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starter for slip ring motor of 4000kw


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#1 nawinlal

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Posted 15 September 2005 - 04:40 PM

I want to know that if I have a Motor of 3600 KW with starting with cutting of resiistance can I use the same with new motor of 4000KW .
Also what starter needs to be purchased for new Motor . The supplier is offering a starter with liquid saline water.
What kind of enclosure we should have for new motor where dust is quite heavy.

#2 jraef

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Posted 16 September 2005 - 05:39 AM

Only your starter manufacturer can answer that question. In medium voltage equipment, most everything is custom built, but the components have maximum ratings. If you can describe the components in detail maybe we can help.

Liquid Resistance starters offer smooth starting of Wound Rotor Motors, but you must consider the long term problems with maintenance and familiartity by those who will need to work on it in the future. This is a very old technology and there are fewer and fewer people who understand it every year. You may want to consider a solid state starter for that motor, depending onthe application. If you describe your application in more detail maybe we can help.

For enclosure ratings, IP54 would provide complete dust protection and splashing water protection, but will be probably the most expensive enclosure rating in that size motor frame. IP44 would be less expensive if you can find it, but that only protects against particles up to 1 mm in size.
"He's not dead, he's just pinin' for the fjords!"

#3 Guest__*

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Posted 21 September 2005 - 03:20 PM

Hi
On the subject of liquid rotor starters, not everything is as gloomy as Jraef has painted it. These starters are currently being manufactured widely in Europe, Australia, South Africa, India & China to name but a few.

If you can provide details of the driven machine, Rotor Volts & Amps, starting duty and eventual site; perhaps I can point you in the right direction.
Regards
Fintan Lawlor;d;

#4 GGOSS

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Posted 23 September 2005 - 04:43 AM

Liquid Resistance Starters may be considered to be old technology in today's world however they are still commonly used and provide excellent performance, particularly when they have been designed/engineered to suit the connected motor/load combination and operational duty cycle.

As far as maintenance goes, it's generally pretty straight forward and the people doing the work don't have to posess any special skills ie other than to be liscenced to work on MV equipment.

The technology is very simple, and can easilly understood by those who exhibit even the slightest interest. I'm not so sure the same can be said for MV Soft Starter and Drive products. I guess this coming from someone who has spent the last 23 years in the soft starter world is a big wrap for liquid starting technology.

Regards,
GGOSS

#5 bob

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Posted 23 September 2005 - 05:12 AM

Hi,

On a reliability point of view, liquid starter has proved itself to be very reliable. There is little point in installing an expensive item of electronic equipment to save potentially considerable amounts of money if the device is unreliable to the point that vital processes are constantly interrupted.A particular advantage of the use of the optimising soft starter is its impact on the maintenance requirements of associated electro-mechanical equipment. Optimising lowers the surface temperature of the motor by reducing the losses within the motor.
Electronic controllers for most fixed-speed applications are opening new ways of increasing the efficient operation of induction motors, as well as offering significant benefits in control. Intending users need to ensure themselves of the quality and performance of any products they expect to fit and this can be reasonably expected if compliance with the appropriate standards is demanded.

Bob

#6 jraef

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Posted 23 September 2005 - 05:58 PM

I don't question the validity of the technology, in fact I think WR motors are fantastic designs (I call them the "perfect" induction motor) and LR starters are a great way to control them. My issue was with installing something that is a dying technology, which is what I felt was the case with LR starters. I guess it is a matter of perception based on what is available in your area.

Here in the US there is only one remaining supplier of Liquid Resistance starters that anyone has ever even heard of, and they are now almost defunct, survivng on upgrades or repairs to their previously installed systems, and Slip Recovery systems to save energy on WR motors as far as I know. I visited them 10 years ago and they were down to less than a dozen employees. They told me they had not sold a LR starter for a new application in over 5 years at that time.

I come across LR starters once or twice a year, and every time I do, the user has little or no knowledge about what they are or how to use and maintain them. I am usually called in to help them replace the LR starters with soft starters. Most users I have met who had one thought it was a relic of a bygone day, unique to their plant. In several cases, I have been the only person they have met who even knew LR starters existed anywhere else! Apparently that is the case only here in the US though, so... never mind.
"He's not dead, he's just pinin' for the fjords!"

#7 Guest__*

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Posted 17 October 2005 - 05:26 AM

Liquid Starters are used more than people think.
You can find info. on these from a UK company @ www.oipengineering.co.uk

#8 jimjiang12

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Posted 24 May 2007 - 12:57 PM

QUOTE(jraef @ Sep 24 2005, 01:58 AM) View Post

I don't question the validity of the technology, in fact I think WR motors are fantastic designs (I call them the "perfect" induction motor) and LR starters are a great way to control them. My issue was with installing something that is a dying technology, which is what I felt was the case with LR starters. I guess it is a matter of perception based on what is available in your area.
Here in the US there is only one remaining supplier of Liquid Resistance starters that anyone has ever even heard of, and they are now almost defunct, survivng on upgrades or repairs to their previously installed systems, and Slip Recovery systems to save energy on WR motors as far as I know. I visited them 10 years ago and they were down to less than a dozen employees. They told me they had not sold a LR starter for a new application in over 5 years at that time.
I come across LR starters once or twice a year, and every time I do, the user has little or no knowledge about what they are or how to use and maintain them. I am usually called in to help them replace the LR starters with soft starters. Most users I have met who had one thought it was a relic of a bygone day, unique to their plant. In several cases, I have been the only person they have met who even knew LR starters existed anywhere else! Apparently that is the case only here in the US though, so... never mind.

Actually i agree with you to some extent, but LR starters enjoy good markets in China,India, and some other
developing countries based on the good performance and competitive price. I am from China . Thanks for your ideas to share with us. www.ssechina.com




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