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Synchronous Motor Name Plate Data

07/15/2021 3:28 AM

Dears,

I find name plate of the Synchronous motor having 2 current, and 2 power value, i am unable to understand the reason for this, Any one please advice why two current and power available for this motor.

Name plate details:

voltage current Power

11000 610 10.5 MW

11000 555 9.5 MW

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#1

Re: Synchronous Motor Name Plate Data

07/15/2021 5:48 AM

<...Any one please advice...>

The motor manufacturer can advise. Telephone?

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#2

Re: Synchronous Motor Name Plate Data

07/15/2021 6:33 AM

Can you post a picture of the name plate?

Is the "power" intended to indicate: input power, or, output power? In the first case it should be approximately equal to the product of the voltage and current; in the second it should be less. Curiously (to me) it's about 50% greater in both lines you have shown.

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#3
In reply to #2

Re: Synchronous Motor Name Plate Data

07/15/2021 8:09 AM

Sir,

I am unable to take photo of the name plate.

when we start the motor 25 sec run as a induction motor, after that DC power injected to rotor to run as a synchronous motor.

The power rating one for induction motor and other one for synchronous motor is it possible?

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#4
In reply to #3

Re: Synchronous Motor Name Plate Data

07/15/2021 8:15 AM

Anything is <...possible...>. The <...we...> might be doing it incorrectly, though.

The motor manufacturer is still in the best position to advise with certainty.

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#11
In reply to #3

Re: Synchronous Motor Name Plate Data

07/16/2021 10:24 PM

Is the motor made to ANSI?

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#12
In reply to #3

Re: Synchronous Motor Name Plate Data

07/17/2021 10:08 PM

No, synchronous motors use amortisseur windings to accelerate to near synchronous speed, before field application. These windings generate significant heat, proportional to slip speed. The amortisseur windings are unlikely to be designed for any duty other than starting, maybe 10-30 seconds, typically.

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#13
In reply to #12

Re: Synchronous Motor Name Plate Data

07/28/2021 4:03 AM

Synchronous motors can be used to correct power factor from other motors in the local group by injection of DC current.

When used in this manner,it is usually run without load.

It is then called a synchronous condenser.

http://www.mytech-info.com/2015/02/how-synchronous-motor-used-for-power.html

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#15
In reply to #13

Re: Synchronous Motor Name Plate Data

07/28/2021 9:17 AM

Most synchronous motors cannot be used in this fashion. Those motors that can be used this way control the rotor magnetic field with DC current through a pair of slip rings. Most synchronous motors do not have slip rings but couple the stator to rotor fields to induce rotor current.

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#14
In reply to #12

Re: Synchronous Motor Name Plate Data

07/28/2021 4:08 AM

ICYMI:In addition to aiding the start of the motor,the amortisseur windings are mainly used to smooth out sudden transitions in load while running.

They are sometimes referred to as a damper winding.

Here is more info:

https://en.wiktionary.org/wiki/amortisseur_winding

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#5

Re: Synchronous Motor Name Plate Data

07/15/2021 8:26 AM

You really should contact the manufacturer. They are the only ones who know what that nameplate means. Anyone else can only offer a WAG what that means, regardless of their education.

My WAG is these are 50 and 60-hertz electric power draws.

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#9
In reply to #5

Re: Synchronous Motor Name Plate Data

07/15/2021 11:42 PM

that was my thought also

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#6

Re: Synchronous Motor Name Plate Data

07/15/2021 1:18 PM
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#7
In reply to #6

Re: Synchronous Motor Name Plate Data

07/15/2021 5:21 PM

It's like Deja Vu

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#8

Re: Synchronous Motor Name Plate Data

07/15/2021 7:17 PM

The data plate should also list RPM of the motor.

If it is rated for 50/60cycle it should show a rpm for each frequency.

Please give all data on the plate.

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#10

Re: Synchronous Motor Name Plate Data

07/16/2021 11:35 AM

This motor was designed with a 1.10 service factor. The basis of this service factor is usually the temperature rise on the insulation, such as Class B rise on Class F insulation.

Operation at the lower rating will provide a longer service life, but these machines are typically rated for continuous full service factor operation.

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