Infrared (IR) inspection is widely used in electrical maintenance programmes. IR windows make the inspection procedure safer and more cost-effective than ‘hands-on’ inspection.
However, certain key aspects need to be considered to get the best out of the maintenance programme. R&C Instrumentation highlights 10 important points.
- An IR window is an inspection point designed to allow infrared radiation to transmit to the outside environment. Simply, it is a data collection point for a thermal camera.
- An IR window does not provide shielding in case of an electrical explosion, or arc flash. It will, however, significantly reduce the likelihood of such an event because the electrical panels do not have to be opened.
- Wherever possible, polymer windows should be used rather than crystal windows. Crystal can shatter and is moisture absorbent, so it will fail over time, unlike polymer.
- Emissivity is one of the most important variables. When installing IR windows it is crucial to standardise the emissivity of the targets while the gear is open.
- Every camera has a field-of-view defined in degrees across a horizontal/vertical axis. Obstructions, such as phase dividers or cables inside the cabinet may decrease the actual field-of-view.
- As much information as possible should be gathered while equipment is de-energised, and a complete IR inspection should be done at the end of the window installation to establish a benchmark/baseline for future inspections.
- UL50 is the only standard that applies to IR windows, although it is more a classification than a standard. All other standards cited may have a bearing on some aspect, or use of a window.
- IR windows allow for inspections to be done with the electrical cabinet panels closed, so technicians or maintenance personnel are not exposed to energised components and the elevated hazards/risks they present.
- IR windows are safe to use, they eliminate risk where possible, provide for a systematic approach to data collection during inspection, and are cost-efficient.
- IR windows can save plant operators time and money, leading to a return on investment within the first or second inspection cycle.
By facilitating closed-panel inspections, the use of infrared windows eliminates 99.9% of arc flash triggers and completely eliminates injuries caused by accidental human contact to energised equipment during infrared inspection. IRISS infrared windows, available from R&C Instrumentation, are made of polymer rather than crystal, which means they are shatterproof, and they can be manufactured in any shape or size.
For more information visit: www.randci.co.za
