inverter power consumption

[defed]

i've been looking at inverters.  i would like a pure sine, so was looking at the xantrex prosine, since i have a xantrex controller.

it says it uses 22w when on, and 1.5w idle.  i believe it only goes 'idle' when the load on it is under 20w...so in my case, it wouldn't go to idle.  so that's 528w consumed in 24hrs, just to be operating...seems like an awful lot.  i haven't had much luck finding a simple chart w/ inverter power usages, and it's impossible to go thru every inverter made reading the specs...i'm just curious if this is a typical figure, on the high side, etc.

if anyone has an inverter to suggest, i need 24v, UL listed, hardwire-able to transfer switch, chassis ground separate (not tied to negative), around 1000w is sufficient.

thanks.

[Volvo farmer]

That's about par for the course.  Both Outback and Magnum are about 20-25W idle, less in "search".

Most folks just figure the extra into their array and be done with it. You need about 100 watts of panel to cover inverter idle losses and at today's prices, that's only about $200.

If you are going to seriously be playing with RE for a while, I might suggest you get a nice 3-4 KW inverter. It would likely be the last inverter you would ever buy. I see those 1000-1500 watt units come up for sale used all the time because their owner finds the need for more power.

Personally, when I researched the history of the Xantrex company, I did my best to spend money with the boys in the Pacific Northwest.  The product lines and prices are similar between all the  major players and I think you only have about three choices if you get up into the 3-4KW range at 24V.

[defed]

thanks for the info.  i don't recall why i picked xantrex over outback, and i don't NEED to stay w/ xantrex for the inverter.

my whole house usage is only 5-7kwh/day.  my largest loads, electric oven and well pump will probably never go on the inverter.  and if increase my solar production again (at approximately 1700w now), i will probably grid tie, which means a new inverter anyway (and possibly go to 48v).  at this time, at most, i will have 300w demand at one time, with no start up draws to figure in, so i thought a 1000w would be alot more efficient than running a 3000w inverter at such a low level.

[mab]

Do you really need pure sine?

Most things cope OK with MSW, and MSW tend to have a lower draw at idle (I think); My APC 1400VA UPS draws about 0.75A at 24v, and I doubt it was designed for no-load efficiency.

m

[defed]

i don't know that i absolutely need a pure sine, but i would be running computers, tv's, etc.  figured pure was the safest way to go.

the xantrex has a 1.5w draw with no load, and 22w draw while powering loads.  i think it was if the load was under 20w, it went into 1.5w mode.  unfortunately, my 24hr loads are about 40w.

[freejuice]

FWIW,
 I have an outback grid tied ( GTFX3048)   if not mistaken, info says it uses 20 watts idle.
I love the thing....cant stop staring at it.

 Side note:
Outbacks have some nice extra features especially when combined with the Mate.

Since I dont need to chage the default settings , but would like to know the KW's produced from the wind generator, I'm going to hook up a standard house meter and socket to see the KWs produced....about 35 bucks

[ChrisOlson]

i've been looking at inverters.  i would like a pure sine, so was looking at the xantrex prosine, since i have a xantrex controller.

Isn't the ProSine line designed for RV and Marine use with a floating neutral?  Xantrex's XW residential grid-tied and off-grid inverters are built by Schneider Electric and they're pretty much the gold standard.  We got two of them in our home (stacked 120/240 volt, 8 kva) and love their performance, quiet running, and efficiency.

Most folks buy the Outback units because they're half the price.  But make sure that what you're looking at is designed for residential use because mobile or portable units typically use the "floating" neutral, which is required for applications like RV's and boats, but doesn't meet electrical codes for residential use.
--
Chris

[birdhouse]

defed-
i've got a 24v xantrex 1800w pure sine.  love it!  got it used on flea-bay for $500US.  kinda a gamble to buy used, but i think i got a good one.  it has been a lot of bang for my buck, and i'd recommend it to anyone needing a moderately/small sized inverter. 

it'll run my pancake air compressor, circular saw, chop saw, portable table saw, and welder, though just for tacking.  it shuts down if i try to lay a bead with my millermatic 135. 

i don't think the prosine 1800's have the 60/60v split power.  you can bond the case with no issue.  manual recommends it. 

adam

[defed]

Isn't the ProSine line designed for RV and Marine use with a floating neutral?  Xantrex's XW residential grid-tied and off-grid inverters are built by Schneider Electric and they're pretty much the gold standard.  We got two of them in our home (stacked 120/240 volt, 8 kva) and love their performance, quiet running, and efficiency.

