Noisy inverter

nwboater

New member
Is there a reason why the inverter in our new Unity TB is "noisy"? It makes a humming sound that is also heard on the FM radio I have plugged into an AC outlet. I can call the dealer but thought I would start here -- Thanks!
 

icarus

Well-known member
Most inverters have a slight 60 Hz buzz. Cheaper, MSW inverters tend to be worse, in some case much worse. A MSW inverter may also induce noise into a radio. Try reversing the plug on the radio where it plugs into the outlet. May not make a difference, but many inverters have floating neutrals, and reversing the plug may help.

Icarus
 

nwboater

New member
The inverter no longer makes the loud hum it did previously. When I told the service manager that I once powered a small coffee maker (1000 watts) using the (600 watt) inverter, he said the inverter probably ramped up to handle the load and stayed at that setting. After 2 weeks of "resting" and only putting light loads (FM radio) the inverter reset to it's factory default settings. I think I dodged a bullet on that dumb move!
 

smiller

2008 View J (2007 NCV3 3500)
The inverter no longer makes the loud hum it did previously. When I told the service manager that I once powered a small coffee maker (1000 watts) using the (600 watt) inverter, he said the inverter probably ramped up to handle the load and stayed at that setting. After 2 weeks of "resting" and only putting light loads (FM radio) the inverter reset to it's factory default settings.
A service manager actually said that?
 

nwboater

New member
Correct. That was his speculation and I can confirm that the loud hum is no longer present. Currently we're on the road and today slow cooked a pot of beans in a crock pot pulling maybe 150 watts continuous during a 5 hour trip...the inverter was operating quiet as a mouse when I checked during a rest stop.
 

BWeaver

Bweaver
Just wondering: Did the hum sound perhaps like a fan? We've had our Unity hooked up to AC for several days. Now that the weather is very hot I hear a hum coming from the inverter area in the cabinet under the passenger seat (driver's side) on our IB. We haven't run anything but lights.
 

Graphite Dave

Dave Orton
Another thing to consider is only turning on the inverter when you need 120 volt power. Inverters use battery power even without any connected loads. My 1000 watt pure sine Magnum MS1012 will use 7% of my 255 amp-hr house battery if I leave it on overnight without any 120 volt power being used. A simple solution to "increase" the capacity of your house battery bank. Another benefit is no noise while it is off.
 

nwboater

New member
BWeaver, no fan noise, the loud hum was from the overloaded transformer, which now operates quietly.
 

Don Horner

2012 Unity IB
My wife can hear a hum from the Magnum inverter, I can't. She claims I'm hard of hearing. the truth is, she has ultra acute hearing, and mine is normal...:thumbup:

I told her if she wants her iPad charged while we're boondocking to get used to the hum...:tongue:
 

blue

2011 LTV Unity CB
I thought iPads could be charged through a USB connection. If so, charge it from the 12V power source (cigarette lighter) so that you don't have to use the inverter.
 

Don Horner

2012 Unity IB
I thought iPads could be charged through a USB connection. If so, charge it from the 12V power source (cigarette lighter) so that you don't have to use the inverter.
Or the 12V outlet located in the overhead entertainment cabinet (TB).
I accidentally left my 12v chargers in the other vehicle and had to use the inverter to charge through the 120v connections. I had laptop, Android tablet, iPad and 2 phones, an electric razor and cordless hair trimmer plugged in plus running the TVs, a wireless router and a Ubqiuity WiFi antenna! We have solar panels, so can leave the inverter on 24/7 without battery woes. I just completed a 6 week road trip without ever connecting to shore power. However, the inverter, which is mounted under the bed on the IB models, does emit a slight hum if you have sensitive hearing like my wife.
 

nwboater

New member
Don, on the TB model the inverter is located under the starboard bed, where my wife sleeps. She too complained about the hum so I installed sound deadening material (lead lined) inside the cabinet and it made a difference. Careful not to block the vent that allows heat generated by the inverter to exit the space (may be different on the CB model).
 

Don Horner

2012 Unity IB
Don, on the TB model the inverter is located under the starboard bed, where my wife sleeps. She too complained about the hum so I installed sound deadening material (lead lined) inside the cabinet and it made a difference. Careful not to block the vent that allows heat generated by the inverter to exit the space (may be different on the CB model).
Good idea -- do you remember what material you used, or where you got it? Here in Okeechobee, it's either Home Depot, Walmart or mail order...but I can't image there are many more stores on Whidbey Island. By the way, I like your avatar -- is it photoshop, or do you really have the cool bird on the Unity? Have you ever seen the movie, Howard the Duck? :thumbup:
 

alichty

2014 LTV Unity TB
You should be able to find sound deadening material like Dynamat at any car stereo shop. There are a number of places that sell it online. I have used it for sound deadening on all of the last 4 or 5 cars I have owned and have it in the doors of my Unity TB. Very effective stuff :thumbup:
 

nwboater

New member
Don, as Alan suggests, you can use most any sound deadening material available -- I used left over material from my boat. About our Duck: before buying our motorhome we we're shopping for a newer, larger yacht to replace our 40 foot trawler. In the end we chose to go RVing for a few years. The boat my wife has always wanted is called the Diesel Duck, so she named our Unity "Duckin' Out!". I found the image on the Internet, licensed it, and sent the file to a graphics shop that specializes in making boat names. The whole project cost a couple hundred bucks. We're currently on a year-long circumnavigation of the continental US...presently near Minneapolis and on our sway to Nova Scotia and coastal Maine.
 

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Don Horner

2012 Unity IB
Don, as Alan suggests, you can use most any sound deadening material available -- I used left over material from my boat. About our Duck: before buying our motorhome we we're shopping for a newer, larger yacht to replace our 40 foot trawler. In the end we chose to go RVing for a few years. The boat my wife has always wanted is called the Diesel Duck, so she named our Unity "Duckin' Out!". I found the image on the Internet, licensed it, and sent the file to a graphics shop that specializes in making boat names. The whole project cost a couple hundred bucks. We're currently on a year-long circumnavigation of the continental US...presently near Minneapolis and on our sway to Nova Scotia and coastal Maine.
Thanks. I've had our Unity for almost a year and have been frustrated by that blank rear panel. Recently our daughter, a music director, suggested we get a graphic with a snippet of musical score for "Merrily, we roll along..." Only those who read music would "get it" :thumbup:.

If your circumnavigation gets you to Florida, and if you happen to cross the state north of Lake Okeechobee on state road 70, you'll pass our house. Give me a yell and stop by...I have 30A electric and good water hookups and my "home made" dump station, on 7-1/2 acres, so there is no problem with space...

We were near Whidbey Island on our own cross country trip in 2011, coming from British Columbia, but of course one does not causally "drive by". Ours was only 4 months, but we did New England and north a different time. That was in our LTV Free Spirit van, which was fantastic, but also led to us up-sizing to the Unity IB.
 

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