IR – Outdoor Electrical
Two important elements facing a thermographer performing outdoor electrical inspections are environmental factors and safety.
Wind and sun will drastically reduce the effectiveness of an IR survey. Wind is heat transfer by convection, and it doesn’t take much of it to remove a serious thermal signature completely. The sun causes two problems. It will thermally load all of the components, removing temperature differences. It will also cause serious reflections, especially for shortwave cameras.
The best way around environmental problems is to avoid them completely. A calm evening or morning when the sun is not shining on the equipment is ideal, especially if it corresponds with high loads on the equipment. If this is not possible, it is vital to understand the effects that the environment will have on your results.
The high levels of energy in much outdoor electrical equipment increases the danger level when inspecting them. Two simple practises will go a long way to reduce the risk of serious injury or death. As part of the hazard identification which must be completed before any work is done, use your infrared equipment to look for hot spots before entering substations or approaching electrical equipment, not just overhead, but all around. You have a unique tool for seeing critical problems that are invisible to the naked eye.
Another very effective means of keeping the thermographer safe is the buddy system. Looking through an eyepiece or at an LCD monitor at the world around you can create tunnel vision. A thermographer may temporarily lose track of the physical dangers such as tripping hazards. Also, it is very difficult to perform CPR or First Aid on yourself in the event of a serious accident.
The high voltages involved in outdoor electrical equipment demand that we treat both the inspection procedure and the safety aspects with respect.