I just completed an upgrade to my little coach, where I added four group 31 AGM 12v batteries and a Magnum Energy MS2812 inverter. I'll type up a little photo essay about that later. Right now, I have a few operational questions.Any electrical engineers out there, I have some tech questions!Firstly, the manual states the inverter will cause TV and radio interference and to not locate it near either. So I have interference on my raido, on every channel, even the strong local ones. There are no OTA channels in my area for me to test tv reception. My inverter is located about 10-12 feet diagonally from my radio antenna, which is on the other side of the aluminum roof. The side walls of the rig are also aluminum. I'm not not sure how the interference is getting into the radio, but I suspect it's actually from the DC wiring and not the RF input.Secondly, when the inverter is on and inverting (ac disconnected), I can hear a high pitched buzzing / whine coming from the DC light bulbs. It is not super loud, but in a quiet coach, I can easily hear it. The DC lights are sharing the battery with the inverter, and I tried to provide a low impedance path for the small DC loads separate from the inverter, but I fear it is flooding the entire DC bus with some nasty switching noise / ripple and the batteries aren't providing enough capacitance to absorb it.I will get my scope out and take a look at the DC bus this weekend, to confirm my suspicions.As far as mitigating the noise, what options do I have. Should I put a choke on the supply lines feeding my small load fuse box. Should I get a big capacitor and put it across the DC bus at the fuse box (with a fuse of course)... or should I explore something else?

Look with scope first, then either cap or choke.

Good luck - this is normal for any high powered INVERTER setup. The Pure Sine Wave Inverters do better than the Modified sine wave inverters...Even if you install the Inverters down in the bottom compartment just next to the batteries the RFI interference follows the 120VAC connections to provide AC power to the rest of the trailer.Will take some real big efforts to eliminate all of it.I got hit with two RFI issues.. First was the INVERTER setup then it was the LED lights I installed that had built-in regulators. Solved the LED problem by using the cheap $4.99 ebay/China non regulated LED SMD boards... Still fighting the RFI issues with the INVERTER installs...I use a smaller Pure Sine Wave Inverter just for the Home entertainment items which helps alot with the RFI signals from the bigger 1500WATT Inverter setup I have. Make sure you GROUND the INVERTER direct to the frame ground using the solid copper ground wiring. This also helped me alot cutting down on the RFI signals.This is my floorplan layout showing where all of my units area located.I even experimented in temporarily mounting the heavy INVERTER in the truck and routed 120VAC cables from there but still got roughly the same level of RFI signals..I think I would have good luck using an isolation transformer on the 120VAC side with good short length grounds on the INVERTER chassis to frame ground. Finding a right size isolation transformer to fit the RV mounting schemes is a problem... You would think 1500WATTS in my case shouldn't that big of a transformer required to handle the loads. Maybe its time for toroids and filter chokes...Of course messing with TOROIDS then you may have to deal with the outer space folks living among us... This messes with their lifestyle I am told...Just my thoughtsRoy Ken

Wow, I would consider that kind of rf leakage to be unacceptable for such an expensive inverter. No problems like that with my Prosine 2.0.Sort of sorry to hear they warned you in the manual.I'd call up Magnum tech support and ask them for the fix or a return authorization!

Nah, I don't think there is anything defective. It's the nature of the beast. This unit is built to handle almost 400 amps DC continuously, so there is some beefy switching silicon in there, and parts like that are going to make some noise. Filter caps and chokes drive up the costs and introduce other problems, like Roy pointed out ... TORRIDS are a black art

Unacceptable. I've heard of MSW causing problems running some devices, but nothing like you've described.For that kind of money I'd return it and get a PSW. No noise anywhere. Isn't it toroids?

MagnaSine Inverter Questions | Good Sam Community

GordonThree
Explorer
Jun 27, 2013
Nah, I don't think there is anything defective. It's the nature of the beast. This unit is built to handle almost 400 amps DC continuously, so there is some beefy switching silicon in there, and parts like that are going to make some noise. Filter caps and chokes drive up the costs and introduce other problems, like Roy pointed out ... TORRIDS are a black art
bananadanna
Explorer
Jun 27, 2013
Wow, I would consider that kind of rf leakage to be unacceptable for such an expensive inverter. No problems like that with my Prosine 2.0.

Sort of sorry to hear they warned you in the manual.

I'd call up Magnum tech support and ask them for the fix or a return authorization!
RoyB
Explorer II
Jun 27, 2013
Good luck - this is normal for any high powered INVERTER setup. The Pure Sine Wave Inverters do better than the Modified sine wave inverters...

Even if you install the Inverters down in the bottom compartment just next to the batteries the RFI interference follows the 120VAC connections to provide AC power to the rest of the trailer.

Will take some real big efforts to eliminate all of it.

I got hit with two RFI issues.. First was the INVERTER setup then it was the LED lights I installed that had built-in regulators. Solved the LED problem by using the cheap $4.99 ebay/China non regulated LED SMD boards... Still fighting the RFI issues with the INVERTER installs...

I use a smaller Pure Sine Wave Inverter just for the Home entertainment items which helps alot with the RFI signals from the bigger 1500WATT Inverter setup I have. Make sure you GROUND the INVERTER direct to the frame ground using the solid copper ground wiring. This also helped me alot cutting down on the RFI signals.

This is my floorplan layout showing where all of my units area located.

I even experimented in temporarily mounting the heavy INVERTER in the truck and routed 120VAC cables from there but still got roughly the same level of RFI signals..

I think I would have good luck using an isolation transformer on the 120VAC side with good short length grounds on the INVERTER chassis to frame ground. Finding a right size isolation transformer to fit the RV mounting schemes is a problem... You would think 1500WATTS in my case shouldn't that big of a transformer required to handle the loads.
Maybe its time for toroids and filter chokes...

Of course messing with TOROIDS then you may have to deal with the outer space folks living among us... This messes with their lifestyle I am told...

Just my thoughts
Roy Ken
Mandalay_Parr
Explorer
Jun 27, 2013
Look with scope first, then either cap or choke.

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