Most folks buy the Outback units because they're half the price.  But make sure that what you're looking at is designed for residential use because mobile or portable units typically use the "floating" neutral, which is required for applications like RV's and boats, but doesn't meet electrical codes for residential use.
--
Chris

i was reading the prosine manual, it seems to indicate that the chassis has its own ground terminal...which i presumed meant it was separate from the negative.  i need to look at it again.  i do seem to recall that they do show wiring for RV, marine and residential applications.  i'll check into the XW ones too...seems i have missed those.

Birdhouse,

which model do you have?  an 1800 prosine or XW?

[DanG]

Remember non-search idle losses are always there - there is still that 25 watt overhead at 10% or 90% power...

Best may be shut off inverter and use direct DC for incidentals, 40 watts of compact fluorescents with 10% line losses is just 4 watts.

[ChrisOlson]

i was reading the prosine manual, it seems to indicate that the chassis has its own ground terminal...which i presumed meant it was separate from the negative.  i need to look at it again.  i do seem to recall that they do show wiring for RV, marine and residential applications.  i'll check into the XW ones too...seems i have missed those.

Well, even the mobile ones with floating neutral have a chassis ground lug that is bonded to the vehicle frame.  The best way to make sure is to have somebody that has one measure the voltage from both the flat blades to the ground in one of the plugs.  If they both got power then it has a floating neutral.  I am not familiar with the ProSine series, but typically mobile units are designed this way because you can accidentally come in contact with the "hot" conductor and won't get a shock because the ground is not bonded to the neutral.

EcoDirect has good prices on XW-series inverters:
http://www.ecodirect.com/Xantrex-XW4024-p/xantrex-xw4024.htm

--
Chris

[boB]

Inverters for RV and marine usage will usually have a relay switched neutral to ground connection.

The relay will un-bond the neutral/gnd connection when it is connected to shore power and connect
the two together when operating as an inverter because then, the inverter is the power source.

Otherwise, the generator or shore power is the source and the bond is done there.

The UL spec usually followed for these types of inverters is  is UL458,

"Power Converters/Inverters and Power Converter/Inverter Systems for Land Vehicles and Marine Crafts"

boB

[WindriderNM]

I have used a MSW for several years it runs my computers, tv, Wildblue internet, router, dish DVR, and small swamp cooler. I can't run ac, refrigerator, or well pump with it.

I have a timer switch that turns most thing off when I'm not home and at night. A lot of things still use power when off.

[defed]

I have a timer switch that turns most thing off when I'm not home and at night. A lot of things still use power when off.

right, i stated earlier that i have a constant 40w draw, minimum.  some things i need to leave power to at all times, ie clock radio/alarm, cordless phone receiver, dvr/vcr w/ record timers...i kill whatever i can w/ power strips when not in use, but some things must stay on.

[defed]

Well, even the mobile ones with floating neutral have a chassis ground lug that is bonded to the vehicle frame.  The best way to make sure is to have somebody that has one measure the voltage from both the flat blades to the ground in one of the plugs.  If they both got power then it has a floating neutral.  I am not familiar with the ProSine series, but typically mobile units are designed this way because you can accidentally come in contact with the "hot" conductor and won't get a shock because the ground is not bonded to the neutral.

EcoDirect has good prices on XW-series inverters:
http://www.ecodirect.com/Xantrex-XW4024-p/xantrex-xw4024.htm

--
Chris

ok. i'll check into more closely.  not sure if the hardwired ones are any different than the ones w/ AC receptacles on them or not...i'd imagine they are the same.

