July 21, 2005
Motor Testing Tip
A single test using Motor Circuit Analysis (MCA) instruments that utilize a low voltage, sinusoidal output allow the user to detect developing winding shorts within a 3-phase AC induction motor. Measurements of phase angle (Fi) and current frequency response (I/F) will detect developing turn-to-turn, coil-to-coil, and phase-to-phase shorts without the need for previous test data or temperature correction of the measurement values. Moreover, for a motor application using a VFD the measurement can be made with the drive connected, unless an insulation to ground measurement is being made.
Tip provided by ALL TEST Pro
http://www.alltestpro.com
800-952-8776
July 21, 2005
Maintenance Tip
Building Bills of Material (BOM’s) for equipment is labor intensive. Many sites try to do it with internal resources “part-time”. This is inefficient, and the work almost never gets completed. It makes sense to hire outside help for this, as they are faster and often cheaper in the end. And, you get the BOM’s done so people can find parts!
Tip provided by Dave Krings, CMRP
Author - 5 Pillars: Maintenance & Reliability Professional review course on CD
MasteringMaintenance.com
July 21, 2005
Controlling Fan Vibration with Active Balancing to Solve Series Reliability and Maintenance Problems
A Sponsored White Paper by Andrew J. Winzenz, LORD Corporation
Ever since centrifugal fans have been manufactured they have been subject to vibration related problems. These problems range from simple unbalance conditions caused by mass variations on the fan rotor to much more complex issues related to shaft alignment, bearing fatigue, or resonance issues. In many cases excessive vibration levels in fans lead to unplanned forced outages to perform maintenance. While these outages are necessary to maintain safe operation of fans, they typically are costly both from a maintenance and lost production standpoint.
This paper will discuss common vibration problems experienced on large centrifugal fans that lead to forced outages and unscheduled maintenance. This paper describes the use of an Active Fan Balancing System used to control unbalance related vibration levels in fans. The paper will also detail several active balancing installations and describe the benefits these users have experienced.
July 21, 2005
Lubrication Tip
In lubricating an electric motor bearing, long grease purge pipes create backpressure, which increases the chance of grease being forced into windings or excess grease remaining in the bearing. Therefore, drain pipes should be as short as possible and not have any turns if possible.
Submitted to Ludeca for Reliabilityweb.com by Garry Villamil of TRILUX ELECTRONICS & LUMINAIRES, INC.
LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
July 21, 2005
Inventory and Purchasing Maintenance Tip
Inventory and Purchasing Maintenance Tips to
Enhance Maintenance Planning and Scheduling
(Tip 6 of 6 in a series) Archived at
http://maintenancetalk.com/blog.php/tipsblog
CMMS/ EAM Usage and Integration
When the maintenance management system (CMMS/EAM) is properly utilized, the maintenance planning will work extensively with the inventory and purchasing module of the system. This is due to the fact that the plainer will be required to:
• Check on the availability of spare parts
• Check on the location of spare parts
• Reserve spare parts for work being planner
• Initiate a purchase requisition for spare parts
• Initiate a purchase order to purchase spare parts (in some plants)
• Check on pricing for the spare parts requested
• Check on the expected delivery date
• Receive spare parts
• Issue spare parts to the work order
• Return spare parts not used to inventory
While this list is not all inclusive, it still highlights the high level of interaction the maintenance planner must have with the inventory and purchasing information, if they are to be successful in planning maintenance work.
What are the consequences when the maintenance organization uses a CMMS/ EAM system, yet the inventory and purchasing department utilizes another system? If this is the case, it usually follows one of these scenarios:
• The two systems are operated independently
• The two systems are partially interfaced
• An attempt is made at integrated the two different systems
If the two systems are operated independently, the information in the two systems is never in full synchronization. The planner will be force to operate two systems, constantly referring to the inventory and purchasing system when planning maintenance work to insure part availability.
If the two systems are partially interfaced, the planner will have access to some of the inventory and purchasing information, but not always in a real time mode. In other words, files are passed between the systems, but it is usually in a batch mode. This delay will still have an impact on the planer’s ability to plan work in a timely manner.
If an attempt is made to integrate the two systems, it is usually expensive. The Information Systems department must constantly upgrade both systems. When this occurs, the interface usually needs to be rewritten. This is costly and time consuming.
After considering the alternatives, it is usually best for maintenance and inventory and purchasing to use the same computerized system. While each department will probably have to concede some small amount of functionality, the benefits of utilizing a fully integrated system will out weigh the functionality loss.
