When performing voltage and current measurements for power testing or current signature analysis, careful attention must be given to the current probe range selector switch, if available. Many of the clamping current probes offer more than one range like 10 amps and 100 amps. Additionally, these probes are often designed and built with a burden resistor resulting in an mV output from the current probe. If the wrong position is selected on the current probe a relatively large mV output may exceed the maximum input voltage of the test device resulting in irregular or clipped current measurements and displayed signals. So remember, if you are measuring 100 amps on a 10 amp scale you might think you have a motor problem…but you probably have a meter problem.

The space between the rotor and stator of an electric motor is called the air gap. A large air gap requires high magnetizing current, hence lowering power factor and reducing the performance of the motor. To obtain good operation, the air gap should be made as small as possible. Anything that may increase the air gap, such as grinding the rotor laminations, or filing stator teeth should be avoided to prevent increased magnetizing current and lower power factor. 

To prevent damage to the insulation on the coils, the air gap should be tested periodically with the PdMA EMAX tester. The Eccentricity test is used to determine air gap anomalies and/or to trend changes in air gap by identifying and evaluating the amplitude of sidebands that develop around the Eccentricity Frequency (Fecc). Fecc = # of rotor bars x speed of the shaft.

Management and ownership should be concerned that while they may be able to replace the skills, they may not be able to replace the experience of retiring personnel. This is a trend that needs to be addressed in just about every facet of business including motor reliability and maintenance. The dwindling of those human resources who understood all the fundamentals for ensuring a motor’s efficiency and long life is a real issue. What is needed is coordination and balance of maintenance procedures and human resources in a manner designed to eliminate potential costly shortcuts that may negatively impact motor operations-and that does not change with a company’s efforts to run lean. Even with fewer resources, it can be done, but only through rethinking the entire strategic approach to motor maintenance. That means identifying potential faults with fewer people and less money without jeopardizing motor efficiency and lifespan.

 

Source: PdMA

Experienced Manual Machinist / Tool Maker – Machine Shop

Union positions up to $30 hour (Starting $23-30) are available for highly qualified machinists. Plus, great retirement and benefits plan. Frequent overtime also available.

Suggested Training/Knowledge/Experience:

• Manual machining (3 years)
• Metal work on manual engine lathes
• Mechanical repairs (welding, boring, and some fabrication)
• Read from complicated blue prints, sketches, or detailed written instructions
• Be able to machine with minimal error and hold machining tolerances within. 001
• Adhere to quality assurances procedures and processes
• Mechanical and electrical aptitude

We currently have an opening on our day shift! Overtime is dictated by customer requirements and a pre-employment drug screening with physical is required.  We are a drug free Company and we do random drug testing.

We’re looking for qualified professionals who take pride in their work, can work positively and cooperatively in a team-oriented environment, and understand that the customer’s expectations are priority 1.  Compensation is based on education and experience.  A very competitive wage is offered. 

Apply on-line with our easy application. 

Mail a resume to: 

Decatur Industrial Electric, Inc. Attn: Careers 1650 E. Garfield Ave, Decatur, IL. 62526

Decatur Industrial Electric is an Equal Opportunity Employer.  

US Military veterans are encouraged to apply!

Do you know the primary functions of lubrication?

1. Friction Control -to lubricate all true rolling contacts, balls or rollers by hydro dynamically separating moving surfaces simply put “Separating Components By Hydraulic Film”
2. Lubricate Non-Rolling, that part of the contact between the raceways and all rolling elements that are not rolling
3. Lubricate Sliding, that contact which exists between the retainer and other parts of the bearing
4. Corrosion Control, to protect the highly finished surfaces of the roller elements and rings from corrosion. Including the bearing housing(s
5. Temperature Control, provide a heat transfer medium (cooling).
6. Block Contamination, grease acts as a seal to prevent entry of contaminants