[ChrisOlson]

defed,
I think they're the same.  I was curious about this after reading boB's post, so I downloaded the manual for the ProSine 1800.  On page 54 it says:

The PROsine provides an installer-defeatable system that automatically connects the neutral conductor of the inverter AC output circuit to safety ground (“bonding” it) during inverter operation, and disconnects it (“un-bonding” it) when the PROsine has connected to AC shorepower. This system is designed to conform to installation codes that require single-phase AC sources such as inverters and generators to have their neutral conductors tied to ground

That actually looks like a nice inverter.  But it doesn't look like they recommend it for residential prime power.  It says in the manual that it is suitable for marine, recreational vehicles, commercial vehicles and residential back-up power.  They have a diagram in the manual for hooking it up for residential backup power with a sub-panel.
--
Chris

[ChrisOlson]

right, i stated earlier that i have a constant 40w draw, minimum.  some things i need to leave power to at all times, ie clock radio/alarm, cordless phone receiver, dvr/vcr w/ record timers...i kill whatever i can w/ power strips when not in use, but some things must stay on.

At 40 watts constant draw (what the hell kind of electronic stuff you got that has that kind of parasitic power consumption anyhow??) why are you even worrying about idle power consumption?  It's a non-issue once you put a load on the inverter.

With no load an inverter is zero percent efficient.  That means it consumes power without doing a damn thing except consuming power.  Once you get to 40 watts or so you're right in the peak of the power efficiency curve of most inverters.  If you were like most of us who live off-grid you'll get rid of the 40 watts of "stuff" running all the time so the inverter goes into search mode unless the fridge or freezer starts up and brings it out of search.  To burn off .96 kWh per day just so you can have clocks and timers going in electronic movie recording gadgets is unthinkable to me.  I'd throw the power sucking thing in the driveway and run over it a few times with the Dodge Cummins to "cure" its power wasting problem.
--
Chris

[rossw]

At 40 watts constant draw (what the hell kind of electronic stuff you got that has that kind of parasitic power consumption anyhow??)

...

To burn off * kWh per day just so you can have clocks and timers going in electronic movie recording gadgets is unthinkable to me.  I'd throw the power sucking thing in the driveway and run over it a few times

I'm not the original poster, but perhaps you can think beyond your own fence for a moment.

Some of us cannot get a basic telephone (for example).... and have to actually run it over (shock horror) wireless links and the internet. We could burn 300 or 400 watts on a "decent" installation and "justify" running the inverter I suppose - but instead we run flea-power radio links that take about 4-5 watts, and ATA (analog telephone adaptors) that take about the same again (one for each two lines). 

In my case, I also run another link out to my neighbour who also doesn't have the "luxury" of a phone line and piggybacks off mine.

I also am required (by law, because of my location) to treat all wastewater (grey and black) - which requires airation (pumps and things, including timers) - probably only a few watts for the basic electronics, more when the pumps are running), and overheads for pressure pumps, smoke detectors etc. (many of which are mandated by law where I am and may be in other parts of the world)

[ChrisOlson]

I'm not the original poster, but perhaps you can think beyond your own fence for a moment.

Well, I can sort of see stuff like that.  We have cattle and have to pump water for them all the time too.  But I think in this case we're talking about parasitic draw from entertainment equipment.  Our Toshiba big screen TV set draws 28 watts just sitting there waiting for a signal from the remote, as an example.  We have a small TV set in our bedroom that draws 9 watts waiting for a signal from the remote.  We, of course shut those off so we're not running 37 watts worth of TV sets that aren't even being used.

The search mode watts in our Xantrex inverters can be set in 8 watt increments.  The inverters won't go into search mode on the 8 watt setting because of the GFI outlets in our bathroom and on our sump pump in the basement.  On the 16 watt setting the inverters will go into search mode and then they only draw 7 watts of power putting pulses thru the line looking for a load.  But that search mode draw is only important if you got your energy consumption down to where it actually works.

