4160 softstarters and motors (ex-prf) 2

[bklauba]

I am trying to source two items:

- 250 HP, 4160V, 3 ph, Ex-prf motor (D1Cl2, F&G), and

- Soft starter for above (does not have to be Ex-prf).

For motors, I have found US Motors, Reliance, GE and Continental.

For Soft Starters, GE, A-B, ABB and Saftronics.

Anyone know of any others out there?

BK

 

[DickDV]

Benshaw, in Glenshaw (Pittsburgh) PA is a large supplier of MV Soft Starters.

 

[AndrewMB]

why should i use a softstarter in motors if using a frequency converter can have the same results
(how economical and why) one more new engineer or pretend to be one.

 

[bklauba]

We asked exactly the same Q when we rec'd the RFQ, but have not as of yet rec'd an answer.

Indeed, for the application involved (a conveyor) we see every reason to make it a frequency converter, and have tried to communicate that point.

As you likely know, eng-types are too often outnumbered by bureaucrats, and there are indeed consequences. (We are neither the customer or the project engineer.) We are including a letter with our bid that states that a freq drive might be a better choice, from both a control eng / functional and economic viewpoint. I just hope someone both reads it, and can analyze and act upon it. They might just award it to whomever is lowest bidder, or offers brand names that they are comfortable with. C'est la vie.

BK

 

[AndrewMB]

been finding out in some books and all i can come up with is either soft starters be used where we neen to start a motor(big)and after that no did to var the speed cos they work with a const load for a long period of time,

 

[AndrewMB]

but how is that economical? (maybe only the capital of instaling the drive?)

 

[bklauba]

By reducing the speed of the conveyor, both less waste and spillage of the conveyed product (coal) and fewer starts and stops would result. The difference in cost (or savings) either way, are miniscule compared to the long term benefits.

All of which is a moot point if the analysis is done from a short-term budgetary standpoint.

BK

 

[AndrewMB]

Bk mine is a Q also,am having the same problem let the engineers or cosumers help

 

[jraef]

MV Soft starter suggestion: If you have a good relationship with GE, ABB, Siemens, Toshiba, Saftronics, or Schneider, they all have MVRVSS starters. The "guts" (electronics) of all of them are made by Motortronics, who also sell under their own name as well.

As to VFD vs RVSS, the main reasons are economic to be sure, but not just in the initial 10:1 capital cost ratio (yes it is that much different). If you will NOT be varying the speed, the VFD will cost more to operate as well. Losses on the VFD often offset energy savings when running at speeds over 90%, especially on constant torque loads such as conveyors. If it does not need to vary, gear reduction and soft starting is much more economical and reliable.

The only times a VFD should be considered are when constantly varying speeds will improve the production or efficiency rate of a system, or where starting power is so severely limited that it must be kept at 200% FLA or lower (depending upon loading).

"Venditori de oleum-vipera non vigere excordis populi"

 

[ICSD]

Check-out Benshaw at

http://www.Benshaw.com

MV starter from 2300VAC to 15 KVAC

 

[bklauba]

Thanks, I took DickDV's suggestion, and we are in contact with the Benshaw people.

BK

 

[macmckim]

Would like to suggest another brand of MV soft starter upto 15kV - called LaserV -mfg by company in Houston called OEM. Uses different technology versus some other other brand in the market.

http://www.oilfieldelectricmarine.com/laserv.html

 

[MVRockwell]

Just a small correction, AB/Rockwell soft-starters do not have motortronic "guts", we have our own.

Generally for conveyor applications tach feedback is recommended. However soft-starting a conveyor has greater risk as it is harder to ensure consistent starting condition. You may request a motor starting study from a MV soft-starter or motor vendor to determine the worst case situation of trying to reduce voltage start a motor with a fully loaded belt (which affects the inertia and load torque profile).

The benefit of using a VFD is that becomes a none issue and you have inherent speed control during production.

Check out

http://www.ab.com/mvb

for MV soft-starters and VFD.

 

[RRaghunath]

In conveyor applications the starts are frequent and can reduce the life of motors / switchgear. If the intent is to minimise the same, use of fluid coupling that can delink the motor and brake the conveyor when ever there is a trip command to the conveyor is ideally suited.

Coneveyors are high inertia loads and VFDs are not particularly suited for the application.

 

[jraef]

MVRockwell,

"Just a small correction, AB/Rockwell soft-starters do not have motortronic "guts", we have our own."

Read the post more carefully, I never said they did. I do however appologize for leaving you off the list.

Short education on MV soft starters for everyne else.
There are really only 5 true "manufacturers" of MV soft starters available in North America. Motortronics, Allen-Bradley, Cutler Hammer, Benshaw and Solcon (from Israel). All others (including the one from OEM in Texas who uses Benshaw), are using the electronics from one of those 4, mostly Motortronics. Cutler Hammer used to brand label the Benshaw, but has since switched to their own design, leaving TECO as the only other supplier branding their design. Nobody that I know of brand labels the A-B unit, Solcon is brand labeled by Magnetek and several european names. Aucom in New Zealand supposedly has a design, but has yet to sell one.

Many of the brand label arrrangements offer good value to the end users because they can be easilly incorporated into lineups of new or existing MV switchgear and/or sold as part of a motor/controller/switchgear package where system responsibility can be beneficial. I only brought this up to point out to the OP that there is more to the picture than a single source.



"Venditori de oleum-vipera non vigere excordis populi"

 

[macmil]

since rraghunath mentioned fluid couplings, I would also mention magnetic couplings for a cushioned start and fixed speed, or adjustable speed drives for cusioned start and speed control. These components are price competitive in this horse power range at 4160V.

 

[macmckim]

jraef

Small correction about OEM in Texas - checking with OEM, was told that electronics from from Altrom - not Benshaw.
Agree with all you other comments

 

[jraef]

Huh, learned something new today...
They used to use the Benshaw starter inside of the GE Limitamp structure. looks like they went their own way too.
I assume you meant Alstom?

"Venditori de oleum-vipera non vigere excordis populi"