor.
Still Motor Burns. So it is observed that following reasons
are there. 1 Dips in Supply Voltage, 2 Frequent Over Loads
reduces the performance/ sensitivity of OL Relay 3 Short
Ckt Protection is Not there (ANSI 50 & 50N )4 Short Ckt
Protection is Not Fast or delayed ( to avoid Nusence
tripping in Starting )5 Impairing of an Insulation due to
entry of unwanted gases,liquids etc,Reducing the Insulation
Strength of the Motor.,6 Wornout bearings, it will not only
oppose the motion and create resistance but also it
increases the heat / temp. 7 In case of CT Operated
Relays , CTs may reduce senstivity. Now, the cumulative
effect is that Fault Clearing Time is More than the Temp
rise time due to Fault , due to which Motor insulation
fails and motor winding no longer remain healthy ie Motor
burns.
| Is This Answer Correct ? | 19 Yes | 1 No |
Post New Answer View All Answers
Write the force balance equation of ideal spring element.
what is high - pot test. what's its use?????
Why magnetic flux produces an induced current?? what is the detailed procedure ?? ans plz
what is doid
i m doing DEEE in part time,can i join regular cources in BE,,IF i join what the cources can i select like (civil,ece,IT) ,,kindly advice
Maintenance of transformer???
How is operate breaker failure scheme in substation
how to calculate maximum current
RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV is ok ,but haw to calculate the KA rating?
why does a dc machine has high efficiency while working as a generator than as a motor ..
PAC and simple Ac different
what are the dimensions for 200 kva transformer plinth (plateform),in which pcc m20 is used..
What is meant by Im=30mA@Vk/2. How to know the kee point voltage for CT design
What is bridge rectifier and explain with details
Match the following a)(X'+Y') b)X'Y' C)XY 1)NAND 2)NOR 3)Carry