Tip provided by Terry Wireman
GenesisSolutions
http://www.GenesisSolutions.com
Tel: (203) 431-0281
July 14, 2005
CMMS/EAM Functional Implementation Startup/Re-Start by Christopher N. Winston
CMMS-2005 Learning Zone Session
Computerized Maintenance Management Summit
July 26-29, 2005
Indianapolis Indiana
For many years now, CMMS/EAM implementations have often been at facilities that already have a computerized system in place. That system may have fallen into a limited use mode as resources are further and further constrained based on economic climate and other factors. We will also cover how re-implementations can occur without changing the system you have in place. The focus here will be on what to evaluate first, and additional tools to assist in the effort.
Join Christopher plus more than 35 other presenters, workshop leaders and learning labs directors at CMMS-2005.
To learn more please call toll free 888-575-1245 or…
July 14, 2005
Pulse – Pulse EAR: A Predictive Technology
An iPresentation Tutorial by Kevin Deverell, RCM Technology, Baker Instrument Company
Using the Pulse-to-Pulse Error Area Ratio (PPEAR) enables the surge test to become more than just a go/no go test for motor testing and predictive maintenance professionals. This patented calculation enables the surge test to become a true predictive maintenance test.
This 7 minute iPresentation will demonstrate the highly sensitive capabilities of the PPEAR.
Windows or REAL Media Player required for narration playback.
July 14, 2005
Take your Predictive Maintenance program to the next level
PdM-2005
The Predictive Maintenance Technology Conference
September 19-22, 2005
Atlanta Georgia
Please join predictive maintenance specialists who lead workshops, share case studies, demonstrate the latest techniques and new technologies for machinery condition monitoring for 4 days of knowledge sharing at PdM-2005.
This conference designed for technology users and included both basic and advanced topics.
PdM-2005 will focus on:
• Vibration Analysis
• Airborne Ultrasound
• Infrared Imaging
• Motor Testing
• Oil and Wear Particle Analysis
• Other condition monitoring technologies
All PdM - All the Time!
To learn more, please call toll free (888) 575-1245 or…
July 14, 2005
Belt Tip
For future reference, write the sizes & types of belts used in your equipment at a safe but noticeable area of the belt cover/guard of the machine.
Use a Reflectorized Arrow Sticker (yellow) for rotation direction specially on pulleys without direction indicators.
Tip provided by Gary Villamil to LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
Watch LUDECA’s Pulley Alignment Demo Video
July 14, 2005
Motor Testing Tip
Voltage and current readings can be used to provide some value as to the condition of your electric motor.
Voltage readings should be measured from phase to phase, such that you measure phase A to B, then phase A to C, then phase B to C. The primary reason is that different types of transformers will provide different phase to ground values that are not as effective in determining supply condition. The values will provide over/under voltage condition as well as voltage unbalance condition. The present limits are that the over/under voltage condition must not be more than 10% from the nameplate voltage, with the recommendation, for energy and reliability purposes, not to exceed 5% from nameplate. Voltage unbalance is the % unbalance from the average to largest difference from average voltage. This value should be less than 5% with a recommended limit being 2% and a de-rating factor provided for unbalances greater than 2%. For instance, a voltage unbalance of 5% requires a derating of the motor of 25% (ie: a 10 hp motor would be rated as 7.5%) to compensate for additional heating.
Current readings provide an indication of percentage of load, when measured above 50% of nameplate current. Current unbalance is a normal course of operation in motor circuits (exception: power factor correction will cause balanced current) that results from phase circuit: Impedance; Power factor; Loading; Voltage unbalance; and, Possible motor faults. Loading using current and voltage can be estimated:
Load = (I/Ir) x (V/Vr) x 100%
Where I is the RMS average current,
Ir is nameplate current,
V is RMS average voltage and
Vr is nameplate voltage.
RMS current readings, by themselves, can only provide an indicator as to potential condition, but should not be counted as a pass/fail indicator by itself, due to the number of conditions that contribute to current unbalance. For instance, a small motor drawing 10.1, 7.1 and 9.9 amps would have an unbalance of 22%, whereas a motor with a current draw of 100, 87, 97 amps would have an unbalance of 8%. In this example, the first motor was a 10 horsepower motor in good condition and the second motor was a 150 horsepower motor with a developing problem.
Understanding the abilities and limitations of the tools that you have available will assist you in making the right call to correct an existing or impending problem. When using voltage and current tests only, you have some limited capabilities. Utilization of other tools, such as power analysis, electrical signature analysis or motor circuit analysis techniques can be used to verify the actual condition of the system.
Tip provided by Howard W Penrose, Ph.D.
T-Solutions, Inc.
http://www.tsoln-inc.com
Phone/Fax: 860 577-8537
Read the Penrose Lecture Series MotorBlog at MaintenanceTalk.com
