Transformers and Safety Requirements
Category: Compliance and SafetyThe century-old power grid is the US is the largest interconnected machine on Earth. It consists of more than 9,200 electricity generating units, with more than 1,000,000 megawatts of generating capacity connected to more than 300,000 miles of transmission lines. Holding this mammoth infrastructure together are all types of station, substation and pad mounted distribution transformers.
With transformers being the major hub of collection and distribution of high voltage current, it is but natural that safety is a major concern, especially when they are located in public places and residential areas. Thankfully, there are also numerous techniques and both on- and off-line monitoring systems that can be used to increase operational efficiency, security and minimize unscheduled downtime.
This might be common knowledge but it’s good to remind ourselves that when dealing with electricity it is important to remember that it travels at the speed of light which is about 186,000 miles per second. It not only quickly, but also very easily, passes through things like the ground, metals, and anything with moisture in it. Electricity can also jump short distances through the air. Transformers receive and distribute very high voltage electricity, and leakages can thus be catastrophic.
Things to consider when dealing with safety related to transformers:
- Before installation of a transformer, inspect where it will be housed carefully and look for potential safety issues, including dampness, water and moisture, unless the transformer is designed for that type of environment.
- When access panels are removed for cleaning, all insulation surfaces should be inspected for signs of discoloration, heat damage, or tree-like patterns etched into the surface that are characteristic of corona damage. The core laminations should be inspected for signs of arcing or over-heating.
- Identify the type of electrical hazard and what agency maintains it. Determine if extinguishment is required. If so, use dry chemical or carbon dioxide for extinguishment of electrical equipment.
- Beware of gradient grounding.
- Assume all equipment is energized until the proper agency deems safe.
- Learn to identify potential hazards around your transformer: these include frayed wires, dampness, and more.
- Visually inspect your transformer on a routine basis and replace frayed cords or wiring to avoid leakage of electricity.
- If the transformer sparks, shocks, smokes or doesn’t seem to be operating normally, turn if off immediately. Avoid overloading the transformer by exceeding the rated load. Overloading can lead to overheating and extensive damage to the transformer.
- Put in place a regular maintenance plan for the transformer.
The issue of transformer safety gains a lot more relevance considering the fact that the US has a largely aging power infrastructure. Aging substation transformers installed in the 1960s and 1970s are rapidly approaching the end of their 'life'. These transformers didn't cause a blip on the radar during the last two decades, but with every year of the 21st century, their failure rates have become increasingly difficult to predict. This means that resource allocation and repair/replacement decisions are also becoming more and more exigent to maintain transformer safety. |