I read back thru the thread and I wrongly assumed defed was off-grid, but it looks like he has grid power.  People who have grid power don't usually think about that stuff so the 40 watts continuous draw is nothing.  But off-grid, that .96 kWh that gets consumed in a day is enough to run our freezer for one whole day.

According to the Consumer Guide to Home Energy Savings, these parasitic loads cost the average US household $88 per year.  The amount of power wasted in the average US home in a year by these devices that stay "hot" when they're turned off would power our home for a whole month in the middle of winter when our power consumption is the highest.
--
Chris

[ruddycrazy]

Well when I was researching for an inverter for my shed I was using my 24 volt SA32 Selectronics inverter spec's to compare with. I came across a Kipoint KI-3000 3kw pure sinewave with a 4 watt typical idle power draw. This inverter came within 99% of the selectronic spec's but without the lcd and the smart management system. Also the price tag was 2/3's off the selectronic. This inverter has been going strong for over 5 years now and powers everything apart from my 3 hp aircon and my Lincoln caddy welder. I run 2 and 3 hp VFD's to run my lathes and Bridgeport milling machine.

Cheers Bryan
 

[defed]

At 40 watts constant draw (what the hell kind of electronic stuff you got that has that kind of parasitic power consumption anyhow??) why are you even worrying about idle power consumption?  It's a non-issue once you put a load on the inverter.

With no load an inverter is zero percent efficient.  That means it consumes power without doing a damn thing except consuming power.  Once you get to 40 watts or so you're right in the peak of the power efficiency curve of most inverters.  If you were like most of us who live off-grid you'll get rid of the 40 watts of "stuff" running all the time so the inverter goes into search mode unless the fridge or freezer starts up and brings it out of search.  To burn off .96 kWh per day just so you can have clocks and timers going in electronic movie recording gadgets is unthinkable to me.  I'd throw the power sucking thing in the driveway and run over it a few times with the Dodge Cummins to "cure" its power wasting problem.
--
Chris

i am on grid, and before i began this RE 'hobby', my daily usage was 8kwh/day.  i put a kill-a-watt meter on everything i own, got rid of some CRAZY power hogs, got a new fridge (should pay for itself in 4 yrs), etc.  i am currently down to 5-6kwh/day.  i think that's pretty good no matter how i'm powering, as i don't really THINK about conserving, so i'm not doing w/o anything.

the list of parasite draws is as follows:

phone:  2w
clock radio:  1w
dvr:  5w
vcr:  3w
dish receiver:  10w
OTA tuner:  5w
tv:  1w
cable modem:  5w
router:  5w

that's 888wh/d.  do they all have to be on all the time?  most do, as they lose their dang memory when w/o power for more than a few mins.  seems kind of ridiculous that my PC doesn't forget everything when completely unplugged, but my dvr and dish go blank when the power goes out for 10 mins.

as you say, if i HAD to rely on my RE for all my power, this would probably be insane.  but at 12 cents a kwh, it's convenient.

[rossw]

According to the Consumer Guide to Home Energy Savings, these parasitic loads cost the average US household $88 per year.  The amount of power wasted in the average US home in a year

There was a move - I thought internationally - to mandate that all equipment with a "standby" mode had to draw less than 3 watts, and less than 1 watt by 2015 (??).

Your TV taking 28W in standby sounds to me like it's a digital TV/PVR type thing that is actually running much more than just the "waiting for a wakeup signal".

As for wasted power - it irritates me every time I go virtually anywhere and see the amount of WASTED power. Hell, even just driving down the road and seeing the odd street light on in the middle of the day... ONE of those things running all day is close to my daily power demand...!

