12 Volt Reefer Electronic Noise

[jan bogart]

Recently installed a new Adler-Barbour 12 volt condenser/compressor to replace the 12 year old Grunert unit. The unit puts out an unbelievable amount of RFI with harmonics across the SSB band spectrum. They must all do this as I could hear at least three other units doing the same song on other - new to the anchorage - boats. It renders the SSB useless for comms on 80-40-20 meter bands and email is impossible. So, we turn the unit off for the period of radio usage. QUESTION... Is there a realistic way to filter or block this RFI? The A/B manual doesn't mention it. Any inputs would be appreciated. This has to be a common frustration.

Jan Bogart
S/V Vixen

[Wotname]

I am surprised you have not received any replies yet - this place is full of radio / electronic Wallas.

Anyway I will start the ball rolling even through I am not familar with the actual unit you are having the problem with:
Try to ascertain where the RFI is being generated - motor, electronic controls, etc. Then try to find out what is radiating the RFI - the dc power leads, the actual wiring from the motor, something in control board (microprocessor etc).

First rule of thumb - TRY to surpress the RFI at its source rather than try to stop it getting into the receivers (or whatever).
Second rule of thumb - try the easy / cheap fixes first.

I am not sure of your technical level of experience but maybe you can try some of the following random ideas and just see happens:
Connect the unit to a COMPLETELY fully charged seperate battery with very short leads - note what happens.
Fit a 3 wire RFI filter into the power lead (in series with the unit).
Temporary enclose the whole unit with plenty of Alfoil and ground that out with a short lead to the boats main earth system.
Probe around the power and any other accessibile wiring with a digitial AC volt meter selected to the millivolts and you MIGHT get some clues.
If I thought the motor was the source, I would be pulling it apart and fitting some caps (with very short legs) across the brushes (if any).
If I thought the electronic controls were the problem, maybe try fitting ferrite beads on all the wiring in and out of the circuit board or enclosing the board in some metal container (again grounded out).

Something to start with

[coot]

It's new? Have you tried complaining to the manufacturer?

[Beausoleil]

Originally Posted by coot

It's new? Have you tried complaining to the manufacturer?

This thread over a Rparts.com seems to indicat where this was a known A-B problem, and recently manufactured Danfoss units don't have this problem. A quick google seems to show that A-B knows this is a problem, and conviently offers an expensive fix for it. I'd complain if this is a new unit!

[David M]

There are noise filters for just that. I bought one from Newmar ages ago.

[jan bogart]

Thanks for the comebacks... David M - what did you buy? From where? Beausoleil - thanks for the Rparts link - very interesting and helpful. don't know if the Farraday cages can work aboard. Down here in the tropics, we need all of the air space around the unit as possible. Will continue to investigate..

[David M]

Hi jan,
This is it. Are you certain the noise is RF and not noise coming through the boats DC system? If its the DC system, then hopefully this noise filter can help. There is also a 10 amp version.

Have you contacted the manufacturer?...it seems electrical devices on boats should not be electrically noisy or RF noisy for the very reason you are asking. I would ask the manufacturer if this noise is normal.

I hope this works for you.

Noise Filter, 25A - Newmar Engine Noise Filters

David

[davidharris]

Jan-
Sold my steel boat last December. Betsy says "Hi".
Had 12 v system w/ holding plate- Danfoss compressor- no noise....

David Harris 619-981-0419