By S Edwards, R&C Instrumentation
Electricity+Control, July 2015 (pages 18 – 21)
Enquiries: Steve Edwards. Tel. 032 946 2805
Download the full article on Infrared windows in PDF format.
NFPA 70E lists removal of panels on electrical equipment as one of the riskiest activities that a worker can perform on that piece of equipment. The risk is elevated because the most common arc triggers occur either because the panel covers are open or as a result of removing the panel covers. Closed-panel inspection using Infrared (IR) windows will eliminate 99,9 % of arc flash triggers during inspection. The core benefit of IR windows is that they comply with the OSHA and NFPA 70E focus on removing the risk of an accident – protection with PPE is only used as a last resort, and the implementation of engineered controls is only used where risk elimination and substitution are not feasible.
World leaders in switchgear manufacture have tested the IRISS Polymer version of the IR window and now offer Polymer IR windows as options when manufacturing switchgear. The list of users is growing daily and across all manufacturing areas like power generation, paper and pulp, oil and gas, automotive and mining – to mention a few.
How can we justify the installation of IR windows?
Refer to the model (see image) and put some time and costs to the different areas; you will be surprised just how much you are spending. Refer to the brief case study in this article (see pdf) and see how Stansted Airport in London did it.
IR windows are not intended to protect a user from an arc flash they are intended to eliminate additional triggers of an arc flash during an inspection and replace a high-risk activity with a risk reduction/elimination strategy during inspection. IR windows and closed-panel inspections help companies to comply with the OSHA and NFPA mandates to eliminate risk wherever possible; conversely, a protection strategy is acceptable only after other methods of risk elimination or reduction have been exhausted.
- Arc flash injuries are all too common, and every precaution needs to be taken to limit the risk.
- It is accepted the certain observations and measurements in electric panels must be done while the system is live.
- An IR window on an electric panel allows visual access to the internals with a reduced risk of arc flash.