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Join Date: Jan 2017
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Three-Phase Alternator

01/23/2017 7:57 AM

If prime mover rotates in reverse direction what happened to the current in the alternator

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Guru
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#1

Re: 3 phase alternator

01/23/2017 8:01 AM

The phase rotation is reversed. The current couldn’t care less which way it goes.

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#2
In reply to #1

Re: 3 phase alternator

01/23/2017 8:04 AM

hi pwslack. What happened with voltage if a motor is connected, reveresed direction also?

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#3
In reply to #2

Re: 3 phase alternator

01/23/2017 8:12 AM

Motors reverse direction.

Lamps make the room darker if you reverse them.

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#6
In reply to #3

Re: 3 phase alternator

01/23/2017 1:35 PM

Fans can suck all the air out of the room in reverse? OMG!!!

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#8
In reply to #3

Re: 3 phase alternator

01/23/2017 3:38 PM

Lamps make the room darker if you reverse them.

Which is why you never see 3 phase lamps... makes life simpler.

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#15
In reply to #8

Re: 3 phase alternator

01/24/2017 5:19 PM

Lamps normally suck the darkness out of the room. When they are full of darkness, they no longer operate. You have probably noted that burned out lamps are black inside.

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Guru

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#16
In reply to #15

Re: 3 phase alternator

01/24/2017 7:07 PM

And if you use 3 candles, light them in steps, (3 phases) they will suck the darkness out of the room and you will have an inrush of Iamps.

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#4
In reply to #2

Re: 3 phase alternator

01/23/2017 8:12 AM

If a 3-phase motor is going sdrawkcab, then swapping any two of the incoming phase conductors will remedy the deficiency.

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#5
In reply to #4

Re: 3 phase alternator

01/23/2017 8:14 AM

Got it, just like reverse contactor thing. Thank you.

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#7
In reply to #4

Re: 3 phase alternator

01/23/2017 1:36 PM

and putting two of the three phases on the same conductors results in major leakage of smoke.

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#10
In reply to #7

Re: 3 phase alternator

01/24/2017 2:53 AM

...until the circuit protective device operates to disconnect the fault, of course.

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#14
In reply to #10

Re: 3 phase alternator

01/24/2017 3:21 PM

Hopefully that has not been rebuilt by a noob, or other disqualified or unqualified person.

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#20
In reply to #14

Re: 3 phase alternator

01/25/2017 8:58 AM

#10⇑ still applies, even then.

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#21
In reply to #20

Re: 3 phase alternator

01/25/2017 9:12 AM

Yes, yes, even if the protective device is all the way to the generator output transformer breaker.

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#22
In reply to #21

Re: 3 phase alternator

01/25/2017 9:34 AM

No, No, all wrong in this instance. One can use an passive infrared sensor and when it sees the flash it can trigger the breaker to trip, and by placing smoke detectors along the single cored 3 phase cable route, upon smoke detection these may also be utilised to trip the breaker at both ends, thereby trapping the fault between breakers. It is fool proof, the fault cannot escape that cable section. Pure genius!

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#23
In reply to #22

Re: 3 phase alternator

01/25/2017 2:37 PM

That is like closing the barn door after the horsey has scared off the farmer's daughter!

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#9

Re: Three-Phase Alternator

01/24/2017 2:20 AM

Only the phase sequence will change.

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#11
In reply to #9

Re: Three-Phase Alternator

01/24/2017 4:39 AM

And that phase sequence change will play havoc with the magnetic poles, coupled to darkness, no air, and backward flowing amps, we are doomed I tell you, doomed!

NB, will my washing machine make my clothes dirtier if it turns backwards rather than in reverse?

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#12
In reply to #11

Re: Three-Phase Alternator

01/24/2017 10:09 AM

It will certainly result in an increase in local and universal entropy.

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#13

Re: Three-Phase Alternator

01/24/2017 2:25 PM

If it's connected to a jukebox playing country music, he gets out of prison, gets his dog back, gets his truck back, his mom gets unhit by a train, he sobers up and the queen of his double-wide starts liking him again.

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#17
In reply to #13

Re: Three-Phase Alternator

01/25/2017 8:39 AM

OK that is too much winning for a morning in January, cut it out.

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#18
In reply to #17

Re: Three-Phase Alternator

01/25/2017 8:46 AM

You should have read that post in the afternoon in February, and had a 'pick-you-up'

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#19
In reply to #18

Re: Three-Phase Alternator

01/25/2017 8:48 AM

February is truly one of the "dark" months. Soon the days will be noticeably longer.

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Andrew Westman (1); Anonymous Poster (3); IQ (3); James Stewart (8); JRaef (1); kvsubramanyam (1); PWSlack (3); Rixter (1); TonyS (2)

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