[defed]

defed,
I think they're the same.  I was curious about this after reading boB's post, so I downloaded the manual for the ProSine 1800.  On page 54 it says:

The PROsine provides an installer-defeatable system that automatically connects the neutral conductor of the inverter AC output circuit to safety ground (“bonding” it) during inverter operation, and disconnects it (“un-bonding” it) when the PROsine has connected to AC shorepower. This system is designed to conform to installation codes that require single-phase AC sources such as inverters and generators to have their neutral conductors tied to ground

That actually looks like a nice inverter.  But it doesn't look like they recommend it for residential prime power.  It says in the manual that it is suitable for marine, recreational vehicles, commercial vehicles and residential back-up power.  They have a diagram in the manual for hooking it up for residential backup power with a sub-panel.
--
Chris

that's the way i had read it, but i'm not an expert on electrical, so sometimes what i think it says it not what it really meant.

since this is just a hobby (an expensive one at that), i had planned on running the inverter to a transfer switch, which i could control what loads the RE is powering.  basically a backup configuration in reverse.  if batteries get low, i can switch back to grid, if i have too much power, i can add more loads.

[Volvo farmer]

I find it hard to put myself in your shoes, because on the one hand, you say this is a hobby, but on the other hand, you seem to be willing to spend a lot to do it right.  I don't know what your eventual goal here is, but I just wonder if you wouldn't be ahead in the long run just to design a grid-tied battery backup system.

As for parasitic loads. There are alarm clocks out there that will run for a couple years on a set of AA batteries.  A dish receiver will find all the satellites and download the guide in about 5 minutes if you completely power it off. We have been using ours for years like that. However, a DVR is a different story. I would love to have one, but am unwilling to put up with the 24/7 power consumption.  Also, when we had an OTA tuner, we were able to power it down and it retained it's channel memory.  I know this stuff doesn't cost you much to run and I am thinking about it like an off-grid person.  I just thought I'd share my experience with "parasitic" loads.

[WindriderNM]

I found that I mostly record shows in the evening so my Dish DVR is timed to come on at 4:50 pm until 12:00 pm. My timers run on AA batteries that last years. With a power strip switch my dish receiver still make a humming noise on my old  MSW inverter. The DVR seams to use about 60 w either on or off.

[SteveCH]

There is a lot of info' floating about regarding Modified and Pure sine wave inverters. I am not a technician, nor an expert in any sense of the word.

I just switched us to a new Outback VFX inverter [which is "pure" sine wave] after using a Trace [Xantrex] modified sine wave inverter to power the ac loads in our house for well over 20 years. My wife works from home, with computer stuff, and our computer equipment includes five computers, three flat-screen monitors, late-model laptops, printer, etc. In addition, we have the usual collection of vacuum cleaner, clothes washer, Vizio flat-screen tv and etc etc.

In all these years, we have had zero problems with modified sine wave. I do not discount those who advise to stay away from such inverters. All I can say is, in our experience, no trouble of any type I've ever witnessed. The only reason I switched to the Outback is that I have gone to a different battery chemistry which I anticipated the Trace would have trouble with. The input voltage allowed for the Outback is higher than that listed for the Trace....

I understand, from forums such as this one, that Xantrex [formerly Trace] is now having its equipment either manufactured or whatever overseas [read: China??]. I do not know that for certain, just what I've read. Whether the quality has decreased due to this, I have no experience to say one way or the other. Just something for you to check out.

[defed]

I just wonder if you wouldn't be ahead in the long run just to design a grid-tied battery backup system.

that's what i am doing (or trying to do)...i just don't want to go thru the hassle of the power co and the cost of the grid tie inverter right now.  i hope to have a 'grid tie ready' system, when i have the $ to get the right inverter and time to get the power co involved.

[defed]

i appreciate all of the discussion we have going here.

[fabricator]

There is a lot of info' floating about regarding Modified and Pure sine wave inverters. I am not a technician, nor an expert in any sense of the word.

I just switched us to a new Outback VFX inverter [which is "pure" sine wave] after using a Trace [Xantrex] modified sine wave inverter to power the ac loads in our house for well over 20 years. My wife works from home, with computer stuff, and our computer equipment includes five computers, three flat-screen monitors, late-model laptops, printer, etc. In addition, we have the usual collection of vacuum cleaner, clothes washer, Vizio flat-screen tv and etc etc.

