CATASTROPHIC Electric Motor Failure - A Winding Shorted FIRE

[kiyotewolf]

i came here cause of the pink flames..

[pinoyeh]

The FLUX CAPACITOR needs a tuning.

[dshmechanic]

Which pixel is the catastrophic failure?

[LTF85199]

@dshmechanic lolz

[Valdiralita]

240p we meet again

[davidrobert2007]

You should have cranked it up!

[Moe4023]

haha, that is not funny!!!!

[MucusFelidae]

Hey guys, that's not 240p. it's less.

How-dod-you-do-that?

[HaythamBuKhadra]

System failure !!

[TheBubbleboy35]

this motor was broken before i took it out of my wife's vibrator.

[albduke1]

On some of the motors I rewind you see melted copper holes in the stator slots ,wires melted ,holes melted you know there is big time heat when that insulation fails,like a welder.Many motors have several melted holes you grind an file slots so you can rewind.Many motors get rewound multi times.Sometimes you find dead mice,snakes,frogs,etc. Inside motors.lol

[yolichka1]

keep your experiments coming. I enjoy them :) your knowledge of motors is impressive.

[ToyoCoyote13]

51 people wanted to see a motor go boom.

[aptsys]

Why so many dislikes??

[NitsanPictures]

@aptsys because this is not catastrophic is it? just a spam name for views.

[melbose]

Ooh that looks like an old banger almost looks like a slip ring motor from that view

[enproceso100]

jaja, se les tosto...

[miro0458]

wow where was this?

[RReaper100]

Catastrophic , so so Catastrophic

[fivepoint56tothehead]

have you seen a 4500 hp Reliance motor run on a test panel for only 4160 volts? that fucken test panel about exploded. funny shit when you got outdated equipment in an electric motor shop HAHA

[vexedrex555]

ha ha ha very funny. morons

[hondagoal]

@kopjesenseo You didn't see the smoke?

[LTF85199]

why does a motor burn under stress?, not when you give it over design voltage, i am talking if a motor is strained why does it burn. For example, In you car the side window, you restrain it from rising while the button is depressed and caused for the motor to burn out why?

[r83rob]

Under too much stress, if a motor cannot turn freely and thus, the winding gets overloaded and can then kick up higher amperage than its rated for and heat up and then burn. The motor I videoed here was already shorted out with a bad winding, so feeding it normal power resulted in some explosivety and fireworks. FUN!

[LTF85199]

Excellent that is what i was looking for, but that is because of the brushed motor technology right? when it is stuck at one polarity right, instead of alternating? Does this also happen in brush less motor? do you know? anyone else have anything to add or clarify?

[TehMG]

Yes, this can happen with any type of motor, brushed or brushless, DC or AC.

For AC induction motors, you can think of the rotor as being similar to the secondary winding of a transformer. Preventing the rotor from turning freely is to a motor what overloading the secondary winding is to a transformer.

That is why thermal and/or overcurrent protection is CRITICAL especially on larger motors. Large motors (above 1HP) can burn up in literally seconds in a locked rotor condition w/o protection.

[LTF85199]

Thanks TehMG for the supplemental information. I have a quick clarification for you on DC motors? does the coils get overheated because the the shaft/coil system in stuck on a certain polarity? instead of cutting on and off while alternating polarity?

[TehMG]

Something like that, yeah. The normal rotation and commutation of the windings creates a changing magnetic field and back EMF. When stalled, the winding sees nothing but DC, at which point it becomes little more than a heating element. Similar destruction will happen if you put DC into a transformer.

[waswestkan]

@TehMG The windings of a stalled AC motor will see AC, not DC. but still AC Yes they will draw more current than they would under normal operation conditions. Simply applying DC to transformer winding doesn't mean destruction. The DC power source fist has to have enough voltage to overcome the winding's DC resistance & the DC power source has to be able to deliver enough current to create heat

[EETechs]

@LTF85199 AC Induction motors have been brushless since 1888 when Tesla invented them....

[Nivicoman]

@LTF85199 It draws more current trying to keep up it's speed and the current is what heats the coils to the point of combustion.

[bodyheat69]

@LTF85199 Depending on the type of motor it can use anywhere from 2-10 times it's normal power to move from a complete stop. Which would normally only happen for a very short time when you turn the motor on, but you overload the motor or cause it to stall it will draw this unexpected current for too long and burn.

[ropeyarn]

@LTF85199 An electric motor at speed generates a counter electromotive force CEMF that limits the maximum current through the windings. If the motor is run at too high a voltage or at reduced RPM by overloading then the current through the windings is greatly increased by reduced CEMF. Increased current means increased heat. Increased heat or just age will break down the thin lacquer coating on the windings causing the short. Same thing that r83rob said only in a Tom Clancy kind of way.

[LTF85199]

@ropeyarn I think from all the explanations i have gotten so far, yours was the most sensible one.. I never knew about this CEMF phenomenon.. makes perfect sense now.. same way they generate electricity with generators huh.. thank you sir.

[ropeyarn]

@ropeyarn Let me elaborate. Motors and generators are basically the same. They convert electricity to motion or they will convert motion into electricity. They do both at the same time. They do it in opposite directions.

[YummyMercury]

@ropeyarn Not all motors can be used as generators, and not all generators can be used as motors.

[foiwater]

@YummyMercury All motor's generate

[foiwater]

@LTF85199 It's easy to explain with very basic electric theory.

The motor will draw locked rotor current when it starts up, or if prevented from rotating when rated voltage is applied.

The current it draws is determined by I = V/R, when the motor is in motion however a counter emf is developed and opposes the source voltage, so the motor armature see;s less current, therefore less heat.

Essentially, the motor draws maximum current when the motor is not turning, because of no induced CEMF.

[LTF85199]

@foiwater thanks bud, someone else also explained the same thing to me.. very interesting phenomenon..

[shoprat17]

@LTF85199 more time to have windings connected to the power though the brush/commutator assembly and the windings are being hit with an amperage that they weren't designed to handle for that long of a time

[SpiritsoftheWolf]

well, look like you going to have to manual start it now, and it can turn in either directions

[charliekv]

sweet!