[RFI] Troubleshooting AFCI Tripping Due To Amateur Transmissions

[Jim Brown]

On 1/3/2013 12:15 PM, Jeff Stevens wrote:
> A friend of a family member is experiencing an apparent RFI issue which is
> causing his code required AFCI outlets to trip,

I had issues like this in the home I owned in Chicago.  It was an old 
wood frame building, built right after the great Chicago fire (2x8s were 
REALLY 2x8), and the wiring was ancient, some of it even knob and tube.  
I replaced all of it, mostly in EMT conduit (thinwall), put GFCIs in the 
bathrooms and kitchens, all the same, bought at the same time.  One, in 
the upstairs bath, within perhaps 30 ft of my main wire antenna for 
80/40/20/15, would trip.  I replaced it with a left over unit bought at 
the same time, same batch, and no more tripping.

A GFCI (ground fault current interrupter) senses the difference between 
current on the hot and current on the neutral, and trips if that 
difference exceeds about 6mA.  There's circuitry inside to do that, and 
it's usually "lowest common denominator" for cost, even more so for the 
cheapest stuff that usually gets purchased.  Adding capacitance to those 
lines is a no-no, because it can contribute to leakage current, 
increasing or creating imbalance.

I suggest changing the GFCI to a premium grade unit as a first step.  I 
hesitate to recommend any specific brands -- virtually everything is 
built off shore, el-cheapo grande, and it's hard to find an engineer to 
talk to about a product. .

73, Jim K9YC