Motor Schematics (Large Motors above 4MW)

[Ashdgee]

Good day engineers

Can anyone please please please assist me with some wiring and control diagrams (Any starter type is fine) of large synchronous (even induction) motors that are above 4MW. Recently joined an EPCM firm doing mining and mineral processing projects and we have upcoming projects that involve addition of 22MW and 36MW ball and sag mill motors.

I just need to familiarize myself with the control and wiring schematics of these large motors (I have worked with smaller motors for water and wastewater).

If you do not mind, it might be helpful if you have any on some past projects.

My email address is ashdgee@gmail.com

 

[jraef]

The control diagram for any induction motor is no different from another; on-off via contactor, overload protection drops out the contactor. The protection scheme likely will be, because on a motor with that kind of investment, you want the best Motor Protection Relay you can find. At that size, I would even consider differential protection (look that up if you are unfamiliar). Most of the best MPRs can accommodate Differential Protection, you just need to add the extra CTs in the motor connection box.

Synchronous motors are totally different and before you embark on a control scheme for one, you need to know which type of excitation package it needs. There is no generic way to anticipate it without knowing.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[ScottyUK]

Motors in that size range might well be switched by breakers, not contactors - the control schematic may have more in common with a distribution transformer feeder of similar rating, with the obvious difference of a motor protection relay rather than a transformer relay.

 

[waross]

Bearing temperature an d vibration monitoring s well as winding temperature monitoring will have a lot in common with a similar sized alternator.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[GroovyGuy]

Howdy Ashdgee,
Scotty is correct, you will be using CBs to start (22MV-36MW) motors (and not contactors). More importantly, how will these motors be started (ie Direct-on-line, reduced voltage, ASD)?
Regards,
GG

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

 

[FacEngrPE]

The wiring diagrams are the solution, seems like a better place to start is with the requirement. This slideshow presents some of the things needing consideration when starting large motors.

https://fr.slideshare.net/DelchoPen...-motors-typical-solutions-or-new-motor-design