[Amps] PCB-based oil capacitors

[John Lyles]

Odd that with all the talk about the health hazards, the advantages that PCB compounds brought to HV capacitors isn't mentioned. PCB is an additive that raised the flash point of oils to the point were they were often considered inflammable. In capacitors and transformers,of course, this was a great safety advantage. We disposed of all our PCB-oil capacitors at work years ago - many hundreds of large 45 kV units at great expense. Subsequently, the end-of-life failures of the replacement capacitors (in pulsed load application, charged at line frequency) became ruptures followed by fire. About 8 years ago, we were getting a fire every month, plus cleanup, until we replaced 350 of the Dielektrol-filled (GE) units with new ones. All of the new oils are easily set afire if there is a significant spark inside the capacitor. 

I wish the country hadn't done that (outlawed PCBs) without having industry coming up with something as good or better for dielectric fluid. Nowadays capacitor mfrs. are using stuff like Rape Seed oil. You could drink it, and you can burn in it. 

73
John 
K5PRO