The day I’ve faced a fire in electrical installation (career story)

It was May 2005. I was a student back then. I was in my final year of studies and as a part of the practical work program, I found myself in one Serbian electrical distribution system company. The idea of this was for me to learn there the competencies I will need to practice as a professional after graduation. Every Thursday for 2 months, I was going there and was assigned sometimes to engineers and sometimes to technicians to work with them for a day. One Thursday was much more different from others.

Two electrical distribution technicians were taking care of my technical training that day. The task was simple. We were going on routine checking of electrical cabinets in residential buildings. We quickly went through first few buildings, filling out our field reports – mainly about visual inspection and electricity meters sealing checks. For my fellow technicians it was relaxing assignment without usual stress they faced during corrective maintenance assignments.

Electrical installation fire: accident waiting to happen

There we were, eighth floor of a 30-years old building. One technician was checking the fuse box part of electrical cabinet and the other one was inspecting analog electricity meters. I leaned myself against the wall, filling out report data as instructed by them. And then it happened. There was a cracking sound like fireworks, repeated few times in one second. The technicians were backing up from the electrical cabinet as yellow sparks emerged from it.

One meter exploded with a bang and a plume of black smoke was visible in an instant as the meter caught fire. The lights went out. One of the technicians was laying down with an injured hand and the other one was trying to help him. Smoke and smell of burning rubber and plastics were spreading fast as we were running down the stairs and warning tenants about the fire.

Fortunately, firefighters were there in less than 5 minutes and extinguished the fire.

Electrical installation fire: what could be the reason?

Even after a few minutes, when the panic is gone and the adrenaline goes out of you, you start to ask yourself the only logical question. What could be the reason for this? The technician being involved reported that he was just touching the housing of the meter when it started sparkling.

We can point to several things that might lead to an electricity meter explosion.  This device is susceptible to arcing when condensation or other contaminants get into a meter. Other indirect conditions can cause them to catch fire. Overloaded conditions, undersized wiring, and physical panel damage increase the risk that a meter could heat up, cause an electrical short and possibly spark a fire.

A voltage surge that occurred in the past can damage a meter. When there is a power surge of significantly more energy than a meter would normally experience, a meter can be damaged without any visual manifestation at first.

Electrical installation fire: what was the reason?

After a technical team investigated the cause of the fire, a decision was made that electrical fault produced arcing due to a loose installation of wiring, ignited and spread through the meter’s material and onwards to the junction board.

Lesson learned

I am working now as an electrical installation maintenance engineer. I have never had an incident with electrical installations as a professional. It is mainly because of taking preventive maintenance seriously (for example, periodical thermal imaging inspections of 43 electrical cabinets in the facility that I work). But, honestly, there are days in your life when you need a little bit of luck along with it.

I hope you enjoyed my story and that it helped!
B.M.

What do you think of B.M.’s story and lesson learned as a student? How would you have reacted or have you been in the same situation?