NFPA70E is scheduld for a revision over the next 18 months. The first "hurdle" is coming up this month when suggestions for changes can be submitted to the committee. That process is open to anyone who has an interest and details can be found on the www.nfpa.org website.

I have been in discussion with the Chairman of the committee as well as many thermographers about the standard. We would like to see the needs of thermographers be better addressed in the next edition.

I will be submitting language based on the following draft and would welcome comments from readers. Please email me directly and I will do my best to include them.

Here is the proposed language we hope to have included (NFPA will modify it to fit the standard), along with a rational for why we want the changes:
"A category will be created for the task of “non-intrusive inspection,” and will include, among others, infrared, airborne ultrasound, corona detection, or visual inspections. The inspector will have 1) a specified limit of approach for the distance at which the inspection is conducted, and 2) and will wear PPE appropriate to that limited approach and 3) will be accompanied by a qualified safety person (or work with a restraining barrier) that ensures the inspector does not come closer than that specified limit of approach. When access to conduct such inspections of energized equipment is through special windows or ports, rather than by opening the enclosure door, the limit of approach will be the same as if the enclosure door were not opened."

Rationale:
"Thermographers and others who are presently conducting non-intrusive inspections of energized electrical equipment have little guidance as to how 70E applies to them.
The risk of exposure to an arc flash is low because they should be cognizant of the risks associated with such an inspection; they are typically not the person who opens the enclosure; they stand back out of the arc-flash zone while equipment is being accessed; they spend only a brief time in front of the exposed, energized equipment; they do not touch the energized equipment for any reason; they do not need to break the plane of the enclosure door; and they are able to stand back from the equipment at least three feet (when space allows). Similar needs and circumstances exist for corona detection and airborne ultrasound inspections as well as, to some extent, visual inspections. Unfortunately, the most effective way to conduct an inspection using these technologies is to have a direct view of the energized equipment.
Thermography inspections, in particular, may represent a higher risk than some other activities because it is important that they occur as quickly after an enclosure is opened as is safe. The physical act of opening, and thus disturbing, the enclosure may increase the risk for any number of reasons versus the enclosure being left unopened.
We suggest that the risk associated with these normal inspection activities is low and that a special category should be created as a result.
In some circumstances it may be possible to install infrared-transparent windows or small viewing ports to facilitate an inspection. These can enable an effective inspection to be made without having to open the entire enclosure. The window or port is affixed with a solid cover that is secured in place when not being used for an inspection. At the time of an inspection the cover slides out of the way, exposing the window or opening. The infrared camera is place up to the window or over the opening to view the energized equipment inside the enclosure. When the inspection is completed, the cover is again secured in place.
In such circumstances thermographers using a window or port are working at a very close physical distance to the energized equipment but the enclosure door is not open. We suggest that the risk of exposure to arc flash is very low and that a special category should be created for this activity."

I will do our best to keep readers on this forum informed.

Thermally yours,

John Snell
jsnell@snellinfrared.com

Look like not many are excited about a standard for thermography.

Hi John, I have found on the internet an arc flash calculator which has been handy in validating the distance and calorie rating of clothing required how accurate it is i am not sure but considered it better than nothing. I have customers that wont let me scan unless I have arch flash equipment on even though I dont touch anything. The arch flash calculator gives you the calorie rating based on volts, amps, arch gap and distance if i remember correctly. In most cases I have used this and have been able to get by with 8 cal which can be acomplished with a thin coverall rated and not too badly priced $67. I witnessed 3 arch flash incodents this year during my inspections unfortunately. One in particular was a 480 control disconnect (60 amp fuses). The three feet in this case was not enough the electrician was blistered from wrist to elbow. I was about 8 feet away waiting for him to close the panel after taking pictures a component from the door latch fell across two fuses with a good 4' plus blast to start and a second smaller flash. The door was mostly closed and only a portion of his arm was in range but I remember the amount of flash that left that box well. I do not know if the smaller opening in the door increased the flash from pressure or ?. Hope this information is helpful to all and if I have mispoken on any of this feel free in setting me straight (A life time of learning)

Craig

Does NFPA have a stardard on application of thermography for industrial equipment monitoring?

NFPA70E appears to outline only safety aspects of thermography.

HI Josh, The NFPA (National Fire Protection Agency) addresses safety issues and because of the hazards of flashover in electrical equipment and the potential exposure to electricians as well as thermographers the verbage John is refering to will cover thermographers once completed.

Craig

NFPA 70B has a few words about thermography (suggested frequency of scanning)

In the U.S., NFPA 70E (2000 edition) will become law in August 2007 when OSHA updates the electrical safety standards. Basically, OSHA is incorporating 70E into a mandatory annex.

Ken Culverson