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Anonymous Poster #1

Star-Delta Starter Tripping by Simocode

01/04/2013 11:22 PM

Dear Friends,

we have one 3 ph, 415V, 200 KW,344 FLA, 988 RPM VVFD duty ABB make motor with star-delta starter feeder with simocode pro-v protection module. current measuring module is placed at main line only. motor overload setting kept at 344 A only.

Connected load is process fan in cement industry.

All trials with Inlet damper closed to minimised load on fan.

Motor runs in no load (decoupled condition) very good, no problem in star delta conversion also. current also normal say around 70 amp.

But when coupled, motor takes almost 700 amp during star time(55 seconds timer set time) and remains continue and during delta conversion hardly reduces to 690 amp only, but at the instant of delta current motor takes almost 1200 Amp and motor trips by simocode protection. perhaps motor gains full rated speed very smoothly by almost at 45 seconds.

motor winding resistance(13.2mili ohms) and IR values(600M Ohm) already checked o.k.

so is it some thing to do with the simocode setting, we have tried with up to class-30 curve setting in simocode.

shall we try for UPPER CURRENT LIMIT SETTING 400%(in view of 1200A peak current at the time of delta conversion) with delay time of 10 seconds.

and secondly shall we use change over pause time in simocode programme for star to delta conversion.

please suggest to over come this nuisance tripping.

Regards,

V Ramchandra Rao

Electrical Engg.
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lyn
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#1

Re: Star -delta starter Tripping by Simocode

01/04/2013 11:47 PM
  1. Motor Management and Control Devices SIMOCODE pro
  2. [PDF] System Manual SIMOCODE pro 631605022000 DS 01 - Siemens
  3. [PDF] SIMOCODE pro - Siemens Industry, Inc.
  4. [PDF] SIMOCODE pro - Siemens Electric Motors
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pnaban
Guru

Join Date: Jun 2010
Location: srilanka
Posts: 2725
Good Answers: 5
#2

Re: Star -delta starter Tripping by Simocode

01/05/2013 2:49 AM

contact manufacturer or local representative

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JRaef
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United States - Member - New Member Engineering Fields - Power Engineering - New Member

Join Date: Sep 2006
Location: California, USA, where the Godless live next door to God.
Posts: 4665
Good Answers: 804
#3

Re: Star -delta starter Tripping by Simocode

01/05/2013 9:07 AM

You can look at the trip history in the Simocode to see exactly what it tripped on, it's pointless to be guessing as to why it is tripping.

The Simocode has short circuit protection that can easily misinterpret the transition current spike as a short circuit. You may only be seeing 1200A, but in theory that spike can be as high as 6000A, but for a time too short to be seen by an average meter. If that's the case, there may be nothing you can do in the Simocode to prevent this tripping.

As your acceleration time is 45 seconds in Star, then that means this is a high inertia load and was probably not a good candidate for open transition start-delta starting. Either go to closed transition, or forget star-delta and use a solid state starter.

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Ramchandrarao
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Join Date: Apr 2009
Location: At SAARC country site.
Posts: 6
#4
In reply to #3

Re: Star -delta starter Tripping by Simocode

01/05/2013 1:25 PM

Dear Mr. JRaef,

Thanks for the valuable reply please.

In my mind something like same was going on, but----

Further to add more, let me inform you that today we have tried with simocode curve class-40 and additionally we used the option of upper current limit setting to 400% for 6 seconds.

CL-40 setting as per the curve protects up to 65 seconds, so motor runs smoothly up to 55 seconds in star mode and gains full rated rpm with approx 200% of motors rated current, but again at the time of delta conversion instantly it gets trips with almost 400% load current with a display message - FAULT 48 BLOCKING.

In simocode manual no clue for this msg.

Any way one more option I would like to try, i.e. changeover pause time in simocode programming to get reduce the motor emf at the time of delta conversion followed by reduced delta current.

Awaits simocode internal programming person.

lets see-----------.

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Anonymous Poster #2
#5
In reply to #4

Re: Star -delta starter Tripping by Simocode

01/06/2013 5:33 AM

Initially posting as anonymous ...............

then reply by Ramchandrarao....
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Anonymous Poster (1); JRaef (1); lyn (1); pnaban (1); Ramchandrarao (1)

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