In all these years, we have had zero problems with modified sine wave. I do not discount those who advise to stay away from such inverters. All I can say is, in our experience, no trouble of any type I've ever witnessed. The only reason I switched to the Outback is that I have gone to a different battery chemistry which I anticipated the Trace would have trouble with. The input voltage allowed for the Outback is higher than that listed for the Trace....

I understand, from forums such as this one, that Xantrex [formerly Trace] is now having its equipment either manufactured or whatever overseas [read: China??]. I do not know that for certain, just what I've read. Whether the quality has decreased due to this, I have no experience to say one way or the other. Just something for you to check out.

Schneider has made a huge investment in updating hardware and software since they bought Xantrex, from all the reviews I've read Xantrex is state of the art in every respect.

[defed]

There was a move - I thought internationally - to mandate that all equipment with a "standby" mode had to draw less than 3 watts, and less than 1 watt by 2015 (??).

Your TV taking 28W in standby sounds to me like it's a digital TV/PVR type thing that is actually running much more than just the "waiting for a wakeup signal".

i had just read that a tv/monitor must use less than 1w when 'off' to be energy star compliant.  it could use 100000w while running, but as long as it is less than 1w idle, it is energy star compliant.  the certification is kind of a misleading label if you ask me...the name itself implies that it should use less energy.

[ChrisOlson]

Your TV taking 28W in standby sounds to me like it's a digital TV/PVR type thing that is actually running much more than just the "waiting for a wakeup signal".

It's a really old rear projection Toshiba big screen TV that weighs about 500 lbs.  It was one of those deals where my wife came home one day and said she got a "good deal" on it at a garage sale.  Six dudes loaded it in the back of her truck for her.  I went outside to look at it and I asked her just how the hell I was supposed to get that thing in the house?  Good thing it's got wheels on it because I had to build a ramp from the back of her truck over the steps to get it inside.

The dang thing works good and it's got a good picture.  But it draws about 450 running watts and 28 watts when it's "off".  It's just a beast but we don't watch TV much and my wife likes the thing so we keep it around.  A power strip "fixed" the 28 watt idle power draw problem.

As for wasted power - it irritates me every time I go virtually anywhere and see the amount of WASTED power. Hell, even just driving down the road and seeing the odd street light on in the middle of the day... ONE of those things running all day is close to my daily power demand...!

I've always wondered if at Christmas time they have to fire up a couple extra generators at the power plant to run all the lights that people got.  And now they got inflatable decorations that have a motor and fan in them.  When I was a kid we just slapped up a wooden sleigh and reindeer thing for a decoration and it worked fine - didn't take a single watt to keep it erected in the yard.

The more "advanced" stuff gets, the stupider people become.
--
Chris

[ChrisOlson]

I understand, from forums such as this one, that Xantrex [formerly Trace] is now having its equipment either manufactured or whatever overseas [read: China??]

The Xantrex XW and GT inverters are built in Canada.  The smaller units like the ProSine being discussed here, from what I understand, are built in China.  When Schneider Electric bought Xantrex they wanted the technology and expertise for their renewable energy business, which Schneider is into in a big way now.  They did not care about the smaller portable inverters which are still marketed under the Xantrex brand.  If you go to the Xantrex website you will not even find the big XW and GT series inverters on there.  Instead there's a little ditty off to the right side there that says, "looking for renewable energy products?  visit Schneider Electric's website" with the link to Schneider's renewable energy business.

The XW-series is for residential and off-grid, the GT-series are for grid tie solar and wind.  The Xantrex GT inverters are available to up 500 kW, 1,400 amp, 208 volt three-phase, and the GT500 weighs 3,500 lbs.  That's a big frickin' inverter.  I don't know how many Outbacks you'd have to stack to match it, but I think it would a be a lot.
--
Chris

[defed]

my xantrex mppt says "designed in canada, made in china".