Speaking at the 2012 NSW seminar of the National Electrical Switchboard Manufacturers’ Association (NESMA), Consulting Forensic Electrical and Mechanical Engineer, Mr Russell F. Lee said that PFC technology is good technology but needs to be controlled for prudent risk management. Mr Lee has more than 50 years of industry experience and is one of the foremost investigators of the cause of equipment failure.
He said that the energy saving Power Factor Correction (PFC) technology should be housed separately from switchboards and motor control centres to minimise damage and downtime resulting from any failures. He explained that PFC equipment should be kept in a separate and fire-isolated room away from the main switchboard, motor control centre or any other apparatus.
According to Mr Lee, it is all about prudent whole-of-life management of switchboard systems and application of PFC technologies, because PFC capacitors can and will fail. Capacitors should be checked after five years, and the alarm system should shut down the PFC system in the event of high temperatures.
Given the widespread use of metallised polypropylene capacitors, one should take the incidence of fires due to capacitor failure and ignition into account during the design, operation and maintenance of switchboards.
Factors underlying capacitor risk include:
- High operating temperature
- Sensitivity to moisture
- Failure to self-heal
- Sensitivity to harmonics
- Poor quality film
For reasons of safety and damage limitation, the capacitor should be kept separately, allowing it to burn in its own room with its own sprinkler, rather than destroying three or four modules of the adjacent board or contaminating others, greatly magnifying the damage and downtime.
Mr Lee also reminded the audience that the lowest first cost is not always the right approach when safety and reliability are concerned. The idea that it will become someone else’s problem should give engineers and tradesmen pause for concern, especially when WH&S laws in all States and Territories have implications for designers, manufacturers, installers and end users.
NESMA President Mr Yeh-Sheng Kuan and NESMA Treasurer Mr Mark Betcher welcomed seminar speakers and thanked sponsors who made the event possible, including Platinum Sponsors ABB, Austral Wright Metals, IPD Industrial Products, NHP and Schneider Electric as well as Gold Sponsors Bridex, Colterlec, Crompton Instruments and Selectrix.