Single Phasing Fault in 3 - Phase Motor | Motor Single Phasing

Single phasing fault in 3 - Phase motor is considered to be the very serious fault because in running condition when single phasing occur or when one phase break or disconnected, the motor tries to rotate the load in turn it draws excessive current which results in burning of windings.
I have also showed how much current will flow when single phasing occur.
#singlephasing #singlephasingmotor #electricmotor #electricallectures

[@myasir8129]

very serious fault well explained

[@bnee4313]

does motor starter turn off if one phase is missing while in operation?

[@muhammadwaqas427]

Grateful. How can we avoid single phasing

[@ElectricityFrenzy]

You can use phase loss protection relay.

[@that1electrician]

Size your overloads properly.

[@bernardob.bacanijr9365]

What do you use in 3phase motor to avoid damaging? thank you

[@electricallectures]

Overload relay whether it is thermal or electronic but I would prefer electronics for its accuracy. OL protects the motor in event of faults

[@haxboi5492]

Use a breaker that pops all three phases instead of seperate ones

[@that1electrician]

​​​@@haxboi5492Wrong answer. Breakers are used as short-circuit protection. Single-phasing is NOT a short circuit, so chances are your motor is gonna burn up long before your breaker ever trips. Overloads are designed to catch things like single phasing. The bimetal element will heat up and trip a lever that'll drop out the auxiliary OL contact that's wired in series with your contactor coil. Size your overloads (and motor branch circuit wiring) correctly... 125% of FLA.

[@Xtreme49]

If one of the phase gets loss but the fuse to that phase is still close will backfeeding happen back through that phase. In a 3Ph 4 Wire system

[@electricallectures]

Its not that for no reason phase is lost. Without any thing open circuit from load to sorce, the phase cant be lost. In that case no current will flow in it

[@jbthegreatvlogs523]

Thanks i learn more about elec.

[@conybrown991]

Experienced this first hand 10 years ago, i was blamed of purchasing an incompitable motor by an AM who was responsible for electrical installations from MCC to motor. I knew very well the motor i chose was compitable to the system as it was a duty standby design and duty one had been working normally without a single fault for 3 months. When the standby pump manual start button was pressed, the motor started to rotate and within a mintue 10K USD was lost. PM asked the AM to check the system comprehensively and the AM replied everything was checked, nothing unusual was found, and it was my mistake leading to the loss. I was then asked to purchase another motor to correct my mistake, and within a mintue after the pump was started another 10K USD was lost. The PM then asked the motor supplier to check what happended and figured out one phase wire was not connected at all. From the very beginning to the end, the PM didn't blame me and I didn't say a single word on this, but the AM never aplogized this.

[@electricallectures]

Unfortunate but that happens in the field. Thanks for sharing your experience

[@that1electrician]

So like, you don't ohm out all your coils and do a megger test before installing a new motor? That's like rule #1 my guy. Make sure you're not about to waste your time rigging in and connecting an already-bad motor...

[@bernardob.bacanijr9365]

Can you tell me what are the problems of single phasing protection for 3 phase system can you ask for 3 to 5 problems? sir thank you

[@electricallectures]

I dont cleay understand what u want to ask

[@shivamrathi987]

overheating, insulation damage, vibration

[@jbthegreatvlogs523]

Jb the great vlogs sending you a full support

[@electricallectures]

Thanks alot

[@mohdhazhari3778]

I had problem..got voltage on all phases but no amp on Red phase..what causes the problem?

[@electricallectures]

Ur connection to the motor is open. From contactor

[@mohdhazhari3778]

@@electricallectures u mean the winding?already check the connection,all in good order..been doing continuity test..got reading on w1-v2..its not normal rigth?

[@mohdhazhari3778]

@@electricallectures im using auto trans starter..when switch on,run and star contactor energised..got amp reading on Red phase,but when main contactor energised,the amp on R are 0 amp

[@electricallectures]

If star delta starter is used tgen delra contactor j Has one phase open

[@bhupendraaditya6960]

Thank u so much sir.

[@electricallectures]

Thanks. Stay tuned and dont forget to subscribe plz

[@BaconPersuasion]

This video saved many thousands of dollars in component loss in a multi million dollar aircraft..... I hope.

[@electricallectures]

Thanks. Stay tuned and don't forget to subscribe plz

[@binonna7980]

how 173 % comes

[@SyedAlthaf-hg2kn]

One phase high amppere problem solution

[@myasir1355]

[@el-dorado4645]

how to carry test

[@electricallectures]

What type of test

[@el-dorado4645]

like Earth fault ,short circuit test how check that which phase is fault

[@electricallectures]

This can be done manually through multimeter after disconnecting the motor

[@el-dorado4645]

how we check in motor terminal box

[@electricallectures]

Best way to check it first from the contactor then come to motor terminal

[@anonymousperson2578]

Jogdish? Is that you?