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2019-04-18

About Dummy Load PCBs and Oil


A Communicator Reprise: October 2014

Make a quick test to see if there is a problem


I picked up on a recent story that had some local input:


A while ago I bought an old Heath dummy load... full of oil. My main concern was whether the oil in it contained PCB's. Being an  older item I couldn't be sure. Since there is no way to tell by colour or odour I decided to research it further. What I found was a couple of simple tests that don't require any special equipment or chemicals and any one can do at home.

The first test is for PCB's in the oil, called a density test. Put a few drops of the oil in question in a glass of water. If the oil floats or spreads out on the top of the water it's free of PCB's. If it sinks then the oil contains PCB's. Since PCB's are heavier than water they will sink. Mineral oil is lighter and will float. However if any are detected this test doesn't tell the concentration amount.

The second test is a chlorine presence test. This test checks for chlorine in the oil to determine PCB presence.

This test is done by taking a piece of copper wire, dipping it into the oil and holding the wire over a flame such as a propane torch. Observe the color change of the flame. If the flame starts to turn green or blue green then PCB's are present. If the flame remains orange none are present.

The oil in my dummy load passed both tests. I changed it anyway because it smelled funny.

I can remember back when car AC systems were leak tested with a propane flame on a special wand. If the flame turned green, you were close to the leak area. I would imagine since refrigerant oils back then contained PCB's the same type of test was used. Later replaced by putting dye in the system and checking with a UV lamp.

So if any one ever wanted to know what might be in that old dummy load you brought back from the ham fest now is you chance to satisfy your curiosity.

The North Shore Amateur Radio Club also ran an article in their newsletter. Our own John Brodie VA7XB responded:

"In my previous job, I dealt with many PCB issues over the years. 
PCB is heavier than water, so a drop of it in water will sink, unlike mineral oil. That makes for a pretty simple test to determine if it is PCB or not.
PCB is only “carcinogenic” in the sense that 50% of all chemicals, man-made or natural, are “carcinogenic” under extreme laboratory conditions which have little or no relevance to real life. 

At BC Railways, we usually took our PCB  containing transformers and oil-filled capacitors to Powertech labs (an offshoot of BC Hydro) they had a process for destroying it."

John White VA7JW adds: 

"You are not supposed to use motor oil as it is not made to have electrical insulating properties, probably has a low flash point, is flammable, and “sticky" which is not wanted either." 

With thanks to WB2NGX, John Brodie VA7XB and John White VA7JW, who wrote an excellent article on the topic: http://www.orcadxcc.org/content/cantenna_va7jw.pdf




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