Wednesday, March 20, 2019

What Standards and Certifications Apply To Infrared (IR) Viewing Panes?

This question is frequently asked by clients as they begin to research the utility of infrared inspection windows for their specific application needs. There are many standards and certifications that can apply to infrared viewing panes so, this communication will help to identify and explain the most prominent ones.

UL Recognized Certifications:

* UL 50V: This is the only standard, but more of a classification, that is specifically applied to infrared windows. It states: Infrared viewports are a fixed aperture, consisting of one or more openings or a solid infrared transmitting media, surrounded by a mounting bezel or frame, that provide a means for the passage of infrared radiation. Infrared viewports are intended for factory installation in doors or walls of electrical enclosures for installation in ordinary (non-hazardous) locations to allow the use of IR scanners for monitoring temperatures of the enclosed equipment on which the viewport is installed, without compromising the integrity of the enclosure with respect to access to live parts.

This classification is applied to two different product categories: Infrared Windows and Infrared Ports. Infrared Windows provide a safety barrier that separates the thermographer from the target environment. In contrast, an Infrared Port is a hole and when opened, it removes the barrier between the thermographer and the target thus increasing the risk of an accident. Knowing the difference between a Window and a Port is essential when determining the use of Personal Protective Equipment.

Certifications Relevant to Infrared Windows

UL 50E: This standard applies to enclosures for electrical equipment intended to be installed and used in non-hazardous locations in accordance with the Canadian Electrical Code, Part I, CSA C22.1, the provisions of the National Electrical Code, NFPA 70, and the provisions of Mexico’s Electrical Installations, NOM-001-SEDE, as follows:

a) Enclosures for indoor locations, Types 1, 2, 5, 12, 12K, and 13; and

b) Enclosures for indoor or outdoor locations, Types 3, 3X, 3R, 3RX, 3S, 3SX, 4, 4X, 6, and 6P

This standard covers additional environmental construction and performance requirements for enclosures. The general requirements for enclosures are contained in CSA C22.2 No. 94.1, UL 50, and NMX-J-235/1-ANCE (See Annex b, Ref. No. 10) or the end-use product standards that are to be used in conjunction with this standard. This standard does not cover the requirements for protection of devices against conditions such as condensation, icing, corrosion, or contamination that may occur within the enclosure or that may enter via conduit or unsealed openings. Where an individual product standard contains requirements that are at variance with those of this standard, the requirements of the individual product standard take precedence.

* UL 746C: These requirements set the impact and flammability standards for polymeric materials used in electrical equipment up to 1500 volts. Any plastic or polymer, as a part of an infrared window, must

pass flammability tests at room temperature, and must remain intact during an impact test performed at 0°C (32°F).

* UL 1558: These requirements cover metal-enclosed low-voltage power circuit breaker switchgear assemblies containing but not limited to such devices as low-voltage power circuit breakers, other interrupting devices, switches, control, instrumentation and metering, protective and regulating equipment. UL 1558 specifies static load and impact testing requirements for infrared windows utilized in these assemblies. These requirements cover equipment intended for use in ordinary locations in accordance with the National Electrical Code. These requirements are intended to supplement and be used in conjunction with the Standard for Metal-Enclosed Low Voltage Power Circuit Breaker Switchgear, ANSI C37.20.1, and the Standard for Conformance Testing of Metal-Enclosed Low-Voltage AC Power Circuit Breaker Switchgear Assemblies, ANSI C37.51. These requirements cover equipment rated 1000 V ac or less nominal.

Ingress Protection

* The Ingress Protection rating system is a classification system showing the degrees of protection from solid objects like dust or liquids coming in contact within the enclosure. The IP rating of an IR window should be the same or higher than the equipment into which it will be installed and ties directly to the UL50E ratings.

Canadian Standards Association (CSA)

CSA is accredited by the Standards Council of Canada, a crown corporation which promotes efficient and effective standardization in Canada as a standards development organization and as a certification body. The CSA registered mark shows that a product has been independently tested and certified to meet recognized standards for safety or performance.

Lloyd’s of London Register

Lloyd’s Register provides independent, 3rd-party approval certificates attesting to a product’s conformity with specific standards or specifications. It also verifies the manufacturer’s production quality system through a combination of design reviews and type testing.

American Bureau of Shipping

ABS Rules form the basis for assessing the design and construction of new vessels and the integrity of existing vessels and marine structures

Arc Resistance

The Arc Rating applies only to switchgear, not to its individual components. Even though infrared windows have passed arc tests, the rating is assigned to the switchgear assembly. Despite what you may have read elsewhere, there is NO SUCH THING as an Arc Resistant Infrared Window in of itself.


Infrared viewing panes may have many certifications depending on the specific application or global location where they will be used. The most common certifications are UL Recognized, CSA recognized and Lloyd’s of London. Partner with your inspection window manufacturer to determine the best solution for your specific application.


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