This evening while in bathroom, I noticed a strange sound from rear of coach. Upon a lot of snooping, finally found it coming from the speaker / amplifier system under the end of bed pedestal. So I disconnected the power to it as I never have used it. All went dead quiet, Now wonder how much of a load that put on the battery system while dry camping ?
Could be a few hundred ma, can check later on actual amount of battery drain it had.
The crazy part, I never gave that equipment a thought, now wonder what else is not needed.
Any guessers ?
In my case, with the Bose system off, I believe my bedroom speakers are being "powered" by hum/noise/interference from the nearby ATS that I haven't quite been able to fully cure yet.
Hi Bob, I would guess the hum you hear from your auto transfer switch, that style of contactor is magnetically held it, and if anydirt/dust/rust on the pole shoes, it will hum and can be quite loud as it gets worse. A common issue with any magnetic contactor, they will all hum from rust/dust/dirt. Have taken many apart, cleaned, sanded or what ever needed to clean up and make quiet again. In my business, this is a common issue on the older designed switching gear. If I ever have an issue with either or both ATS units, I will switch over to the ASCO Series ATS units. They are slightly more complex, but do not use any energy to maintain in either position, so no noise, no heat and no power needed to maintain.
Most likely will remove the Bose sound system from bed area, that will provide easy installation space along with a upgrade suppressor. Never a dull day ;D
Cheers
On our 1997 coach, the speakers on the pedestal for the bed are connected to a separate radio in the corner cabinet on passenger side.
Dave M., that's interesting. I've always wondered why some buzz and others don't. The term "pole shoes": Are those the laminated plates that carry the mangnetic flux ? I'm invisioning where these plates stop against the base and the 60 Hz making them vibrate against the dust, dirt and rust?
For sure John, once you get into the two magnetic contactors, if the one pulled in is humming, just press on it with a finger, screwdriver or what ever, and the humming noise will stop or change. From there to solve the issue, you can do different things to check for the problem, if you have a can of compressed air, try blowing between the stationary and movable poles, if lucky, that will remove any dust or dirt, not rust. If it does not solve the problem, dissemble the contactor, then it will be clear what is needed to clean it up.
Over the years, we have seen these used on up to 400 amp 3 pole contactors, and they can and do make a lot of noise when dirty. Once you get into it, it is sort of an intuitive type assembly.
I have one contactor that makes a slight noise, only hear it at night when dead quiet and I listen real close. Easy to say heck with it and go to sleep.