Interference problems with Outback Flexmax?

I read on the Wind & Sun web site (OutBack controller tab) that there have been reports of EMI noise from the Outback Flexmax controllers and that the Xantrex XW-SCC or the Morningstar TS-MPPT charge controllers are currently the only ones certified to FCC Class B, Part 15. Has anyone experienced that problem with the Outback Flexmax controller?


  • boBboB Solar Expert Posts: 983 ✭✭✭✭
    Re: Interference problems with Outback Flexmax?

    All controllers make EMI somewhat. The question should be how much and at what frequencies ?

    What frequencies are you concerned about ?

    For MPPT charge controllers (DC-DC), the measurements are usually made in the range of 30 MHz to 1 GHz.

  • System2System2 Posts: 6,290 admin
    Re: Interference problems with Outback Flexmax?

    thanks, probably VHF-UHF comms freqs (right in the band you mentioned)

    the statement about EMI noise caught my eye, something to be aware of and take into consideration when selecting controller
  • boBboB Solar Expert Posts: 983 ✭✭✭✭
    Re: Interference problems with Outback Flexmax?

    Yes, it is a great idea to see how well the CC will work in a comm situation.

    I bought a new car last year and was toying of getting a hybrid. I wanted to put my mobile HF/VHF/UHF rig in there and all of the hybrids had a terrible problem with noise from internet forums and reports so I opted for a regular car with OK gas mileage. Very happy I did ! Driving is about the only time I get to be on the radio.

  • RandomJoeRandomJoe Solar Expert Posts: 472 ✭✭✭
    Re: Interference problems with Outback Flexmax?

    I have an Outback system, and I've never noticed any noise on VHF/UHF. I rarely do weak-signal work at VHF+, but the times I have I noticed nothing there either.

    However, my FM80 definitely makes noise on HF! It isn't always highly objectionable, but it's present in a number of places across the bands. Someone else here found the same thing (he was in a much quieter RF environment than me too, so it was far more objectionable) and said when he wants to work HF during the day he just turns off the charge controller.

    Actually, the biggest noise-generator on my system is the USB-serial adapter I use to connect the Mate interface to my computer! I have a program that collects data for my web page, and as long as it's running there's a LOT more noise on HF. It's about as bad as the fluorescent strip lights in the kitchen...
  • VicVic Solar Expert Posts: 3,082 ✭✭✭✭
    Re: Interference problems with Outback Flexmax?

    I agree with RandomJoe,

    The MPPT CCs that I've used here all generate some noise in the HF range. And, as one might expect, the lower the frequency, the greater the noise. Have no experience with the FM series, tho.

    Noise in the VHF and UHF rantges (I'd expect) would be greatly attenuated Even without any additional filters. Furthermore, any filters should become much more effective at higher frequencies.

    It is possible that many of the MPPT CC in the market have no filtering for RFI, such that a simple toroidal CM choke could be effective.

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
Sign In or Register to comment.