[RFI] Samsung refrigerator RFI

Paul Christensen w9ac at arrl.net
Wed Aug 8 18:32:51 PDT 2012

> Bad News ----  Appliances are exempt from the stringent rules.

Yesterday's news.


> The folks who made our washing machine were fully aware of this when I
> contacted them. I would, at the very least, file a report with the FCC. 
> This device is
> most likely not compliant with the conducted emissions requirements.

Unlike EU (my understanding of EU rules), there are no conducted emissions 
requirements through certification for appliances here in the U.S. 
"Appliances" are exempt from certification, even if the offending appliance 
uses a sub-assembly that generates +40dB/S9 noise.   The supreme irony is 
that a stand-alone sub-system like a CPU might otherwise require 
certification.  But if it's embedded into an appliance, it gets by -- until 
a complaint is filed.  Oh, and just what exactly is an appliance and what 
isn't an appliance?   See below:

"Sec.  15.103  Exempted devices.

(d) A digital device utilized exclusively in an appliance, e.g., microwave 
oven, dishwasher, clothes dryer, air conditioner (central or window), etc."

See the three letters "etc?"  That covers a lot of exempt devices.

The only salvation is that the operator of the device still owes a duty to 
mitigate emissions from an unintentional radiator, even if it's exempt from 
the certification requirement.  In essence, no proof of non-radiation is 
required to produce and sell an appliance in the U.S.  But Part 15 also 
states that if such an appliance becomes an unintentional radiator, the 
operator must avert operation until corrected.  Unfortunately, I had to 
invoke this provision on a nearby neighbor two years ago when the house was 
being rented to college kids who had purchased a micro-fridge (yeah, an 
appliance) from Wal-Mart to keep the beer cold in a bedroom.

> Fixing these devices one at a time is getting really old.  In my
> neighborhood alone I have dealt with 5 grow lights, 3 halogen lights,
> and one surveillance camera.  All have been Chinese imports.

Really old.  I've been at it now for about ten years, coinciding roughly 
with the proliferation of SMPS in wall-wart supplies and appliances.

>> My wife was so proud of herself when she bought a new Samsung side by 
>> side
>> refrigerator with energy saving compressor. Yes, it runs quiet and 
>> doesn't
>> use much juice, but the compressor drive has a 5 KHz supply, and as luck
>> would have it, it wipes out all the HF bands every 5 KHz. To make matters
>> worse, beside the 5 KHz birdie there's serious hash between the birdies.

Same here.  Last Xmas, I purchased a Samsung side-by-side unit with lower 
freezer.  Mine also uses a new energy saving compressor that runs 50% of the 
time.  Shame on me, I was enamoured with the sales price and in a moment of 
weakness, forgot about potential RFI.  Me, a guy who has been fighting it 
for a decade.  Can't we just leave some designs well enough alone that 
work -- and work well?

Anyway, I had to choke the AC line cord which brought spurs down by 10dB so 
that they are now exactly flat with the noise baseline on 40m where it was 
worst on the ham bands.  Some of the noise is being emitted fro the door. 
And oh, if I disable "energy savings" on the front door, the noise level is 
reduced.  Apart from that, the noise is really bad on AM broadcast.  I also 
contacted Samsung customer service.  Honestly, I just don't have the energy 
nor the time to take up another cause.  If anyone finds that Samsung owns up 
to the compressor noise problem, please let us know.  I really expected more 
from Samsung.

Paul, W9AC 

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