Anybody have this sound from your Power Converter?

[KooKooBean]

Hi Everyone,

 

I have a 1987 Fleetwood Tioga Arrow, and it has the original Power Converter inside.

 

Unfortunately, I know absolutely NOTHING about electrical. After running my A/C for 30 mins or so, the Power Converter is making a loud buzzing sound.

 

Anybody ever ran into this problem? Is something getting ready to burnout, or should I replace some kind of circuit or whatever its called?

 

After keeping the A/C turned off for an hour, the sound becomes quiet, but its still there.

 

I tried uploading a short video, so it can be heard, but its says the file is too large to upload.

 

Any input would be appreciated.

 

Thanks,

 

Tim Miller

 

 

[Darryl&Rita]

Post it on Youtube, copy the URL, then paste it in the "Reply" window of this conversation. The forum software will automatically import the video to play here.

[Kirk W]

The noise and your air conditioner are probably only coincidental, or at least unrelated. The converter changes 120V-ac into 12V-dc power and the big change in voltage comes via a hefty, iron core transformer. Those cores are made up of layers and in time the layers begin to loosen a bit and that causes a humming sound, often referred to as "transformer hum." It is always there in any transformer but newer ones are usually quiet enough that you seldom notice the sound but as they age most of them also get louder. They volume also varies with the amount of current load so if the batteries have been discharged or you have a lot of 12V power in use, then the noise will be louder. Your air conditioner does not use 12V-dc unless you have one that is controlled by a wall thermostat, and even then it is only the thermostat and some control circuitry that uses 12V.

It probably means nothing at all and you just need to learn to ignore it.

[KooKooBean]

Thank you Kirk.... That was very useful knowledge. Just for the record, my RV has a wall thermostat in it. Its a 1987 model, so I guess this is all old technology.

 

Thanks again.

 

Tim

[KooKooBean]

Here's a video of my power converter Buzzing.....

 

 

https://www.youtube.com/watch?v=iFgfIsuUL3I&feature=youtu.be

[skp51443]

The old 6300 series converters can get noisy if they are charging the battery or if you have a lot of 12 volt stuff running. You really can't repair them so replacing it when the noise gets too aggravating is probably the best route. There are far superior converter options available today that are a lot easier on your batteries and can add to their lifetime so if you decide to replace it come back and get some suggestions for what to get.

[Darryl&Rita]

Agree with Stan. As a temporary fix, look for any loose connectors on the lid hinges, the plate the breakers poke through, etc. Any loose metal can really amplify the natural noise they make.

[oldjohnt]

I'm with Stanley and Kirk on this one. I owned a bunch of those old style Humming Buzzing hot Converter/Chargers in the 80's and 90's and they were all noisy, especially, as they noted under a heavy load. Many operated more like a constant voltage source, say 13.4 to 13.6 volts DC and could overcharge the battery over extended periods of operation. If you like and intend to keep the RV, ditch that old noisy buzzing unit and replace it with a modern so called "Smart" Four Stage Charger as they're not all that expensive and greatly improve battery charging and battery life. In the area around that Charger keep it clean and dust free with no clutter near it to allow for better air flow and cooling. The frequency you're hearing is 60 Cycle Buzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz as alternating magnetic fields attract and repel all those thin metal lamination plates. It could drive a body to drink lol

 

John T

[Kirk W]

I'd bet that Stanley is correct that you have the old Magnatek 6300 converter, which I think was the most commonly used one by RV builders in the 80's. If he is correct, I'd put that on my list of things to replace fairly soon as it has a host of features which make it less than desirable, although they did have a pretty long life. In the mean time, be sure that you frequently check your coach batteries for electrolyte levels as that converter tends to use a lot of distilled water and you will need to keep them at proper levels for long battery life. When using ours I always planned to add water at least monthly if plugged into power. Also, if you want to recharge a discharged battery you will find it does a much better job to use an automobile battery charger, rather than the old 6300.