Are there any widely available IR transmissive plastics (in sheet/panel form) for custom IR panel windows? I know the portholes are available, but I'd like to do some homebrew windows on our switchgear and breaker panels. Plexiglas may not work, but are there different materials? Optical transmissivity would be great, but if its opaque to visible light, that would be okay too

How much freedom would we have in this regard without imposing on arc flash standards for electrical panels?

Firstly there is no perfect window material and pretty much everything you fit will have some problem or other.

Most thin film plastics will be transmissive enough to see partially through in infrared, but they are not all suitable for what you propose and you should proceed with extreme caution. I suggest you start with Polyethylene as a material to test it is pretty transmissive up to about 250µm thickness. You will have problems with fire protection, arc flash protection and mechanical protection.

Bob! Ireland! Homebrew; my buddies there upon making a batch would start drinking it green. Couldn't wait long enough. I thought they enjoyed the trots.

The minute you put a hole in the cabinet you are affecting the arc flash rating. Without some sort of third party rating and certification of your "portholes", you may be opening up a BIG can of worms in liability. You might want to check with your risk provider before you start modifying cabinets with "homebrew" additions. This is NOT something for a Do-it-yourself project.

You might also read NFPA 70E and the posts here on the subject.

Pls enlighten us on arc flash rating. Is it similar to IS or Ex rating?

http://www.infraredwindow.com/

That is a link to a company that commercially sells them. I think I'm to the point where it would be alot easier just to buy them.

Josh, the arc flash rating is a standard put forth by IEEE (www.ieee.org)(Institute of Electrical and Electronics Engineers) for safety surrounding high voltage equipment. It is not my specialty, but it's something everyone should be aware of.

Actually, its the NFPA (National Fire Protection Association).

www.nfpa.org

I guess you refer to this link:
http://www.infraredwindow.com/npfa70e.htm

I guess everybody knows arc flash is dangerous but it's better to know how to approach it systematically.

This message has been edited. Last edited by: Josh,

Here are some other sources for information on infrared windows.

http://www.infraredwindow.com/
http://www.hvir.com/english/index.html
http://www.crystran.co.uk/index.asp
http://www.mt-berlin.com/charts/chart_05.htm#INDEX7
http://www.sorem-france.com/index.htm
http://www.polytec-pi.fr/Judson/home-e.htm
http://www.irfilters.reading.ac.uk/home.htm
http://infrared.als.lbl.gov/IRwindows.html
http://www.ispoptics.com/
http://www.janostech.com./
http://www.opticalwindows.co.uk/irwindows.html
http://www.mt-berlin.com/index.htm


Just a word of caution, be very carefull fitting any of these, they will come with certification, but it will apply to the window only and not the fitting of the window. You could invalidate the switchgear manufacturers certification, so check with them first. I came across a case recently where the manufacturer said the equipment would need to be recertified after fitting windows. The bottom line was the windows cost a couple of hundred dollars each but the recertification costs pushed this up to over 9000 dollars each.

Also after fitting them take my advice and forget about temperature measurement through the window materials, it is extremely difficult.

Dear Sam,

We would be happy to help you. Although we do offer a polymer option, due to the low melting point and the fact that they are synthetics we do not recommend this option for anything other than 24VDC systems.

A better option for higher voltage systems would be the C-Range IR Sightglass, this option has been subjected to multiple Arc-Fault tests at different volumes, voltages and clearing times.

Some of the certifications we have to attend to are: UL, CSA, SIRA, ANSI, IEC, Arc-fault. These are expensive tests that are complex to complete and maintain. I would not recommend a homebrew IR Sightglass option, not because it would detract from potential sales, but because from a safety point of view what looks like a simple product is actually very complex to thoroughly certify.

On this point and in light of the websites recommended above, make sure you are diligent when selecting options;

1. In our experience, thin film polymers cannot withstand the combined overpressure and temperature of an arc-fault event.

2. Check the NEMA/UL50 testing. If you install a NEMA 1 product into ourdoor gear for example it will derate the equipment. We have seen an example of a plastic type product that had warped on an outdoor transformer making the seal suspect. European IP ratings are NOT equivalent to NEMA/UL50 Type tests, be firm with any supplier and ask for a NEMA/UL50 Certification. For clarity IP65 is NOT equivalent to NEMA 4.

