Applications

Electrical Thermography and Infrared Windows

Electrical systems are the most critical items within office buildings and industial applications. There are considerable benefits to be gained by protecting these systems and reducing unplanned stoppages. Infra red cameras are one of several tools whose usage is on the increase. Recent advances in detector technology and hardware have allowed manufacturers to produce cameras at a price that we could only wish for 2-3 years ago.

Insurance statistics reveal that associated with electrical equipment damage, loose connections cause 25% of all failures to switchboards, switches, circuit breakers and cables. This type of fault is easy to detect using Infra Red cameras, trained operatives can now trace, quantify and trend the fault, this then allows the management of the site to plan repairs during planned stoppages instead of the panic reaction involved when sudden failure occurs, yet alone the possible risk of fire.

Utilizing properly constructed and certified Infrared Windows allows direct line of site access to “live” electrical components without exposing the thermographer to the “live” components. This assists in complying with the safety recommendations of NFPA70e and other bodies.

Infrared windows assist in reducing risk of arc flash. An arc flash is essentially an electrical explosion caused by electric current flowing through an arc outside its normal path. It generates high thermal energy (in excess of 7000 degrees C) and an explosive volumetric increase which blows off doors and can generate shrapnel. The amount of potential energy released is a function of Voltage, Available Current, and Duration (how fast can fault be interrupted). Arc flash is very dangerous event for all who work around low, medium and high voltage electrical equipment.

Arc Flash is caused by a gap between conductors being momentarily bridged. These “triggers” are preventable and include:

• Human error (dropped tool, accidental contact)
• Falling debris when door is opened
• Change of state (a failing component is pushed over the edge by inrush of moist air, dirt, dust, etc)

The vast majority of these are occur when a door is open or being opened.

Infrared windows allow infrared inspection without introducing any of these “triggers” of arc flash. The inspection occurs with the panel cover in place and the enclosure un disturbed. This allows more frequent inspections, safer inspections and reduced man power as the bolting and unbolting of covers is not required.