Refrigerator RFI

[SteveAE]

Hi,

I have been chasing a perplexing problem for awhile now so though I ask for group input.
I have a Norcold (model N611) refrigerator that generates RFI which
manifests its self on the AM broadcast band as an ~3Khz tone.
It is radiated from, I believe, the 12 volt power lines to the refrigerator power supply. I have tried:
- snap on RF chokes on all leads
- Aluminum foil shielding of the refrigerator power supply
- 0.047 uF caps across the power leads and to ground

Has anyone else had, and solved, a problem like this? And if so what was your solution.

Thanks,
Steve

On edit, I forgot to mention that I am using a portable radio (not the built in radio) to track the RFI.

[SteveAE]

Wayne,

Thanks. I will give something like this a try.

Steve

[Wayne_Dohnal]

The noise filter I used is this one http://www.mcmelectronics.com/product/AMERICAN-INTERNATIONAL-S-10ADS-/60-1050 . I originally got it to get rid of alternator noise in an amp and it did the job. One catch is that mine is about 20 years old, so maybe the current ones are the same and maybe they're not. Looks like they also have 15 and 25 amp versions. I spotted them also on Crutchfield and ebay.

[dougrainer]

Run a 12 volt battery wire direct from the battery positive post to the refer 12 volt input and see if the rfi goes away. Doug

[SteveAE]

SaltiDawg,

Yea, I have been working through Google. Good idea on the local car radio installer.

Steve

[SaltiDawg]

GOOGLE on: car radio rfi filter

Crutchfield has a decent discussion and offers up some $10-$20 filters.

Your best bet might be to visit a local auto stereo/electronics installer.

I'm currently dealing with an RFI problem between my Dash Cam and my Garmin GPS. Borrowing tinfoil from my helmet is helping.

[SteveAE]

Wayne,

Yea, "oh-joy".
Do you happen recall any specifics about the part you used for your h2o heater?
I have been thinking about building a L or pi filter with a RFC and some caps, but I hate to, as Scott says, "shot gun" it into all the various wires...to say nothing about getting it tuned to the right frequency in the first place.

Steve

[ScottG]

Wow, I have no idea then other than you could shot gun the solenoid.
Good luck!

[Wayne_Dohnal]

Oh the joys of modern electronics. I had a problem of the control module in the Atwood water heater messing up my rear view camera. Fixed it with a filter meant for car stereos in the water heater's DC power feed. Just a shot in the dark, may or may not help in your case.

[dougrainer]

What is your problem????? What does the RFI do that is causing a problem????? Doug

[SteveAE]

Scott,

The RFI is present only when running on gas.
When I turn on the refrigerator (on gas) the light comes on, but no RFI until the solenoid closes a second or two later.
I wrapped the solenoid real well with Al foil, but no reduction in RFI was noted.

Steve

[ScottG]

Well that's a bizarre one!
Does it do it if your on propane or just with the 120V heater?

Scott