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Questions of supported AMPs of inverter's AC output

kyuan

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Nov 30, 2020
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Hi experts,
I am planning to have solar + lithium battery + inverter for my RV and trying to dig some technical details about the inverter.
What I plan to buy is GoWISE Power PS1004, it runs continuously 3kw and peak at 6kw, according to the spec. What concerns me is, the AC outlet of this inverter ( in fact most of inverters) are NEMA 5-15 socket, which support up to 15A. A simple math 120*15 = 1800W only.

Questions:

1, how can I continuously run 3KW from it, with each outlet limited at 15A?
2, Most of 2kw/3kw inverters comes with 2 or 3 AC outlet. Is AC from those outlets ( on a single inverter ) has the same phase so I can combine 2 or 3 AC outputs into 1, to exceed 15AMP limitation?

Thanks!
 
I'll be perfectly honest. I think inverters like this are a scam, and will never under real-world conditions produce 3000W. Why, amperage. Just do the math. 3000W/12V = 250amps. How long do you think a battery is going to last when trying to pull 250A from it? Just look at the cabling supplied with the unit. I would guess that it can't be greater than 4 gauge or so from the way it's coiled. 250A through a 4 gauge wire, I don't think so.

The first thing to check is if it is UL listed? At the Underwriter's Laboratory, they will actually test the unit to determine if it is safe to use as intended. I seriously doubt that a unit that has to draw that much current is going to pass their safety checks?

Does the unit actually work? Well, if you plugged in your TV, or a reading lamp, then sure, it will work. It might even power a 1000W toaster. But three toasters at the same time? I don't think it will happen.

If you want to run your TV, or stereo, or maybe a little 1-cup coffee maker, then it might be OK. Don't even try to actually pull 3000W out of it. Something might catch on fire.

To actually produce 3000W you need a serious 24 or 48V inverter. With my own system, I have actually observed about 3600W of output. That was with my 240V well-pump running, and the wife ironing clothes in the house. But, I have a 48V inverter with a 400Ah battery.
 

With each socket intended for max 15A, 1800W, three sockets could carry 5400W.
So the sockets at least can handle a total of 3000W continuous and 6000W surge.
Plug in two, 1500W or 3, 1000W loads and try it out.

The comments on the Amazon page had mixed reviews. Here's the first one:

"Question:
Is the specs on this inverter true, tested pure sine wave capable of 3000w cont/6000w peak? Due to pricing seems to good to be true and over-rated.
Answer:
As a contractor I purchased one of these hopeing to run some power hand tools as well as recharge batteries for my cordless tools. The first tool I tried was a 15amp circular saw, popped the breaker as soon as I pulled the trigger. I returned it and purchased a 3000 watt from the invertor store, it works fine, however the price is double. So to answer your question yes the price is too good to be true."
https://www.amazon.com/GoWISE-Power-PS1004-Pure-Inverter/dp/B0131PZ9J2#
 
I'll be perfectly honest. I think inverters like this are a scam, and will never under real-world conditions produce 3000W. Why, amperage. Just do the math. 3000W/12V = 250amps. How long do you think a battery is going to last when trying to pull 250A from it? Just look at the cabling supplied with the unit. I would guess that it can't be greater than 4 gauge or so from the way it's coiled. 250A through a 4 gauge wire, I don't think so.

The first thing to check is if it is UL listed? At the Underwriter's Laboratory, they will actually test the unit to determine if it is safe to use as intended. I seriously doubt that a unit that has to draw that much current is going to pass their safety checks?

Does the unit actually work? Well, if you plugged in your TV, or a reading lamp, then sure, it will work. It might even power a 1000W toaster. But three toasters at the same time? I don't think it will happen.

If you want to run your TV, or stereo, or maybe a little 1-cup coffee maker, then it might be OK. Don't even try to actually pull 3000W out of it. Something might catch on fire.

