@@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.
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
@@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?
@@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
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.
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...
very serious fault well explained
does motor starter turn off if one phase is missing while in operation?
What do you use in 3phase motor to avoid damaging? thank you
Overload relay whether it is thermal or electronic but I would prefer electronics for its accuracy. OL protects the motor in event of faults
Use a breaker that pops all three phases instead of seperate ones
@@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.
Grateful. How can we avoid single phasing
You can use phase loss protection relay.
Size your overloads properly.
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
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
Thanks i learn more about elec.
Jb the great vlogs sending you a full support
Thanks alot
I had problem..got voltage on all phases but no amp on Red phase..what causes the problem?
Ur connection to the motor is open. From contactor
@@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?
@@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
If star delta starter is used tgen delra contactor j
Has one phase open
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
I dont cleay understand what u want to ask
overheating, insulation damage, vibration
Thank you sir !
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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.
Unfortunate but that happens in the field. Thanks for sharing your experience
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...
Thank u so much sir.
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how 173 % comes
This video saved many thousands of dollars in component loss in a multi million dollar aircraft..... I hope.
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how to carry test
What type of test
like Earth fault ,short circuit test how check that which phase is fault
This can be done manually through multimeter after disconnecting the motor
how we check in motor terminal box
Best way to check it first from the contactor then come to motor terminal
One phase high amppere problem solution
Jogdish? Is that you?