3. Look into the calorie & pressure rating of the optic. This is the barrier between the thermographer and the potential arc-fault and can only be achieve by fault testing, exactly the same as Fire Retardent Clothing.

Drop me a line, we would be happy to look at the most cost effective options with you.

Best regards,


Tony Holliday
Hawk IR International Ltd.
Web.Infrared Sightglasses
Email. info@hawk-ir.com

I went through the process of investigating IR windows for HV applications and I have to say that I believe making your own window is not the way to proceed.

There are many standards surrounding electrical enclosures and violation of them could cause serious harm and put you in a position of liability.

I recommend purchasing certified windows designed for your application. IEEE C37-20.2 A3.3.1 and A3.6 will give you some details about enclosure openings and viewing ports. When looking at a vendors certification ensure it is certified for the correct voltage levels.

To comply with NFPA 70E you may want to consider that once an IR window cover has been removed you have a viewing window, clear or opaque, that may not withstand an arc fault incident (although many enclosures themselves may not either) and that personal protective equipment should still be worn.

Here's a tip I used to determine what size and how many IR windows I would need for an enclosure. On a de-energized cell, replace the door with a piece of panelling pre-cut to place windows in different positions. Then tape hand warmers to each point of interest within the cell.

When I completed my investigation in 2005 Hawk IR had a window with the most supporting paperwork that satisfied the IEEE standard.

Scott Webber
Ontario Power Generation
scott.webber@opg.com

Hi,

Atlas Inspection is a supplier of IRISS-Infrared Inspection Support Solutions, which include IR windows, dead front panel modifications, emissivity targets and infrared camera lens covers.

We offer IRISS IR windows in three standard sizes 2”, 3” and 4”. They are available in the VPFC line with the standard IR crystals that are commercially available and also our VPFR line with uses an IR2 lens assembly which is a combination IR transmissive polymer and aluminum grills to provide strength. We generally recommend the IR2 type as they do not have the failure modes of available short and long wave IR crystals.

Here is a brief summary on IRISS VPFR windows features, benefits and certifications:
• Work with all cameras
• Suitable for use indoor and outdoor without degradation
• Unaffected by moisture, vibration, airborne acids and alkalis and guaranteed for life of the installation.
• Available in true 2", 3", and 4" diameters
• Robust mounting retained from the inside of the panel.
• The only IR window to Meet IEEE C.37.20.2 section a.3.6 for viewing panes in MV and HV electrical equipment for metal clad up to 38kv and station type to 72kv and NEMA 4 open and closed.
• Recognized by UL to their standard 508/508a and UL 746 (Impact and Flame resistant)
• Help comply with recommendations of NFPA70e by keeping the enclosure closed and not exposing personnel to live electrical components
The use of a properly constructed infrared windows enables thermographers to conduct a thermal inspection without increasing exposure to live components, eliminates the triggers of arc flash (accidental contact, items dropping in to open gear, and change of state), and removes the need for a second qualified person to assist in opening covers.

Please contact me for further detailed information, testing and certification data, impact test videos, a product demonstration or for installation assistance and services.

Darren Billings
Atlas Inspection Technologies
206 227 0951 mobile
800 281 0650 toll free
d.billings@atlas-inspection.com
www.atlas-inspection.com
www.infraredwindow.com
www.g-m-tech.com

Hey guys,

I was hoping I might get some guidance here.

I am an EE intern tasked with deciding where to put the IR viewing panes in our switchgear and MCC's. As I started researching this I became aquainted with the whole arc flash hazard problem, (I hope I am never involved in one).

As I studied the Arc Flash Analysis done for the company I found that the labels for the PPE categories were placed differently on all the SG/MCC panels (for the same categories)? After discussing this with a senior electrician we agreed that every panel should have a PPE category label on it, does this sound reasonable? (and of course the labels need to be on the correct panels)
I am thinking that a panel with a PPE category of a three or a four would be an appropriate place to put viewing panes. But what about the "DANGEROUS" category, does anyone know if the arc flash resistant panes cover this category??

Then we get to the Actual placement of the viewing panes. the plant I work at is very large with many switchgear, MCC's, and DP's. (there's about 2 dozen pieces of equipment that would need viewing panes, not to mention all the panels on each piece) So therefore the question is what is appropriate, as far as what connections should be monitored? Some of the breaker panels don't have too much room for placing one pane but it doesn't seem as though we'd be able to see everything.

Any help would be appreciated.