Converter dying?

[Ev in Oregon]

When I moved full-time into my 1988 Bigfoot almost 5 years ago, the converter had a very slight hum, but I wasn't familiar with all the trailer's noises yet, so I decided to just keep an ear open.
Well, now I definitely need to pay more attention. The hum has become quite noticeable, and I suspect the end is nigh.
So... does a person have a converter serviced or maybe refurbished, or do I face the inevitable and have it replaced? Has anyone had experience with a refurbished converter? Do they even do that?
Thanks!

[Byron Kinnaman]

Originally Posted by Ev in Oregon

When I moved full-time into my 1988 Bigfoot almost 5 years ago, the converter had a very slight hum, but I wasn't familiar with all the trailer's noises yet, so I decided to just keep an ear open.
Well, now I definitely need to pay more attention. The hum has become quite noticeable, and I suspect the end is nigh.
So... does a person have a converter serviced or maybe refurbished, or do I face the inevitable and have it replaced? Has anyone had experience with a refurbished converter? Do they even do that?
Thanks!

Electrical hum in something like a converter or power supply are generally caused by the transformer's loose lamination. The easiest fix I can think of is get inside the converter. There should be four bolts through the corners of the transformer. Tighten them up, and should reduce the hum.

The hum has no negative effect on the performance of the converter.

[Ev in Oregon]

Thanks, Byron, I didn't even consider that. I'll give it a try tomorrow when I have more time & let you know.

[Ev in Oregon]

Originally Posted by Ev in Oregon

Thanks, Byron, I didn't even consider that. I'll give it a try tomorrow when I have more time & let you know.

Just an update: Because Life is what happens when you're making other plans, I haven't had a chance to seriously take a look at the converter. I did tighten a few screws on the housing, just because, but that was as far as I got. Didn't make a difference.



So, the year's not quite over, and I have my first project for 2019. Now I can quit wondering.

[Defenestrator]

If the converter is the original one from 1988, it may be worth looking into replacing it with a newer "smarter" multi-stage temperature-compensated converter anyways to get faster charging and better battery longevity.

[Ev in Oregon]

Originally Posted by Defenestrator

If the converter is the original one from 1988, it may be worth looking into replacing it with a newer "smarter" multi-stage temperature-compensated converter anyways to get faster charging and better battery longevity.

Good advice. I was thinking I'd need to replace it since indeed it is the original, but I always check with the folks here because I get such great advice. I know a decent amount about how a FG trailer ticks, but there's a whole lot more that I don't know!


I do believe the converter may have died, but the only clue I have is that the loud humming has stopped. When I put my ear right up to it, I can still hear a hum, but it's very faint.


And, here's where I divulge my complete ignorance of converters: I am living full-time in an RV park where I have full hookups. All interior lights and outlets are working, but I don't know what my next step should be. Do I need to do something to disable the converter? Am I damaging my battery now that the converter isn't working? Is the battery even in the loop anymore? Can I get by without a converter as long as I have full hookups?



Thanks!

[John in Michigan]

Hi Evelyn!

Your converter, or any converter, does the following things:

- Converts AC shore power (when plugged in to shore power) to 12 volt DC to power the 12 volt accessories (water pump, most of the light fixtures, etc) in your camper
- Includes a 12 volt DC battery charging circuit to charge your battery when plugged in to shore power
- Includes a 110 volt AC circuit breaker panel to power AC outlets when plugged in to shore power
- Includes a 12 volt DC fuse panel to power 12 volt DC accessories whether using converter power OR the battery

If all of your light fixtures, pump, 110 volt AC outlets, etc are working then your converter is still working. Furthermore, unless you are planning to camp while NOT connected to shore power, you don't need the battery.

[redbarron55]

No load or filtering from the battery might make the hum a little worse, but not an issue unless you need the 12 volts for a more sensitive electronic thing in the RV.

[thrifty bill]

With a 30 year old trailer I’d focus on long term maintenance items first like window seals, water piping, etc. as long as your lights and other 12 volt items are working then the converter is working too. Permanent set up probably means out in the weather 100% of the time. If so, leaks will create damage unless you stay on top of it.

[Defenestrator]

Do you have any sort of battery meter? That'll tell you whether the converter's working, at the very least. It should always be full. If you don't, you should probably get one. The Victron BMV-712 is very good, but a bit pricey and needs some installation. As a more quick'n'dirty check, there are 12V plug-in volt meters that'll give you a general idea of battery level via voltage. A more flexible but less convenient option is a digital multimeter. Not as simple to use, but not super complex and vital for troubleshooting electrical issues.

[steve dunham]

Originally Posted by Byron Kinnaman

Electrical hum in something like a converter or power supply are generally caused by the transformer's loose lamination. The easiest fix I can think of is get inside the converter. There should be four bolts through the corners of the transformer. Tighten them up, and should reduce the hum.

