Possible to use modified sine wave inverter?

[Life In The Dog House]

I have decided to go ahead and do my own camper van solar install using Will's DIY Plan. I am on a tight budget and already have an Xantrex 1000w inverter that was purchased years ago. But, it is a modified sine wave and not pure sine. Would it do until I could afford a pure sine wave inverter?

 

[b.james]

If it is running what you want to run now then it would be fine . I had one and returned it because it would not run my modern TV without a hum. I bought their pure sine wave for an extra $45 and it works great.

 

[Life In The Dog House]

Thank you for the reply b,james.

I only asked because I have a modified sine wave in hand that I had purchased years ago; Right now I am living on savings which are quickly dwindling while getting ready to launch a new business, so I really need to make my dollars stretch.

I have everything sans a pure-sine wave inverter, charge controller, main 200amp bolt on battery fuse, and the copper wires/ends, which I was going to order on Amazon. last night. As the total of my cart items was quickly rising...I wondered if I could get by using the modified sine wave, which would keep my costs down for now. But, I am more concerned that I don't ruin anything i.e.) cell phones, laptop, Jackerys, my dc fridge etc., as these items are vital to both my business & life in general.

I have a very healthy respect for electricity, and documentation on solar is overwhelming; So, I was going to have one of my friends- who I trust 110% when it comes to anything related to vehicles- install everything in my camper van i.e.) Maxxfan, battery isolator, solar system, etc., but the timing is off, as my friend is building a new house.

After watching several of Will's videos on this forum- I think I can do the install myself, but have questions and I want to make sure I can safely do this install and not become a fried Popsicle stick.

Thanks again!

 

[svetz]

Modified wave inverters provide the same amount of "power" as their pure-sine wave cousins; where they fall down is anything that depends on a smooth wave; any sort of electronics like a TV/Computer or induction stoves. Those devices may work to some extent, but they won't work efficiently and probably draw more power or have more annoying side-effects than you'd like.

 

[Life In The Dog House]

Thank you svetz.

I knew there was a dirty/clean wave between the two; but was never sure exactly what it meant or what the end result would be.

Pure-sine wave it is!

Thank you again svetz (and b.james), I appreciate your help!

Have a great day!

 

[robaroni]

Modified sine is a misnomer, these are really modified square wave inverters for the most part. Certain electronics will have problems with them and anything with an inductive load such as AC motors run hotter because the load sees the square wave as DC at certain points in the wave. Without getting into the technical aspects of that (inductive reactance) suffice it to say if you can get a pure sign it's best to do so.
What you have to watch out for is cheap pure sine inverters that have noise in the wave and distort running inductive loads like motors found in fridges and washing machines.

The reason some small electronics run poorly on modified inverters is due to the fact that the switching power supplies in them don't handle the square wave well so you get things like hums that aren't filtered out.

If you're running a DC fridge like you say then this is a separate load that runs directly from a battery bank so it's unaffected by the inverter. Some of your electronics might run perfectly fine, if it doesn't you'll know right away and if I had hums and such I would invest in a pure sign inverter, you might save in the end. Things like toasters and heaters don't care if it's a modified wave.
Incidentally some modified inverters run much better than others. The old Trace inverters ran pretty well and we used them in the 90's a lot. It depends on how the wave is formed. You can have a modified wave with several steps that runs things very well. So if it's a good quality inverter you might be okay, again, check it with your equipment.

 

[Life In The Dog House]

Hi Robaroni,

Thanks for the information.

Is it possible to test the modified sine wave inverter I have now, by simply hooking it up to one of the batteries and see if there is a hum when I plug stuff into it i.e.) cell phone, laptop etc. ?

I don't use a toaster or anything heavy. Although, I do hope to be able to use my small instapot (700 watts) once or twice a week after the system is installed.

 

[robaroni]

I would say do it one piece of equipment at a time. The other thing to look for is adding heavy loads with sensitive electronics also hooked to the inverter.
Trace engineering became Xantrex and it was the gold standard at the time, noted for being very robust and well made. My thinking is that it's probably going to do fine for you.

Hook it up with something you won't miss, not that it will destroy it as I doubt that will happen. A old laptop or LCD monitor should be a good test. Usually you'll see lines or bars in a monitor or laptop if it's struggling with the power source. An audio amplifier will likely show up hums too, CD players with earbuds, things like that are good tests especially if you can try them with different wall transformers.

 

[Life In The Dog House]

Awesome. Thank you robaroni! I am totally out of my scope of knowledge with this. I will give it a try this afternoon and see how it goes.

