Ability to compare cost of Electric Motors

[Paladin1]

Good afternoon.

I am in the process of comparing two motors and the running cost of these units over a period of time. Please advise what information I should use and how I should perform this action. I need more than just efficiency savings between two units.

I also want to know what other formulas you use in determining with motor to use.

Thanks

ScottC

 

[electricpete]

Tough question. In the ideal world you would like to have some idea of the expected ongoing maintenance costs and reliability. It can be tough to get that info.

One approach is look at OEM manual and see if any special maintenance is required. Easy to do but I don't put a lot of faith in it. OEM's differ on their recommendations but most folks end up treating all their motors the same.

There are various features that may help reliability depending on the application. Maybe you can compare bearing sizes and styles and and check whether you think they are appropriate for the expected loading. Compare the lubrication methods. If both greased, flow-through greasing is usually better.

For outdoor motors consider the suitable degree of ingress protection. I happen to like VPI motors for any outdoor application. Maybe you have some other measn of assessing the insulation from these OEM's.

You have already mentioned efficiency. Obviously initial cost.

Maybe you could tell us a little bit more about the application and the motors you are looking at.

 

[Paladin1]

What about the cost of the motor with regards to Amp pull, power factor and kw/hour cost?

How can I use this information to check savings.

Thanks

ScottC

 

[electricpete]

Lower power factor causes increased losses in distribution equipment (utility and customer equipment). The utility may or may not charge you... depends on rate structure.

I assume that KW associated with both motors is the same other than lost KW associated with efficiency/inefficiency. Usually the mechanical load determines the shaft KW unless there is some difference in speed.

 

[philtext]

Their is a motor efficiency software that your might find useful called motor master. It is also free of charge but you do need to register.
link to registration form

http://mm3.energy.wsu.edu/mmplus/mmdownload/register.cfm