Motor starting study

[stretched2thin]

Can anyone please point me to a guide on how to perform a motor starting study? I know it involves voltage drops in cables, starting curves, etc., but I don't know anything about the details.

Websites or books would be helpful.

 

[busbar]

Starting form square one in an ANSI purview, you might obtain IEEE Std 399-1997, “Brown Book” and possibly IEEE Std 141-1993, “Red Book”. shop.ieee.org

 

[aolalde]

My recommendation for motor starting includes:
a. - Load speed-torque curve and reflected constant of inertia at the motor shaft.
b. - Motor speed- torque curve, speed-current curve and motor current-time thermal withstand.
c. - Type of start configuration. (Reduced voltage, part-winding, wye-delta, soft starter, etc).
d. - Load conditions; (uncoupled, reduced load, etc).
e. - Power supply parameters and voltage drop due to current demand at motor start.
f. - Calculation of motor starting time. Based on the speed- torque curves, system inertia and voltage-frequency applied.
g. - Analysis of the line and motor heating and current relays coordination based on starting time, motor current and heating curves.
h. - Verify allowed number of starts.

 

[jraef]

A good start for some of the necessary information can be obtained with an inexpensive program from

http://www.lmphotonics.com

called "Electrical Calculations". It calculates motor torque speed curves and load curves for typical industrial applications, allowing you to match them up with your starting method. It is $22US and worth it.

For an in-depth starting analysis, SKM software is good, but very expensive, usually out of reach of an occassional user but a usefull tool for consulting engineers. Several control manufacturers own it and will perform an analysis when you are seriously considering using their equipment.

http://www.skm.com/ns/products/tms.htm

"Venditori de oleum-vipera non vigere excordis populi"

 

[CJFlatters]

I use SKM and have Dapper and TMS etc


TTFN


_______________________________________
Regards -

Colin J Flatters
Consulting Engineer & Project Manager

 

[jbartos]

Suggestion: Visit

http:///

http://www.sumatron.com

for Power Engineering EE Helper

 

[Marke]

Hello stretched2thin

It really depends on why you are doing the motor starting study.

Incorrect motor study has two major effects:
1) excessive disturbance on the electrical supply
2) excessive wear and tear on the mechanical equipment.

You need to determine what you are trying to improve and then base your study on that. In many cases, the client is interested in a reduction in maintenance, and that can be both electrical and mechanical.

Best regards,

Mark Empson

http://www.lmphotonics.com

 

[stretched2thin]

Thanks. All responses were helpful. I think I'm going to start with the IEEE Brown Book and then move on to some of the other resources.

Thanks.

 

[jbartos]

Suggestion: Alternately, this Forum and web sites may be surfed for reasonably good results, e.g.

http://www.esmagazine.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2503,9002,00.html

http://www.esmagazine.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2503,13289,00.html

http://www.emersonmotors.com/jsp/basics/default.jsp

http://www.leeson.com/products/techref/

etc.