An industrial motor can be an expensive piece of machinery. Smart facility managers look for the best value when selecting new motors. All too often, however, the terms “value” and “price” are used interchangeably. Sure, the less expensive motor saves money in the short run and keeps you in good graces with the folks in accounting. But, it’s better to know what a motor actually costs during its 20-year or 30-year lifetime. Most people don’t.
That’s because about 95% of a motor’s lifetime operating costs are spent on electricity, which is bundled into the plant’s utility bill. The remaining 5% includes everything else – purchase price, installation, maintenance and other costs. It’s easy to know how much you’ve paid for a motor. But, in most cases, finding how much you’ve paid for the electricity it consumes in a day, a month or during its lifetime is much more difficult. Thus, the real cost of the motor, its life-cycle cost, disappears into the facility’s overall operating budget.
So, is a motor’s purchase price a small factor in overall life-cycle cost? In many cases, the answer is a resounding “yes.” To minimize life-cycle costs, it’s important to minimize energy costs. In fact, purchasing energy-saving NEMA Premium motors can avoid thousands or even tens of thousands of dollars per year in energy costs.
NEMA Premium motors: often the most cost-effective
You need to consider operating hours, electricity cost and other factors. For example, if a motor has a low duty cycle, the incremental investment for premium efficiency might not pay off. Or, it might be more cost-effective to repair a failed motor than to buy a new one.
That’s where Motor Decisions Matter (MDM) comes in. MDM (www.motorsmatter.org) is a North American public awareness campaign that can help you make cost-effective motor decisions and implement sound management strategies. MDM is sponsored by organizations that understand the long-term effects of motor decisions that industrial and commercial facilities make every day. Sponsors include electric utilities, motor manufacturers, motor sales and service providers, and government agencies. Trade associations representing manufacturers and service providers also are MDM sponsors.
Avoid crisis decisions
An effective motor management plan addresses common motor decisions before they become a crisis. By planning ahead, you can identify the most cost-effective option for each motor, basing your decision on long-term economics, not availability or first cost. Ensuring the right motor is available when you need it can help improve productivity and reduce energy costs. And because motors can last for 15 years or more, each sound decision you make today can have a positive effect on your bottom line for years.
Unfortunately, not everyone knows about motor management. MDM’s sponsors commissioned a survey of facility managers and other plant personnel during 2006. The results clearly demonstrated that overall awareness and understanding of basic motor management issues and NEMA Premium motors is relatively low.
For example, only 7% of the survey respondents understood the relationship between a motor’s operating costs and its purchase price. Nearly 60% of those surveyed didn’t have any type of standardized policy for purchasing motors and only 45% used life-cycle costing in their motor-purchasing process. And, only 37% could name at least one benefit of NEMA Premium motors.
Developing an effective motor management plan might appear to be a daunting task, but there’s plenty of help available. Your motor vendor or service provider might be able to help you map out a suitable plan. Don’t forget to check with your local electric utility for possible support. In addition, review the free resources available from the MDM Web site, the Department of Energy, MDM sponsors and other organizations. We’ll look at these resources a bit later.
For now, the individual elements that make up a motor management plan can be mixed and matched to suit your plant-specific needs and budget. Choose those that are right for you.
Survey existing motors
In many cases, the first step in developing a motor management plan is to conduct a motor survey that gives facility managers important basic information about the motor fleet: where, what and how many. Then it’s time to implement a system for cataloging the information.
If the facility has a large number of motors, it might make sense to inventory those powering the most critical applications, focusing on motors with the longest annual run times, highest failure rates and the greatest age. Additional motors can be included in the inventory over time. There are several motor inventory tools available including DOE’s Motormaster+ software (see sidebar, “Resources”).
Plan for repair versus replace
Once you know what motors are operating in your facility, it’s time to think ahead about motor failure and determine whether it’s more cost-effective to repair the motor or replace it. There are many tools available for making this cost comparison and several are listed in the Resources sidebar.
If you go with the repair option, verify that your service provider is following best-practice repair guidelines, which ensure that motor efficiency, along with other benefits, will be maintained during the repair process. The Electrical Apparatus Service Association (EASA) and the International Standards Organization (ISO) provide guidelines for best practices on their respective Web sites (see Resources).