The hum has no negative effect on the performance of the converter.

Got to agree with Byron . If you can pull / remove the transformer then tighten the screws holding the laminated plates together , clean the transformer , dunk it in electrical epoxy ( thin coat ) and bake the transformer .
That will sometimes cut down on the noise
I would also put a scope meter on the DC output of the converter and see if there is a lot of AC ripple .

[Jon Vermilye]

If you decide to go the route of updating the converter, check with Randy at Best Converters. There are a number of replacement units that just replace the electronics so you don't have to rewire the 12v & 120v connections.

[Ev in Oregon]

Wow, so much great advice, not to mention a complete education in the whys and wherefores of converters. You folks rock!



The converter is still nice & silent, and everything is working fine. I'm beginning to wonder if Bigfoot gifted the 1988s with a converter that fixes itself.



For now, I'll keep an eye & ear open and see what transpires because I have a new problem, as of this afternoon. I'll post that under a new topic.


Never a dull moment, but totally worth it!

[GWMattson]

I assume that your converter was charging the battery and your 12V power was drawn off the battery. If the converter died, you will still have 12V power until the battery drains. A quick way to check if the converter died is to disconnect a battery terminal and see if 12V power is still there.

I agree with the comment about replacing the old converter with a new one. Power electronics and battery management has significantly improved over the years. Get a good quality smart charger.

[ad1449]

What you hear is the windings in the transformer responding to the 60Hz line voltage. They are normally "glued" to avoid the inevitable motion created when a electrical current passing thru a wire gives rise to a magnetic field (Maxwell explained this phenomenon in the 19th century).
The hum is becoming more pronounced because the wires are moving more than originally. Eventually, the wires will work harden and break resulting in your converter failing. Can't comment on rebuilt/refurbished converters.
RV shops will gouge you good for a new converter but there is a company selling converters superior to the classical RV converters. Check out Intellipower: search the web.

[Michael Pupeza]

Evelyn,
My 1993 had the above converter and when I did a close visual check of it -I was surprised it hadn't caught fire. The power transformer is screwed directly to the vinyl floor and was very charred and it ran HOT. The technology is primitive to today's battery charging requirements and the unit is easy to change out. DO IT! (That's my suggestion)
Progressive Dynamics has their Intellipower (sp) units with one that will easily just replace into the lower unit of the box. There are just a few, easily identified, wires and, in my case, everything stripped out easily and was replaced with the existing wires. There are MANY references and pictures if you do a search. Even under my name are several relevant articles. Good luck.
Mike .....>

[ststefan]

Our converter boiled our batteries over. We bought a new one off Amazon. It has a 4 stage smart charger so it won't happen again. A rebuilt won't have the smart charger built in. Here's the one we got:

PowerMax PM4 45A 110V AC to 12V DC 45 Amp Power Converter with Built-In 4 Stage Smart Battery Charger https://www.amazon.ca/dp/B01ER3LH3O/..._g04lCb33ZFM9C

[Ev in Oregon]

Originally Posted by ad1449

What you hear is the windings in the transformer responding to the 60Hz line voltage. They are normally "glued" to avoid the inevitable motion created when a electrical current passing thru a wire gives rise to a magnetic field (Maxwell explained this phenomenon in the 19th century).
The hum is becoming more pronounced because the wires are moving more than originally. Eventually, the wires will work harden and break resulting in your converter failing. Can't comment on rebuilt/refurbished converters.
RV shops will gouge you good for a new converter but there is a company selling converters superior to the classical RV converters. Check out Intellipower: search the web.

Thank you, this is just what I was curious about...what makes it tick (or hum, in this case). It's been several days now and the converter is continuing to be as quiet as a mouse. Go figure (I'm sticking with "it fixed itself" )



I am so grateful for all the advice. I'll research the replacement suggestions and go from there. You've all convinced me that I definitely need to upgrade.

[ad1449]

Since the noise has subsided I would think that the loading on the converter has been reduced for some reason. Could be that your batteries are now fully charged? Fewer 12V items on (lights, accessories such as radio)?

The larger the load on the converter output the more pronounced the hum will become.

Some good advice from other contributors regarding new converters. Since your coach is an older model you might want to consider biting the bullet and springing for a new converter.

[Keith2000]

Knowing nothing about your converter or where you are located, I wonder if the fan was the source of the hum and if it may have died. If the unit doesn’t overheat, I assume it would still run for some time without a fan. Especially if it is cool.

I hate electronics and they hate me. I was just throwing this out as a possible explanation for the continued operation after the sound quit.

Also, contact best converter, as mentioned above. Good people selling good products and they stand behind them. Even take the time to help out someone who is well outside their comfort zone, like me.