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Old 04-10-2017, 01:14 PM   #1
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First hand inverter experience? PSW vs MSW?

Hey Everyone,

I have been looking at inverter options for my Bluebird and immediately focused on Pure Sine Wave (PSW) inverters and did not even consider Modified Sine Wave (MSW) units at all. For obvious reasons the PSW inverters are superior. ....

And more expensive.

This morning I got to thinking about the argument against MSW inverters. Popular opinion (fact?) is that there are a number of devices that will not play well or will not play at all on a MSW inverter. The argument sounds plausible to me.


When I converted my first bus in the early '90s there was no way I could afford a PSW inverter so I grudgingly put in an MSW inverter with the understanding that it had limitations.

I lived in that bus for almost 7 years and never found anything that did not play well on that inverter. I ran: desktop & laptop pc's, TV's, cell chargers, vacuum cleaner, convection-microwave oven, power tools and more.

Has anyone here had first hand experience with MSW inverters not working well with certain devices? If so, what devices?



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Old 04-10-2017, 05:50 PM   #2
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I ran a MSW for years in my semi. I ran a frig, microwave, computers. The only problem I had was the microwave clock was off and it was a bit down on power. In the bus I started with MSW, the induction cook top would buzz even when off. I switched to PSW because I didn't want to chance the inverter mini splits.
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Old 04-10-2017, 06:28 PM   #3
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My fridge would be less cold and the light would blink rapidly when door open.
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Old 04-10-2017, 08:45 PM   #4
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I don't even look at the clock on microwave...

It always looks like my old vcr
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Old 04-11-2017, 08:25 AM   #5
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I've had the same experience with MSW. Everything runs acceptably but the microwave seems down on power versus when on shore/generator power. I use a CPAP (BiPAP) machine at night but I run it directly off the 12 VDC system.
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Missy - 1998 MCI 102-EL3 - 1.7kW Solar - 10kWh Lithium
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Old 04-11-2017, 11:00 AM   #6
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Some devices aren't as efficient. My freezer rattles a bit. My friend's TV would audibly whine on a MSW. My laptop's charger would make a low buzz.

With that said, I run nearly everything from DC power, and I'm perfectly happy with my MSW inverter. I've got this one:

My inverter runs my chest freezer for half an hour or so per day (using it as a refrigerator), my TV, electric toothbrush chargers, power tool chargers, and for a few days every month a small electric heating pad. I've installed the same one on my boat. I like that it has a lot of surface area for cooling and has an auto-speed fan that doesn't make a bunch of noise just being on.

My friend who had the loud TV switched to this PSW inverter:

It's got a remote power switch which is nice, he used that to trigger his freezer with an external temperature sensor. It has a wattage readout that's not accurate at all until you're drawing 100W or so, but above that seems to give a reasonable readout. He's running his freezer,a TV, occasional power tools, and a small vaccuum.
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