Thanks again!

 

[robaroni]

No problem, glad to help.

 

[Life In The Dog House]

Hi everyone,

I quickly hooked the Xantrex 1000 (2000 peak) watt modified sine wave inverter up to one of my batteries. I don't have much in my van to plug in, so I did my laptop, and a few other things i.e.) small tablet etc. Everything seemed to work fine; I did not any hums, or lines in my laptop screen, etc. The only thing I noticed was that the inverter fan kicked in immediately with my laptop plugged in.

Looking at the inverter box (in the daylight, and not at 11pm at night) it does state that it is mobile power for trucks, RV's Boats & Vans; and is good for: compact microwaves, food processors to VCR's, satellite equipment, computer systems with 17" monitors, etc.

So I am thinking, I am good to go with this one; and may be able to use my little Instapot with it. If I am mistaken, please let me know!




b.james, svetz & robaroni- thanks again for all your input! It is very much appreciated!!

 

[eddie1261]

Right now I am living on savings which are quickly dwindling while getting ready to launch a new business, so I really need to make my dollars stretch.

Craigslist have anything? Anything on the for sale area here that fills the bill? It doesn't all have to be new, especially while you are counting your coin jar to fund this. Get it running now and replace when you have money.

 

[Life In The Dog House]

Hi eddie1261,

Unfortunately, I live on an island and the hefty ferry round-trip ferry ticket for the van is more than I want to spend right now. Not to mention that a trip off island is an all-day affair. I am trying to launch the business by Columbus Day weekend...time is running short

 

[eddie1261]

Can't you get stuff shipped to you on your island? Is it one of those islands like in cartoons where it's like one guy and a palm tree?



I mean, eventually they even found Gilligan..... It sounds like that business should be a competing ferry line!

 

[Life In The Dog House]

LOL...no...Amazon ships here. There is only one ferry that brings vehicles to the island, and they a monopoly on it...hard to explain, as most of us don't get it...they are a quazi public entity and a private enterprise at the same time, and accountable to no one but themselves.

 

[Supervstech]

Hi eddie1261,

Unfortunately, I live on an island and the hefty ferry round-trip ferry ticket for the van is more than I want to spend right now. Not to mention that a trip off island is an all-day affair. I am trying to launch the business by Columbus Day weekend...time is running short

I hope it is a great paradise island(mmmm amazons)
Anyway, I better cage my comic book nerd...

I got lucky and found a 1200watt PSW inverter free when I bought some van shelves a few months back. Craigslist is a wonderful thing. Sorry it’s notan option for ya.
I have used MSW inverters for years, running vcrs, computers, laptops, power tools, battery chargers, etc... never had any issues, but I didn’t know any better at the time... now that I do, I fear being smacked for laziness...

It’s a shame, since I have a 5kw MSW, a 3kw, several 2kw, and a few smaller units in my vehicles... and now I’m afraid to use them for fear gremlins will destroy my tools...

Anybody want some lightly use modified sign wave inverters?

 

[Life In The Dog House]

It is an island thing....no chain businesses i.e.) No Walmart, McDonald's, everything is mom and pop owned. Max speed limit is 45mph. I can walk the dog at 3am and only have to fear skunks...you do have to pay a price to live in paradise

 

[gnubie]

A word of warning when it comes to modified sine wave (modified in the same way that a bicycle is a modified car). Active power factor correction is making its way into even new cheapo devices. Active PFC uses a pre-converter that spreads out the normally high crest load of a standard switching power supply so that it draws current across the entire waveform. This can turn a poor power factor of .7 into .95 and higher.

Active PFC chips may not handle the stepped wave of a modified sine inverter at all well. The better chips have specific provision for it and will cope. The cheapie ones may trip up when hit with the stepped wave and not supply enough current to the actual power supply causing it to tick or buzz but provide no DC output. I've directly seen an unidentifiable PFC chip go bang and let the smoke out when faced with modified sine wave.

My greatwall manufactured Corsair PC power supply uses one of the cheapie PFC chips and only makes a 100Hz tick instead of starting.

 

[eddie1261]

It is an island thing....no chain businesses i.e.) No Walmart, McDonald's, everything is mom and pop owned. Max speed limit is 45mph. I can walk the dog at 3am and only have to fear skunks...you do have to pay a price to live in paradise

Where are you? Key West?

 

[Life In The Dog House]

@ eddie1261

No...off the coast of Massachusetts.