Community Forums

Jasper7821 · 11-13-2013, 04:31 PM

I'm building a battery bank system for my mobile food trailer and was going to use a pure sine wave inverter because that's what I was told to use because of the electronics in a fridge, microwave, laptop computer.
Now I'm being told to use a modified sine wave inverter because it has smart start technology and is better for electronics.

Just looking for advice on which one to use.
Thanks

Smitty77 · 11-13-2013, 05:14 PM

For what you said you want to power, I'd recommend PSW. MSW may be just fine, but the equipment will run more efficiently on PSW, and then you also have it in case you add more sophisticated electronic appliances in the future.

We've lost two coffee pots, and a few other items over the years. So, when we did out 'getting ready for the next 10-15 years of usage, we added PSW for our coach.

Best of luck,
Smitty

Jasper7821 · 11-13-2013, 05:25 PM

My gelato case is $5,000 so I need it to be protected.

hogdriver · 11-13-2013, 05:30 PM

I'm not the expert on inverters. I took a couple years of electrical engineering but I'm happy when the wall plug works. I did have an interesting discussion with one of the Entegra tech reps at last month's Atlanta show. They are switching their coaches entirely over to PSW inverters despite the greater expense, because they are finding more integrated circuit boards being produced overseas that are not "happy" with the AC current generated by the MSW inverters. A MSW inverter is great for a hair dryer or toaster but someday your controller for your SAT dish, a circuit on your microwave might go out and the replacement part is built with these newer IC parts. It might not work, or might partially work. He said they were getting frustrated chasing gremlins and figured it would only get worse as newer circuitry comes online. I know they cost a lot more but a PSW inverter sounds like a better investment.

Davdeb1 · 11-13-2013, 05:36 PM

Quote:

Originally Posted by Jasper7821

My gelato case is $5,000 so I need it to be protected.

Exactly why you need a PSW. Don't even consider a MSW. PSW is what comes through household &
Commercial electricity.

Route 66 · 11-13-2013, 05:44 PM

Don't know about that.

I would only use a PSW inverter.

Quote:

Originally Posted by Jasper7821

Now I'm being told to use a modified sine wave inverter because it has smart start technology and is better for electronics.

Just looking for advice on which one to use.
Thanks

docj · 11-13-2013, 06:32 PM

Quote:

Originally Posted by Jasper7821

Now I'm being told to use a modified sine wave inverter because it has smart start technology and is better for electronics.

If you step back and think about it for a moment, what would make you think that a device that produces an electrical waveform somewhere between a square wave and an ugly sine wave would ever be 'better for electronics" than a device that produces a waveform fairly close to the sine wave power that comes out of a wall socket? IMHO whoever told this to you doesn't know very much about electricity or electronics.

Our coach had a Xantrex MSW inverter when we bought it and it worked pretty well with most of our electronics but some things would definitely not work with it and I was always concerned that some things were at risk even though they did work. When the Xantrx died we replaced it with a Magnum PSW inverter. It was more like 150% of the price of a new MSW inverter, not twice the price, but it didn't make sense to me to buy anything other than a PSW unit.

vsheetz · 11-13-2013, 06:45 PM

I multiple MSW inverters I use with my coach - for years, without issue. However, for your application I would go with PSW due to unknowns, the equipment costs, and cost of lost business and stock should there be a problem..

Jasper7821 · 11-13-2013, 07:04 PM

Thank you very much for the advice. I was already going to purchase a AIM 4kw 24v pure sine inverter for $1,300.
Then the RV guy today told me I don't need it and get a AIM modified sine wave and save the money.
I think I'll stick with my original plan. What's great about the AIM one is it has a 12kw peak for 20 seconds so if all the compressors just happened to kick on at the same time it wont shut down the inverter.

garbonz · 11-13-2013, 07:21 PM

I have a marine quality 800W MSW inverter that is just used for the stereo, TV and DVD player when drydocking. Seems to work fine...

terry735001 · 11-13-2013, 07:25 PM

i all so have a 24 v system and SW is the way to go

Md is fro AC motors nothing more

MD is like runing your car on back gas it well run but for how long
things well stop working in about 6 months with a MD

i fond out the hard way on this years ago

camaraderie · 11-13-2013, 08:44 PM

We spent six years with a MSW and I can confirm that a lot of the problems one hears about with them are exaggerations or urban myths. We powered microwave, LED TV, Computers and everything else that ran on AC with it with no issues EVERY DAY.
What I can tell you though is that for the refrigeration in your gelato case...ONLY pure Sine should be considered. Ditto residential fridges unless they have been certified for MSW.

tquarles · 11-13-2013, 09:08 PM

Well, here's some input from an electrical engineer:

For resistive loads, like the heating element in a coffee pot, it doesn't matter, both will work.

For motor loads, it largely depends on the type of motor whether it will work,but for all cases, the motor will run quieter and smoother with PSW. Much less chance of burning out the motor.

For electronic loads, remember that the electronics themselves run on 12v DC or so, so there is a converter to reduce the voltage - Think the power supply in your computer. Power supplies come in several different technologies, but the 'best' is switching power supplies. They are the most efficient, and they also frequently don't work on MSW unless specifically designed for it, which almost no mainstream appliances/computers/etc are.
A laptop uses the battery as a large filter, and probably doesn't care.
An OLD desktop will probably work as it most likely doesn't have a switching power supply.
a NEW, high-efficiency desktop will probably not work.

TechWriter · 11-13-2013, 09:29 PM

Quote:

Originally Posted by camaraderie

We spent six years with a MSW and I can confirm that a lot of the problems one hears about with them are exaggerations or urban myths. We powered microwave, LED TV, Computers and everything else that ran on AC with it with no issues EVERY DAY.

I spent 6 minutes with a MSW (after removing my PSW for repairs) and the MSW took out a powered subwoofer.

Don't believe the MSW myths -- get a PSW.