Go Power inverters?

[BradKW]

I need pure sine for my computer, possibly for a couple other minor things. 

I need enough power to run a 5k btu window AC, possibly experimenting with a 110v fridge, and hand tools.

The Magnum line which I was planning on getting prices me out of the game for something of that size, so looking at other options.

The Go Power! GP-SW3000-12 3000-Watt Pure Sine Wave Inverter looks like a good mix of price and performance, but all I have to go on is Amazon reviews. They are generally very positive and I keep seeing praise for the customer service... anyone here have experience with this brand?  It bothers me that it's so much cheaper than a comparable Magnum but I don't know enough to understand why...

https://www.amazon.com/Go-Power-GP-SW3000-12-3000-Watt-Inverter/dp/B0015353XU/ref=cm_cd_al_qh_dp_t

In the DIY 'fridge thread, I keep seeing efficiency rating for the inverters talked about, as well as passive draw...how do you find this information when shopping?

Thanks!

 

[jimindenver]

I have no real experience with this inverter but I'd look for why people complained, what kind of after purchase support there is and is it a disposable product. I would look for reviews on rv, solar, offgrid, boating forums and you tube. Someone has taken it apart.

I would also make sure it is designed to handle starting the tools and compressor. My cheap 3000w PSW inverter ran a microwave, coffee pot, hair dryer, cook top and more for a season. Even though mine failed I'd still suggest it if that was all you were going to do with it. That said, it wasn't designed to start motors, even one rated for less than a sixth of its running wattage, a 12th of its peak. That's why I went industrial when I replaced it. I know it will be starting motors and its transformer can start that A/C over and over.

You may see 3000w/6000w peak but that peak may be micro seconds and you may not even get to run it at 3000w for long. They can really fudge with the ratings and get away with it with a lot of things.

Last thing is from going to various forums I have seen it said that there is a limit of how big of a inverter that you SHOULD run at 12v. In this case getting the amperage needed to support 3000w at 12v requires not only huge wires from the bank but internally too. A bank that could support it would be enormous. At those wattage it is just more efficient to go with a higher voltage bank.

 

[akrvbob]

My only exprience with Go-Power was a cheap 300 watt MSW inverter. By far the worst one I've ever owned. The fan was incredibly loud and never went off--not once. Until it failed after 54 weeks. Then it went in the trash--good riddance.

It's probably totally unfair to draw any comparison between the 3000 and the the 300, but I won't be doing business with them again.

Any decent manufacturer will have a specs list on-line for its products so go to the one for the inverter and you are looking at and look for something that sounds like "no-load draw". The wording may be different, but it will be something like that. .2 amp per hour is good, but the PSW do more so work harder so .5 amps would be okay. 1 amp would be pretty high--that's 24 amps wasted every day.
Bob

 

[BradKW]

Any decent manufacturer will have a specs list on-line for its products so go to the one for the inverter and you are looking at and look for something that sounds like "no-load draw". The wording may be different, but it will be something like that. .2 amp per hour is good, but the PSW do more so work harder so .5 amps would be okay. 1 amp would be pretty high--that's 24 amps wasted every day.
Bob

Could you take a look at this spec sheet (it's a .pdf)? http://ecx.images-amazon.com/images/I/71IVSl6kYlS.pdf

It states under a category named "No Load Current Draw/Powersave" : 2 A / 0.55 A

I read that to say when it's doing nothing, it draws 2 amps, and when it's REALLY doing nothing, it's only 0.55 amps. Unfortunately, that doesn't make much sense to me...

 

[akrvbob]

It states under a category named "No Load Current Draw/Powersave"  :  2 A / 0.55 A

I read that to say when it's doing nothing, it draws 2 amps, and when it's REALLY doing nothing, it's only 0.55 amps.  Unfortunately, that doesn't make much sense to me...

I've never seen one like that either. The .55 amps is good for a big PSW, no problem there, but I have no idea what the 2 amp refers too but that is NOT okay. Unless you are only going to have it on briefly each day, that's going to take big bite out of your bank.

Give em a call or email and ask what that means. Their response will  tell you sommthing right there.
Bob

 

[SternWake]

Most inverters have a significant standby draw, turned on powering nothing, but some of them have the 'powersave' option where when they sense no power being drawn can lower the standby current.

i am not sure how they know when the residential compressor fridge, or a window shaker AC decides to cycle on, and they need to cover that load. I do not know how this inverter works, in this regard, very short on details.

I've never owned an inverter this size, and do not really know much about them.
A 2 amp load continuously, even when powering nothing, would not be acceptable to me. as that would consume more than 2x the average draw of my fridge in an hour, all for nothing.

My 800 watt MSW inverter has a standby load of 0.68 amps
My PSW 400 watt inverter has a standby load of 0.24 amps.

I rarely use either, but they are necessary to have.

Do consider a dedicated inverter for your AC, like Jim in Denver uses a tripplight industrial 1250 watt for his AC.

You could use a much smaller Pure sine wave inverter just for those items that might really need it, like your macbook.

the two inverter method might seem more complicated, but can actually save power, and money, as one does not need 0000 cable for a 1250 watt inverter and a 300 amp speciality fuse.

Also the standby currents of smaller inverters are generally smaller too.

A 3000 watt inverter powering a 90 watt laptop might consume 3x as much electricity as a 300 watt PSW inverter powering the same laptop. The 3000 watt version might have an annoying loud fan, the 300 watt PSW version the fan might never come on powering just the laptop. When the AC compressor kicks on, while the laptop is being powered, there might be a small period of time where voltage sags, or the waveform is no longer pure sine. If there are separate inverters the large cycling load would not affect the smaller inverter powering delicate electronics.

Anyway, strategies to consider, One big inverter for the huge loads, one smaller PSW inverter for the smaller loads.
Lots of 'coulds' and 'mights' in the above paragraph. They might be totally discountable, or not, I do not know.


Kind of some redundancy too. If you have one 3K inverter, and it fails, then you can't power your laptop either. One smaller dedicated AirCon inverter and one smaller PSW inverter for finicky electronics, if one fails you have the other until you can replace the failed unit.

 

[BradKW]

Do consider a dedicated inverter for your AC, like Jim in Denver uses a tripplight industrial 1250 watt for his AC.

You could use a much smaller Pure sine wave inverter just for those items that might really need it, like your macbook.

the two inverter method might seem more complicated, but can actually save power, and money, as one does not need 0000 cable for a 1250 watt inverter and a 300 amp speciality fuse.

That's a good point, and indeed is a approach I gave some thought to. Probably not as much thought as it deserves really...it seemed too complicated and I had too many unknowns. When I decided I wanted to experiment with a 120v refrigerator, I lost patience trying to parse what my true needs will be and jumped to wanting a 3000W pure sine.

I should probably take a step back and think it through again when I feel rested.