29-01-2011, 11:24 AM
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ELECTRICAL INSPECTIONS
Recent technical manuals published by National Fire Protection Association (NFPA) and the Inter-National Electrical Testing Association (NETA) prominently recommend the use of infrared inspection in the testing and maintenance of electrical systems
Dan Playforth
Thermographer Level II
Infrared Thermography
An Infrared Camera Senses Infrared Radiation
A Processor In The Camera Assigns Color To The Infrared Radiation-Different Color Equals Different Temperature
Enabling Us To Visualize The Thermal World
Benefits of Periodic Electrical Infrared Inspections
Predictive Maintenance...Allows Scheduling Of Repairs, Forward Buying
Reduces Downtime… Find It, Repair It, Before It Blows Up and Stops Production
Qualitative Infrared Electrical Inspection
Qualitative Inspection: The practice of gathering information about an electrical system by observing infrared radiation, recording findings, analyzing findings, and presenting that information.
Exceptions: are abnormally warm components that may be a potential problem. Exceptions are usually identified by comparing the thermal patterns of like components.
Electrical Inspection Items
Transformer
Pad Mount
Dry
Overhead
Service Entrance
Main Switchgear
Motor Control Centers
Disconnects
Bus Duct
Distribution Panels
Control Panels
Rectifiers
Drives
Capacitor Banks
Any Electrical Connection
Exception Analysis
Below is an exception. One of the conductor terminals is hot.
Hot Terminal Temperature…..203F
Left Terminal Temperature….156F
Temperature difference is …… 47F
Infrared Tips
Use a Certified Thermographer
Proper Training is vital to understand thermography
Cost Effective - Quality Camera is $20,000 to $50,000
Scan should cost from $800 to $1500 per day
Inspect When System Load Is High
Useless To Scan Under Light or No Load
Keep in mind that an infrared electrical inspection is only a report of the electrical system at the time of the inspection. Equipment that was off or unloaded because of cycling or scheduling may have problems that were not evident at the time of the inspection.
Do Inspections On A Periodic Basis
--Annually Good - Semi-Annually Better (at least first couple of times)
Insures that over period of time all equipment is inspected
Benefit of Electrical Infrared Inspections
"...From a return on investment perspective, infrared inspection programs have proven that on average for every $1 spent on infrared electrical inspections, there is a $4 return on investment for materials and labor from fixing the problems before it fails..."
"Cost/Benefits Analysis of Infrared Programs." Maintenance Technology Magazine June 2001
