DID YOU EVER WORK WITH HEAVY MOTORS - AS 4160 kV 900 HP

[bobziva]

Did you ever work with heavy motors such as 4160 Volts, 900 HP. Specially what I need, are info about specification of this equipment. Also info about starters and protective relaying are welcome.

 

[GGOSS]

Hello bobziva,

Unfortunately your question does not provide sufficient information for anyone to make useful suggestions. Try adding detail about:

1. What is the driven machine ie pump, fan, mill, compressor, crucher, conveyor etc etc
2. What is the quality of supply? Solid, Weak etc etc
3. How down time critical is the plant? How significant are the down time costs/loss of production etc etc.
4. Are you on a tight budget or do you have an open cheque book?

Providing answers to the above would be a bear minimum. That together with any other relevant information you can provide will ensure you secure 'sensible' responses from the members of this forum.

Regards,
GGOSS

 

[bobziva]

Hello GGOSS,

Sorry, I didn't provide all informations:

1. Motor is provided for compressor in chemical industry
2. Reliable supply must be provided
3. Down time is critical and must be minimized
4. etc.
I need some articles or any web link describing a problems associated with heavy motor 4160 V, 900 HP appr.provided for industrial compressor.
Because I have to specify this motor one day I need any information about that.

Regards,
bobziva

 

[rbulsara]

All of GGOSS's points are valid and need to be evlauated before making final decision.

But the following general guidelines are true for your type of application:

If you can live with a reduced voltage starter (you need to determine your starting torque requriement from the data of the driven load) An autotransformer type, closed transition starters are a better choice than say wound rotor starters or any other type.

For protection relays GE, ABB and other leading electrical companies make good electronic Motor Protection relays and they have all the fearure you can think of. (Setting them correctly is a whole separate issue!!)

Insist on having RTD's (min of six) embeded in the stator windigs and separate RTD for bearings. Ths needs to be ordered when motor is orderd.

Review and coordinate your plan and details with the local utility company before procurement of anything.

If you choose to provide a differential protection all six leads need to be brought out (specify in advance as this may not be a norm for MV motors). 900 HP is a boredrline case for differential protection.

As alwyas, seek help of a good consulting engineer who has experience in this kind of work.

 

[rlpuck]

Hello bobziva, you might want to put the burden of properly sizing the motor on the compressor vendor and simply issue a minimum of specs. such as, motor enclosure type, operation voltage, bearing type (sleave or anti-friction), widing and bearing rtd, Class F insulation with class B temp rise, and what service factor you want perhaps a 1.15. I would not recommend any thing other then a standard induction motor unless you have some sort of special need. You will need to tell them your starting method, ie, across the line, or reduced voltage. Any good motor this size will have "formed" wound coils.

I would state in the specs. that the compressor vendor is to supply the motor and the motor must be capable of starting and running the compressor and operating with in the specified temperature rise. Chances are the compressor vendor has done this several times and has a preferred motor vendor. You can probably get this info from them and make sure they will not be providing some sort of junky cheap motor.