Power supply RFI Issues.

[Cruiseomatic]

My 12VDC 60amp PSU gives of tons of RFI. Mostly between 25-30mHz. I've tried Ferrite cores on both 12VDC hot and neg, 120VAC hot, neutral and ground. Case grounding has no difference. It is coming off the supply wires that carry 12VDC. Sometimes its there, Others its not. I've thought about either an isolation transformer or a ground loop isolator. I think those are the same though. Only kick is, I pull about 50-55 amps from this unit and not sure how well a isolator would like that.

Here's how it happens:
PSU off, hot connected no RFI. On, RFI occasionally if not constant. Remove hot, RFI gone.

What else can I do?
Thanks.

 

[DaveNF2G]

If your power supply is of the "switching" type, then you will never be able to clean up the RFI. It is inherent to the design.

 

[Cruiseomatic]

Even with an isolating transformer? Like I said, It uses the wiring as an antenna.

 

[fineshot1]

My 12VDC 60amp PSU gives of tons of RFI. Mostly between 25-30mHz. I've tried Ferrite cores on both 12VDC hot and neg, 120VAC hot, neutral and ground. Case grounding has no difference. It is coming off the supply wires that carry 12VDC. Sometimes its there, Others its not. I've thought about either an isolation transformer or a ground loop isolator. I think those are the same though. Only kick is, I pull about 50-55 amps from this unit and not sure how well a isolator would like that.

Here's how it happens:
PSU off, hot connected no RFI. On, RFI occasionally if not constant. Remove hot, RFI gone.

What else can I do?
Thanks.

When looking for solutions to any problem on any equipment it is NECESSARY to
include make and model of said equipment and its history if possible(used or new).

 

[Cruiseomatic]

It is a PD4560. Basically a distribution panel for 120VAC and 12VDC.

 

[fineshot1]

If your power supply is of the "switching" type, then you will never be able to clean up the RFI. It is inherent to the design.

On many older designs yes that is true but "most" new switching supplies these days
are RFI free or almost none.

 

[fineshot1]

It is a PD4560. Basically a distribution panel for 120VAC and 12VDC.

Is this what you are talking about?

Inteli-Power 4560

 

[Cruiseomatic]

Thats it.

 

[fineshot1]

Thats it.

That unit is an RV DC to AC converter with a distribution panel for the DC
side of an RV battery. That noise is being generated from the DC to AC converter
part of the panel so it is not a normally used AC to DC power supply.

 

[Cruiseomatic]

There is no DC to AC converter. Just AC to DC. I know the noise is coming from the converter. Its coming off the 12VDC hot and using it as an antenna.

 

[Jimru]

There is no DC to AC converter. Just AC to DC. I know the noise is coming from the converter. Its coming off the 12VDC hot and using it as an antenna.

Hi,
Can you clarify what you mean by "using it as an antenna"? Are you in fact in an RV, using one of the legs of this unit as an antenna? If so, why?

 

[fineshot1]

There is no DC to AC converter. Just AC to DC. I know the noise is coming from the converter. Its coming off the 12VDC hot and using it as an antenna.

Per the downloaded installation doc of this unit there is NO AC to DC unit.

This unit is designed for the RV environment. Why would any designer convert
from DC to AC only to re-convert again from AC to DC. That would be so inefficient
and draw so much current off the RV battery in deplete it in short order.

 

[Cruiseomatic]

Not in an RV but a aluminum sided trailer house that I converted to use both 12VDC and 120VAC. As far as "using one leg..." is that it uses the 12VDC POS "side" or "leg". It is using the wiring as a TX ANT.
If there is no AC- DC converter, How does it charge the batteries or power the lights, Etc...?
It DOES have a AC to DC converter. That is where the RFI is coming from. I read the PDF, it only briefly talks about the converter. In order to have DC to AC, You must install an inverter.

 

[fineshot1]

Not in an RV but a aluminum sided trailer house that I converted to use both 12VDC and 120VAC. As far as "using one leg..." is that it uses the 12VDC POS "side" or "leg". It is using the wiring as a TX ANT.

I see the problem in the doc i downloaded. There is a charger for the RV battery to keep it
topped off and that is probably what you are talking about. That charger unit is not meant
to be used as a power supply and only to be used to keep the RV battery topped off and is
unsuitable for use as a power supply in the way you are trying to use it. The charger electronics
that senses the charge state of battery and and then initiates charging when needed is probably
what is giving off all of the noise.

Download the doc in the link i supplied and read it and make yourself more familiar with it.

 

[Cruiseomatic]

I was editing when you posted. It works as a power supply fine. And has ZERO noise in the line. But it emits RFI when connected to the "grid" of the house. But if I connect a radio to it with no antenna, it is fine. But I'm also not trying to use it to power a radio. However, it is producing RFI that makes using a radio hard to pointless. I've read the pdf's and even talked to progressive dynamics tech team. They are clueless about it.

 

[fineshot1]

I was editing when you posted. It works as a power supply fine. And has ZERO noise in the line. But it emits RFI when connected to the "grid" of the house. But if I connect a radio to it with no antenna, it is fine. But I'm also not trying to use it to power a radio. However, it is producing RFI that makes using a radio hard to pointless.

yes - that would be the battery charger itself emitting rf noise. Call the number in the doc
and see if there is any support from them they can help you with or go to the website, see
below:

Progressive Dynamics, I n c .

PD4500 Series Power Control Centers

Power Converters, Battery Management Systems for RV, Marine, Medical and Specialty Industries

For Warranty Service Call: (269) 781-4241 Ext. 159

 

[ridgescan]

At this point nothing to lose by trying a Faraday Cage. Get a metal box, place the offending unit inside that box and bond the box to the offender. Worked wonders for my modem
Zenith Transoceanic Faraday Cage - YouTube

 

[Cruiseomatic]

I actually tried that with foil tape it worked a "little" then the PSU began to overheat. The enclosure is designed for maximum heat dissipation because the designers were more concerned about audible noise than actually cooling so the fan is weak at air flow. I'll try it again but try a different way. Not sure if it will work since the wires radiate the noise and not the actual PSU. Put all the foil tape back, Same thing.

 

[Cruiseomatic]

Tried a clamshell type ferrite core I had laying around on the 120VAC going into the converter. If held right, The cores would rattle and sound just like the RFI I'm receiving.

 

[W2PMX]

As far as "using one leg..." is that it uses the 12VDC POS "side" or "leg". It is using the wiring as a TX ANT.

If you mean "that's what's happening", it's because the supply isn't designed to be RFI-free. Power supplies designed to be used in a radio environment, even switching supplies, are designed to generate as little RFI as possible, then that RFI is kept inside the power supply's enclosure.

If you mean that you're using the wiring as a transmitting antenna, that's one of the things causing the problem.