June 23, 2005
The Mikron Infrared “Name the Camera” Contest!
Our friends at Mikron Infrared have recently launched its newest line of high-performance, hand-held thermal imaging cameras and are now soliciting input on a product name that will truly reflect the superior performance of this new product line. The lucky winner will receive the M7800 model camera and a voucher for a FREE Level 1 or Level 2 ASNT training course through Snell Infrared.
June 23, 2005
Motor Testing Tip
Rotor bar issues can and do occur in electric motors on occasion. Normally the issue relates to mis-application or improper operation of the electrical machine with rare instances of motor manufacturing defects. There are three types of rotor bar types: Cast aluminum-alloy; Cast copper-alloy; and, Copper-alloy bars. The variety of rotor bar shapes depend upon the application and design considerations for the motor, itself.
All rotor bars can fail due to extreme overloads, under voltage or too-frequent starts. The most common cause is frequent starting which causes extremely high electro-mechanical stresses. The heating and cooling causes thermal stress, the acceleration and deceleration causes inertia fractures and the magnetic fields cause mechanical stress. These stresses will eventually cause the rotor material to fracture or break. In addition, the expansion and contraction of materials can also cause looseness in the rotor slots resulting in noisy starting. Motors have number of start limits partly due to this situation.
Cast rotors have casting voids as a normal result of manufacturing. All cast rotors have some level of casting voids. (Note: The copper industry has announced that cast copper alloy rotors have fewer casting voids than aluminum alloy.) This condition has received a great amount of attention over the past several years as newer technologies are sensitive enough to identify casting voids easily. Only a small percentage of cast rotors are affected by this condition and dynamic balancing takes care of the primary concern of vibration. In severe cases, the casting void(s) may restrict or block current flow through rotor bars acting as a broken rotor bar. These are manufacturing defects that may, or may not, be honored by the manufacturer, depending on if the motor meets the nameplate of the motor.
Copper alloy rotor bars tend to break where the rotor bar exits the rotor laminations or at the joint between the rotor bars and shorting ring. These can occur due to mis-operation of the motor, such as too many starts or excessive loading and unloading, or due to poor braizing or welding of the bars.
The effect of a broken rotor bar is a reduction of torque and, in severe conditions, torsional pulses and vibration. Eventually, some broken bars may lift and damage the motor winding. However, the time from fault detection to failure can be a considerable amount of time. The detection of a broken rotor bar due to operation, as opposed to a casting void, should prompt a review of the operating conditions of the application.
Tip provided by Howard W Penrose, Ph.D.
T-Solutions, Inc.
http://www.tsoln-inc.com
Phone: 860 577-8537
June 23, 2005
5th EPRI Conference on International Maintenance - Hosted by PSE&G
August 8 - 10, 2005
Jersey City, NJ, USA
The electricity generation industry is continuing the rapid changes of the last five or more years from a stable, predictable past, to a future of competition, changing ownership, and dynamic new business goals. Adding to this new challenge, we are faced with the loss of long-term employees along with their knowledge. Many companies have mortgaged their human assets hoping to succeed in bridging the gap in knowledge and training without having developed a contingency plan.
The Electric Power Research Institute (EPRI) has structured this conference to provide some of the latest work being accomplished in the area of business evolutionary ideas, technology updates to forge ahead with more effective and efficient methods of completing maintenance work, as well as the ability to more accurately project what work has to be accomplished and when. This conference is structured for both the tactical maintenance needs as well as strategic ideas for focusing the future changes to be more successful.
June 23, 2005
Maintenance Tip
Easy Removal of Damaged Phillips-head Screws
Cross-head, or Phillips screws have a plus-shaped slot in the head and are driven by a cross-head screwdriver, designed originally in the 1930’s for use with mechanical screwing machines. They were intentionally made so the driver would ride out, or cam out, at a certain force to prevent over-tightening. After a piece of equipment has been disassembled and rebuilt numerous times, the Phillips head drive wears out in the screw head “by design.” When removal is required but the driver continues to ride out of the slot, place a small amount of lapping compound in the +-shaped slot of the screw head and proceed with removal, (always replacing the stripped screw with a new one.)
This method works like magic on all sizes of Phillips head screws and can save a lot of needless frustration. Not earth shattering technology, but a pretty neat trick.
Submitted to Ludeca for Reliabilityweb by Thomas Keefer of Tennessee Valley Authority.
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
More Case Histories and Articles by Ludeca
June 23, 2005
Inventory and Purchasing Maintenance Tip
Inventory and Purchasing Maintenance Tips to
Enhance Maintenance Planning and Scheduling
(Tip 4 of 6 in a series) Archived at
http://maintenancetalk.com/blog.php/tipsblog
Internal storage arrangements – Row, Shelf, and Bin locations
Internal storage arrangements for maintenance spare pasts are required if the parts are going to be easily found when they are needed. The key identifiers for a location would include:
• Storeroom – (If a multiple storeroom location)
• Row – The storage row location
• Shelf – The shelf level where the item is stored
• Bin – The exact bin location where the part is located.
