What is the effect of using infrared windows on certified enclosures?
A. -If the panel that you intend to fit the IR window into carries any certification marks then these should where reasonably practicable not be breached in any way. In the case of a panel with UL certification, you should only consider using UL recognized components; a question that is regularly asked is how does field installation of IR windows affect the UL status of the panel? The component (in this case, IR window) can be field or factory installed. The issue is the listing of the product in the field to which it is installed. Installing this product in the field does not negate the listing mark. Customers often modify assemblies that are UL listed and marked. Any modification done in the field is not covered by an existing UL mark. Therefore, UL is not responsible for the certification of these listings. When changes are made to listed assemblies that affect the rating of the equipment, UL will do a field inspection of the modified product to re-certify the equipment meets UL req
