AC ripple in the DC

Discussion in 'Towing, Vehicles, Maintenance and Repairs' started by Wild Canadians, May 31, 2020.

  1. Wild Canadians

    Wild Canadians
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    We’ve owned our 94 Winnebago for about five years now. This year we decided to install a new Max Fan. Its awesome, except the Max Fan only runs on 12 volt. As soon as we plug into shore power it won’t work. Hubby is a electrician and he installed the fan. After doing some testing he finds a AC ripple in the DC. After a bit of research he did find one person saying this is normal. Hubby says should not be like that but motor homes are not his specialty.
    So we were wondering if anyone else had this problem. And does anyone know how to get the Max fan to like the DC power. Is there something wrong with our converter, anyone else have any problems with things not working while plugged in?
     
  2. NYDutch

    NYDutch
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    Which make/model converter do you have? The Parallax Magnetek converters commonly used in that era were known to be pretty "rippley", as well as notorious for charging failures that could boil the batteries. There are much better multi-stage converters to choose from today as replacements.
     
  3. Wild Canadians

    Wild Canadians
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    Ok was just confirmed that we do have the megneTek you wrote about. It’s a 45 amp model.
    What would you suggest we replace it with?
    Could we rebuild it with better parts?
    Or would it better to upgrade to a inverter?
    Thanks
     
  4. NYDutch

    NYDutch
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    Best Converter has several kits designed to update the earlier Magnetek converters. One of them should be a good match for your current model. An INverter converts 12 volts DC to 120 volts AC, while a CONverter converts 120 volts AC to 12 volts DC and typically includes a battery charger function. There are combination units though, but not in a format that would easily replace your current Magnetek.

    http://www.bestconverter.com/Upgrade-Kits-for-MagnetekParallax_c_64.html
     
  5. Bama Camper

    Bama Camper
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    Before you replace the converter, confirm that your battery is good. A battery, in addition to storing energy, acts as a filter to "smooth out" ripples from an unfiltered converter. If the battery is bad with open cells, or partially open cells, it will not filter properly and will allow "ripple" or AC superimposed on the DC. Poor connections on the battery posts could also look like a partially open cell battery.
     
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  6. Wild Canadians

    Wild Canadians
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    Interesting you should say this, as we have just bought a new battery for the truck and it this is when we start to realize that things are not that great. We already burnt out a battery and couldn’t figure how that happened. We found that one cable connection was completely rusted causing a bad connection and a this lead to a dead battery. Then the Max fan not working properly that has all lead to the main electrical panel. So we will be installing one of those shortly. I’m hoping things will run smoothly after that and the Max Fan will like to be plugged in. We love our MH and it runs like a top, even though it’s old it’s definitely a keeper. We don’t mind upgrading as this makes it more like new.
    Thank you so much for the help. I love this site always has great information. Thanks again.
     

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