To actually produce 3000W you need a serious 24 or 48V inverter. With my own system, I have actually observed about 3600W of output. That was with my 240V well-pump running, and the wife ironing clothes in the house. But, I have a 48V inverter with a 400Ah battery.
Thanks Michael, looks like I need to lower down my expectation again.
 
With each socket intended for max 15A, 1800W, three sockets could carry 5400W.
So the sockets at least can handle a total of 3000W continuous and 6000W surge.
Plug in two, 1500W or 3, 1000W loads and try it out.
This is my interested part. If AC on three sockets are on the same phase then I can combine 3 plug into 1 and trying to get 3000w since each can carry 1000W. I may need an oscilloscope to check the phase first. Anyone did that before?


The comments on the Amazon page had mixed reviews. Here's the first one:

"Question:
Is the specs on this inverter true, tested pure sine wave capable of 3000w cont/6000w peak? Due to pricing seems to good to be true and over-rated.
Answer:
As a contractor I purchased one of these hopeing to run some power hand tools as well as recharge batteries for my cordless tools. The first tool I tried was a 15amp circular saw, popped the breaker as soon as I pulled the trigger. I returned it and purchased a 3000 watt from the invertor store, it works fine, however the price is double. So to answer your question yes the price is too good to be true."
https://www.amazon.com/GoWISE-Power-PS1004-Pure-Inverter/dp/B0131PZ9J2#

I also noticed this review. Seems like worth a try..
 
They're going to be in phase. Just 3 outlets connected to one wire.
If you use three plugs, one concern is whether current splits evenly. If not, a wire could overheat.
Another, if you unplug one the pins are electrically hot.

If I was going to do that, I would open it up and wire with 10 awg.

Note that the output is possibly two 60V hots, 120V apart, rather than having a proper neutral.

All depends on your application. House? Van? Portable?
You can buy other units, more money and better. You can buy used.
Something that is important is whether it can start your loads. Motors often require 5 times their nameplate rating. This one may run a refrigerator but not a water pump, or instance.
 
They're going to be in phase. Just 3 outlets connected to one wire.
If you use three plugs, one concern is whether current splits evenly. If not, a wire could overheat.
Another, if you unplug one the pins are electrically hot.

If I was going to do that, I would open it up and wire with 10 awg.

Note that the output is possibly two 60V hots, 120V apart, rather than having a proper neutral.

All depends on your application. House? Van? Portable?
You can buy other units, more money and better. You can buy used.
Something that is important is whether it can start your loads. Motors often require 5 times their nameplate rating. This one may run a refrigerator but not a water pump, or instance.
Thanks Hedges!
"If I was going to do that, I would open it up and wire with 10 awg." --> I am just trying not to invalid the warranty, :)

"All depends on your application. House? Van? Portable?" --> It's on a RV to make it always have 120V without running generator.
 
You need an inverter that specifically allows for hard wiring the inverter to a subpanel. My older 1000w Xantrex MSW inverter allows just that. But knowing that it only provides 1000w, I wired up a single remote output to provide power to my coffee maker.

An inverter that only has outlets on the inverter and no support for hard wiring, is not an inverter I would be using in my RV unless it was to be used for isolated devices.
 
This is my interested part. If AC on three sockets are on the same phase then I can combine 3 plug into 1 and trying to get 3000w since each can carry 1000W. I may need an oscilloscope to check the phase first. Anyone did that before?
.

What you are talking about is jury-rigging an already marginal inverter to squeeze maximal power out of it? I really can't imagine that ending well! I think you are just asking for trouble. Spend the $ to do it right the first time. Just bite the bullet and spend the extra $ on a quality inverter that won't let you down. Stick with the 2X rule. If you really need 3000W, then buy a 6000W inverter. Buy at least a 24V Magnum, or Outback, or Schneider, or Vitron. You'll remember the quality long after the price is forgotten. And you're likely to sleep better with no acrid smoke in the air.
 
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