Dirty AC (Iota IDP30)

[BobM]

I've had this issue ever since I bought my Raven. If I use an AC power adapter for my laptop I get a loud buzz when the audio out is plugged into my factory installed stereo system. Since I rarely use hookups when I'm camping, I have ignored this. Since I had to use a hookup site recently I noticed this still happening. It's so bad that I can't hear my movie. To override It, I used a small 150 W DC to AC converter to power my laptop and no noise.

When I got home I tested it again with my house AC wondering if the campground AC was dirty. Low and behold, same noise problem when I plug my house AC to the camper and plug my laptop power supply to the AC outlet in the camper. Just for fun I used the same extension cord that went to the camper and plugged the laptop power supply into it. No noise at all through the stereo.

I'm sure that the Iota power converter is the culprit. Is this normal. Is it the downside of using that product or is this a known issue that needs to be fixed? Like I said, using my 150 W DC to AC is a work around but it has a little noise (not through the stereo) when the Cooling fan kicks in. My guess is that the noise issue is coming from the distribution panel since I assume the converter is only supplying power to the battery

 

[Wandering Sagebrush]

Any chance it's from EMI? Some LEDs are known to cause issues.

 

[BobM]

Like I said, I only hear it when plugged in the FWC ac outlet. Any other power source be it an extension cord or the DC to AC converter has no noise. The laptop and and power supply are in the same area in all cases. I'm sure it might be EMI but caused by the IOTA and only through the ac line. When I have my camper plugged into shore power but plug the power supply into the other mentioned option, no noise

 

[Wandering Sagebrush]

Like I said, I only hear it when plugged in the FWC ac outlet. Any other power source be it an extension cord or the DC to AC converter has no noise. The laptop and and power supply are in the same area in all cases. I'm sure it might be EMI but caused by the IOTA and only through the ac line. When I have my camper plugged into shore power but plug the power supply into the other mentioned option, no noise

I guess I should do a better job of reading . I think you're right.

 

[BobM]

I probably should contact Iota

 

[BobM]

I contacted iota and they never heard of the issue. I ordered one of these to try Tripp Lite 1 Outlet Portable Surge Protector/Suppressor, Wall Mount Direct Plug-in, & $5K INSURANCE (SPIKECUBE) https://www.amazon.com/dp/B00006B81E/ref=cm_sw_r_cp_apa_N0h1xbQR4J964

Sent from my SM-G930V using Wander The West mobile app

 

[Stan@FourWheel]

Hello BobM


I have never heard of that ? But not many customers are using stereos inside the camper these days.

Maybe one way to easily test it (troubleshoot), plug the camper into an AC 120V house outlet, and then open up the panel on the lower/front of your kitchen cabinets and turn off the "Converter" breaker.

Or, if you look under the cabinets, or inside your cabinets, you might (might?) be able to unplug the IOTA power converter (if the breaker idea doesn't do the trick), to see if that stops the noise ?

The 120V AC outlets run independently of the IOTA power converter. The only thing the 30amp IOTA does is power the camper with 12V DC current. But that said, the power converter does plug into a 120V AC outlet inside the cabinet for its power source.

Curious to see what you find out. Let us know.

Thanks.




.

 

[BobM]

Thanks Stan, I will check that out especially since the filter didn't work. If that isolates the problem, I will then plug the converter into an AC extension cord. This should pinpoint whether it's the converter or the distribution panel.

 

[PaulT]

You might get an AC outlet tester to see if the on board outlets are correctly wired. If an error is indicated, the wiring should be corrected. If no error is indicated, it may be that the Iota AC wiring is not correct in which case, have an electrician check it.

https://www.amazon.com/Electrical-Receptacle-Outlet-Ground-Tester/dp/B0012DHVQ0
You can pick an AC tester at most any hardware store.

Paul

 

[BobM]

I ordered the tester. Stan, I just did your check. First the breaker, still noise. Then pulled the panel out and disconnected the converter plug. First the noise went away but only because I didn't turn on the DC switch so the radio turned off. As soon. As I turned on the battery, the noise started again. So it's either bad wiring, bad distribution box or the yellow pigtail that plugs into the side of the camper is bad. I'll check again when I get the AC tester. Also I did check again by plugging the laptop power supply to the same extension cord that I plugged into the yellow pigtail and no noise

Sent from my SM-G930V using Wander The West mobile app

 

[BobM]

Got the tester and it says it's wired ok. Who knows. I will just have to use my 150w convertor and deal with the occasional fan noise. Next I will pull the stereo out to see if it's properly grounded

Sent from my SM-G930V using Wander The West mobile app

 

[wuck]

Sounds like the Iota was eliminated back in post # 10?

So, it could be a ground loop issue, which is probably the direction you're headed in by checking the stereo ground. Most electronic things plugged into an outlet have some sort of EMI filtering, usually consisting of capacitors from each line to the ground, as a result there are stray AC currents flowing around on the safety ground. The magnitude of these currents are limited by design for safety reasons.

So, what we want to do is to provide one path back to the safety ground to avoid contaminating other things.

In the distribution panel, the AC safety ground (usually green wire) should be connected to the panel itself, the camper chassis, the DC (-) ground, and any outlet safety ground contacts. Ideally, all these things tie together at only one point in the panel, so that loops cannot be formed. The AC neutral (white) should NOT be bonded to the safety ground in the panel or elsewhere (except of course in the house service entrance). Make sure all connections are clean and tight!

Beyond that, maybe trying a different (manufacture) power adapter for your laptop, a 12VDC adapter might do the trick.

 

[2020]

If it's a ground loop problem a ground lift adapter plug would be a quick fix.

I don't have this problem with my laptop in my 2014 Grandby.