Inverter Noise

[TIMEYES]

Hello

A few days ago, we started hearing intermittent loud clunking noises from our inverter / charger (a Freedom 458 Combi 15D) when hooked up to shore power - as if something is banging against the casing. The “events” range from a single clunk to a short series of clunks without any pattern. For some reason, this seems to occur more often during the evening when it's then noticeable any lights that are on briefly dim.

We've stayed in three different parks since this started happening so I think that rules out an issue with the supplied shore power.

We are in the process of replacing our four 6v Lifeline AGM house batteries which have come to the end of their life - they are at least nine years old and no longer hold any real capacity. Also, one of the batteries has developed a leak as I found its + terminal and the connected lead covered in a white deposit.

I’m hoping the issue will be rectified by the new batteries but would appreciate any thoughts as to what is actually going on in case the situations are unconnected and it’s really a fault with the inverter / charger.

Thank you in advance.

[beemergary]

1 hour ago, rm.w/aview said:

If there is a cooling fan there may be a loose nut, screw, or something that the fan is smacking around. 

Time to get out a few tools. Inverters need cooling ability.

 

[Kirk W]

 

I’m hoping the issue will be rectified by the new batteries but would appreciate any thoughts as to what is actually going on in case the situations are unconnected and it’s really a fault with the inverter / charger.

I would be very surprised if the new batteries resolve the noise problem but there is nothing wrong with doing that first since you plan to do so anyway. There are several possibilities that come to mind and the first I thought of is the relay that shifts between inverter and converter operation. There is also a transformer inside and if the iron core gets loose that too can move and make noise. Without hearing the noise, I am only guessing and how loud it is would play a part as well as how metallic that sound is. A big factor in working on things is always the accessibility of the component and if possible, I would remove the cover and observe it while it makes that sound, if possible. That will probably help a great deal to determine just what part of your unit is making the noise. 

[hemsteadc]

Perhaps this other dicussion will help:

http://www.rvforum.net/SMF_forum/index.php?topic=67840.0

 

[TIMEYES]

Thank you all for your input, especially hemsteadc for directing me to the discussion on rvforum.net. I can relate our issue to everything described / discussed there - The cooling baking tray analogy was spot on and I've now observed movement of the top of the casing as the clunking occurs.

Until we do swap out the house batteries (which we'll probably now delay until next year as we've only a few weeks left of this year's visit) I'll simply turn off the charging facility at night and see how that goes.

Thanks again, cheers.

[Dale P]

I am going out in space. The clunking may be a solenoid that connects 2, separate battery banks together.

I would be tracing out cables and searching thru diagrams