Warning Re: Magnum Energy Inverters

[HaRVey]

We just completed our first dry camping trip with our 2018 Thor Palazzo 33.2 and had issues with a few of our electronic devices. A little background on our rig - I set it up for occasional dry camping by swapping the batteries with LiFePo and added 680W solar, so adequate battery power/reserve would not be an issue and to minimize generator use.
First, my wife's heating pad failed (melted control) and the new replacement wouldn't even work. Second, her juicer and blender would not work unless we turned the generator on and unfortunately the generator died with only 59h hours on it...(going to Cummin Service for repair tomorrow...)
I called Magnum who said that the model inverter Thor installs (ME2012, modified sign) should NEVER be used with heating pads (many fires reported) and will often cause problems with anything with a motor and digital controls. Magnum also said that while the equipment Thor installs in their RVs will work (fridge, micro, etc.) that the modified sign wave will cause them to run inefficiently and significantly shorten the life of user electronics such as coffee makers, etc., compared to their Pure sign models (MS2012). The retail price difference between the two models is ~$500, so there is no excuse for cutting corners on something which can have severe safety consequences especially when Thor provides no such warnings with their RVs. A new inverter is now on order...

[TurnerFam]

we've used our ME2012 for over 4 years with no issues with any appliances, microwave, etc... but we also don't use the inverter to power HEAT related appliances like irons, hair dryers, coffee makers, curling irons, or heated blankets - Inverters are not designed for those HIGH DRAW amperage devices, regardless of whether modified or sine wave.

we also off-grid a lot... the generator is your best friend - use these items only when the generator is running, or plugged into shore power. Solar and Batteries are not good power sources for high amp heating devices.

You'll not find too many motorhomes with sine wave inverters until you move up into the higher-end of the scale. The cost difference IS a big deal - using a modified inverter is not cutting corners.


get your generator taken care of - and use it - it's your friend.


enjoy

[HaRVey]

Had our previous RV set up the same way but I installed/converted to whole home inverter and installed a Pure Sign inverter without knowing the difference at the time.
I spent the money to use my RV any way I want to and just like (or as close to) all of the conveniences of home.
My only objective is to share the information with others so they are not caught unaware as we were and end up frustrated or burnt to the ground.
I would at least warn my customers of the danger (maybe a sticker or two, they seem fond of those..).

[16ACE27]

It's not the heating part that has trouble with the MSW inverters, it's the cheap control electronics, especially in the heating blankets.

[HaRVey]

Great explanation on the IRV2 forum of the technical reality of modified sign wave limitations, warrantee issues with appliances damaged by them and acknowledgement by Thor of the issue and Thor covering the replacement of the mod sign inverter to pure sign under warranty.
Since i already replaced mine myself, Thor is reimbursing me their cost of the original ME2012.

Read post #21 and beyond by MSTURTZ -
Microwave Humming While on Inverter - Page 2 - iRV2 Forums

[Tebo53AZ]

What do I need to do to get Thor to replace the inverter from the modified to the full sine wave model. Thanks

[HaRVey]

I would reach out to Thor customer support to describe the situation and your concerns (premature failure of your appliances, etc.) and see what they say.
If you are not currently having problems when running off of the inverter the way I and others have, it may be difficult to convince them to take proactive action.

[TurnerFam]

Using an inverter in the wrong 'capacity' that it is designed for is not going to get your manufacturer to 'give' you something that the coach was not built with from the factory... though I understand your aggravation. You simply can't use 'heat' devices on an inverter, whether MWS or not - they are not designed for that type of draw. Some higher amp devices are also not suggested to work on inverters, such as the high amp blender you mention - but many times it's the electronics and motors of the devices, not the inverter.
You could try to run your roof air conditioner on your inverter, and it would not work either.

Since most of us with factory supplied MWS Magnum ME2012 inverters don't have the 'issues' you speak of, I can suggest that experience proves that it's not an 'inverter' fault. Use your GENERATOR for high amp draw and heating type devices, that's what it's there for. Using your generator is not a sin.

[HaRVey]

You're entitled to you opinion just like everyone else. I'm getting my information from Magnum technical support due to specific issues we had. Not sure what you consider high draw, but Thor connected the microwave, which IS connected to the inverter circuit and (according to the inverter screen reading) draws ~139 amps (heat pad or blender draw 18, fridge 13, TV's 11amp), unlike other devices like the ACs, water heater & washer/dryer, which you can't run off/through your inverter and only operate on shore or generator power. A "high draw" device like the microwave will consume battery capacity quickly (which is why we use the genny for it) but the inverters are designed for and can handle the load, it's just not an efficient use of battery capacity. Again, to each his own, but the facts are that Thor deisned and wired some circuits to run off or through the inverter, regardless of whether or not it is efficient to do so and Thor did not provide any physical, verbal or written limitations to the use of those circuits beyond fuses or breakers. The fact that appliance manufacturers will not warranty the repair of a device powered by a mod sign inverter should be clue.
I hope you and everyone else never have any issues with your RVs (inverter related or otherwise), but for those that do, hopefully this information is of some value.

[Beau388]

The following is attached to a recently purchased Sunbeam electric blanker and electric throw. "All of our products that are sold in the United States and Canada are manufactured and UL approved for 110-120 voltage. We do not recommend the use of a converter, transformer or other electronic device with our product. Converting the electricity may compromise the functionality of the product. Additionally, doing so will void your warranty." Just so you know.