In some storerooms, cabinets are used for storing smaller spare parts. In this instance, the identifiers might be somewhat different. A sample might be:
• Storeroom – (If a multiple storeroom location)
• General Location – The area of the storeroom the cabinet is located
• Cabinet Number – The number for the cabinet
• Drawer – The drawer where the item is stored
• Space – The exact location in the drawer where the part is located.
Why is this organization and information so vital to an effective maintenance planning and scheduling initiative? Consider the impact missing or hard to locate spare parts has on maintenance labor productivity. How often are maintenance technicians:
• Looking for spare parts in the storeroom?
• Looking for parts in remote storage locations?
• Checking the receiving dock to see if someone forgot to put up spare parts
• Scavenging spare parts from older equipment?
• Fabricating/ repair old parts, since the new one can’t be found?
These delays can only be eliminated if spare parts are properly received and then taken to properly identified storage locations. Unless this process is followed, there will always be lost productivity on the part of the maintenance technicians, but more importantly, unnecessary equipment downtime and lost profits.
Tip provided by Terry Wireman
GenesisSolutions
http://www.GenesisSolutions.com
Tel: (203) 431-0281
June 16, 2005
Managing and Executing Maintenance Training with the CMMS or EAM by Ricky Smith
CMMS-2005 Learning Zone Session
Computerized Maintenance Management Summit
July 26-29, 2005
Indianapolis Indiana
The CMMS or EAM is a powerful tool that when used properly can provide unbelievable results but where many companies do not know is that this tool can be used to assist in the management and execution of skills and regulatory training. In this session you will be provided the tools necessary to implement a process to manage and execute all types of training by utilizing your CMMS or EAM. Lessons Learned will be discussed as to what works and what does not work in this process. In this exciting program you will be provided with examples to take home. Plan to attend and add your experiences to this program.
Join Ricky 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…
June 16, 2005
Airborne Ultrasound Tip
When scanning for compressed air leaks and a leak seems to be coming from a blank wall, remember the laws of reflection “angle of incidence, equals the angle of reflection”. Place your back against the wall and scan left to right from ceiling to the floor to locate the source of reflection.
Tip provided by Jim Hall
Training Manager
Ultra-Sound Technologies
(770) 517-8747
June 16, 2005
Get Uptime Magazine - No Cost - No Kidding
World Class Maintenance demands that 50%-65% of the total maintenance budget be related to condition directed tasks. Uptime Magazine has been created to serve the people who use condition monitoring and predictive maintenance systems, much like P/PM Magazine did throughout the 1990’s.
There are several excellent publications that deal with reliability centered maintenance and other management issues but none provide much information for the Predictive Maintenance Professional who actually uses Predictive technologies such as:
Vibration Analysis
Airborne Ultrasound
Infrared Thermal Imaging
Motor Testing
Oil Analysis
Precision Maintenance
-Alignment
-Balancing
-Leak Detection
-Lubrication
Print (USA & Canada) Subscriptions and Digital (Everywhere) Subscriptions are available at no cost by request.
Get Focused on Predictive Maintenance - Get Uptime
June 16, 2005
Balancing Tip
When balancing equipment where the length of the rotor is greater than twice its diameter, it may be necessary to divide the static and couple vibration. This will speed up the balancing job by solving each part of the problem individually instead of trying to do it all at once.
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
iPresentation Tutorial Invitation: Balancing Basics (6 Minutes)
June 16, 2005
Sensor Tip
Testing for Accelerometer Failure
Not sure if your accelerometer is working?
Here are a few quick test to help you determine if your vibration sensors is functioning properly:
• Lightly shake the accelerometer next to your ear. Do you hear a rattle? No accelerometers are made with loose parts! If you hear anything when you shake it, internal parts are loose.
• Connect the accelerometer to your data collector, and check for a reading. Many people simply shake the accelerometer to test for vibration measurements, but even on a working accelerometer this typically does not produce a sufficient reading. A better technique is to enclose the sensor in your hand and gently hit your hand on the table. NEVER bang the accelerometer on the table – grip it in your fist so that only your hand impacts the table. Unlike shaking it, this allows you to create high enough g-level vibrations to be read, without inflicting fatal damage to the sensor.
• Using your data collector, check the BOV level of the sensor. If the BOV reading is more than 4Volts off the nominal specifications provided by the manufacturer (above or below), the sensor has likely suffered permanent damage. A sensor BOV reading will detect virtually all internal electronic circuit failures.
If it fails these simple tests, its time to replace your accelerometer.
Maintenance Tip provided by:
Wilcoxon Research, Inc.
http://www.wilcoxon.com
Toll Free: 800-WILCOXON (945-2696)
Phone: 301-330-8811
Fax: 301-330-8873
Email:
