New Inverter

JESSICA

My EXELTECH 1100 just stop working. Hence, I am looking for a new inverter.
I would REALLY appreciate any and all recommendations and suggestions for a new unit.
The parameters are theese: Pure sinewave; 24 volts; rugged; 2,000 to 3,000 watts.
Please, I am NOT looking for "expert" opinions, rather, what I want is recommendations based on actual experience, of inverters that have actually worked fine for many years.

Thanks,

halfcrazy

Re: New Inverter

Magnums 4000 watt 24 volt sine wave is a real strong inverter with a great battery charger and is reasonably priced. xantrex made a sw+ that was 24 volt and they had a 2500 watt version that was good to just a little more pricey then magnum.
if you decide on a magnum do your self a favor and get a epanel from www.midnitesolar.com it will make the installation way easier and code compliant as well.

crewzer

Re: New Inverter

I use an OutBack FX2524T (2,500 VA, 24VDC, 120 VAC/60 Hz, true sinewave, sealed) that's located in my garage. I've been using it for two years to power a variety of loads [energy star fridge, HE washing machine, Hi-Def A/V system, computers, printers, modem, table saw, shop vacuum, etc. (though not all at the same time)]. The inverter and all loads have worked flawlessly.

I now work for OutBack, but I got the inverter long before I joined the company. :-)

Here's a link to product info and specs: http://www.outbackpower.com/products/sinewave_inverter/

Here are a few links to product-related reports I wrote:

http://www.outbackpower.com/forum/viewtopic.php?f=17&t=2134
http://forum.solar-electric.com/showthread.php?t=465

HTH,
Jim / crewzer

boB

Re: New Inverter

Jessica, have you called Exceltech to see if they might be able to fix your unit ?? Maybe it could work as a backup unit if fixable.

boB

niel

Re: New Inverter

i agree with boB that you should check into it getting fixed as exeltech is a good inverter too. maybe one of these guys can recommend somebody to look at it and maybe fix it for you. you also didn't say how long you had it or how it met its doom with what symptoms going on and i'd appreciate hearing more if you don't mind.

JESSICA

Re: New Inverter

Thanks for your recommendations.

My EXELTECH was just one year old. It was ok...if you only want to power small t.v. sets, computers, and the like. When I connected a small hair blower (only 850 watts --the Exeltech should produce 1100--), it literally exploded. Its internal fuses did not do its job, and so, almost half of the unit's IRF540N diodes burned. I guess some other parts are also harmed.

Yes, I did call the Company. When I told them that I had opened the unit to see damages they stopped answering. I wrotte them several emails: No answer.

Well, sometimes you loose.

Anyway, I need a bigger inverter...but not too big. A friend gave me a loaner, an AIMS 5000; but it is a modified wave and I fear it may harm my computers and other electronic equipment.

I cheked the MAGNUM and the OUTBACK. They look kind of heavy and bulky, compared to the dead one.

Thanks for your help.

crewzer

Re: New Inverter

Jessica,

Bad news about the Exeltech inverter and their customer support. The hair dryer probably drew considerable more than 850 W at start up (cold heater element = low resistance), but I would have expected the inverter to either handle the load or safely shutdown.

The Magnum and OutBack inverters are indeed pretty big. They include built-in battery chargers and other features that you may not want/need.

If you're looking for just a big TSW inverter, then you may wish to consider the Xantrex ProSine 1800.

See: http://www.xantrex.com/web/id/10/p/1/pt/7/product.asp
and: http://store.solar-electric.com/xapr18wahw12.html
and: http://www.xantrex.com/web/id/10/p/docs/pt/7/product.asp

Note that a big 120 VAC load on a powerful 12 V inverter requires connection to substantial 12 V battery bank via very heavy cables and an appropriately rated fuse and/or DC circuit breaker. Check the inverter's manual for recommendation/requirements for these items. For example, a full 1,800 W load could easily draw ~200 A from the 12 V battery bank. A 12 V battery bank rated at 800 Ah (9.6 kWh) or more may well be necessary.

I have a 24 V x 400 Ah battery bank (also 9.6 kWh) connected to my 2,500 W inverter, but I've never hit it with anything over ~1,000 W.

HTH,
Jim / crewzer

P.S. OK... I couldn't resist. :roll: I plugged my wife's hair dryer (1,875 W rating) into my 2,500 W inverter. Battery bank SOC was ~85% (-58 Ah on the Link 10). All started and ran fine. The dryer's low setting drew 746 W from the inverter (24.2 V x 38 A = 920 W in, or 81% inverter efficiency), and the high setting drew 1625 W (23.9 V x 74 A = 1,769 W in, or 92% inverter efficiency).

wxh3

Re: New Inverter

JESSICA wrote: »

When I connected a small hair blower (only 850 watts --the Exeltech should produce 1100--), it literally exploded. Its internal fuses did not do its job, and so, almost half of the unit's IRF540N diodes burned. I guess some other parts are also harmed.

Doesn't a hair dryer have a startup surge power so for an instant the power would have been greater than 850W?

wxh3

Re: New Inverter

wxh3 wrote: »

Doesn't a hair dryer have a startup surge power so for an instant the power would have been greater than 850W?

Reading the XP1100 manual it sounds like it is supposed to produce twice the rated power for 3 seconds. Then it is supposed to clip the voltage signal. Also there is an autoshutoff if current is exceeded. Basically, it sounds like you aren't supposed to be able to blow it by too much load.

Chuck46

Re: New Inverter

Its normal for inverters with good surge capacity to be bigger and bulkier and the Magnum and Outback are both very good inverters with good surge capabilities. I personally use two Outback VFX 3524 and like them. After a year they are problem free. From your description of the failure it sounds like the surge capacity is an important feature for you. Good luck

Chuck

crewzer

Re: New Inverter

P.S. OK... I couldn't resist. :roll: I plugged my wife's hair dryer (1,875 W rating) into my 2,500 W inverter. Battery bank SOC was ~85% (-58 Ah on the Link 10). All started and ran fine. The dryer's low setting drew 746 W from the inverter (24.2 V x 38 A = 920 W in, or 81% inverter efficiency), and the high setting drew 1625 W (23.9 V x 74 A = 1,769 W in, or 92% inverter efficiency).

HTH,
Jim / crewzer

boB

Re: New Inverter

I don't have hair.

That Exceltech shouldn't have blown up. I'm sure that was just a fluke incident. The Exceltech inverter is a high frequency design so it is lighter weight and smaller than the OB and Magnum.

boB

westbranch

Re: New Inverter

boB, other than the size/weight benefit to using high frequency is/are there any other benefits, and how about downside to using HF?

ERic

niel

Re: New Inverter

it sounds to be a defective inverter for sure as it was not supposed to react that way if we are understanding all of the circumstances correctly. being you opened the inverter they won't consider helping you due to the fact they think you caused it and if it was under warranty that opening of the inverter would instantly void it. lesson here is in the case of defective equipment don't open them up to see the damage or the blame falls to you.
for the record, i believe that was the 1st exeltech i've heard of being defective if my memory serves me right.

SolarJohn

Re: New Inverter

Jessica,

I've been using an Exeltech 1100 watt inverter for nearly 2 years and I've never had a problem with it. I've overloaded it on many occasions as I tested to see what it can and can't handle. I observed a reduced output voltage as I overloaded it, but normal output was restored as soon as I removed the load. Once in awhile I connect an 850-watt toaster, and it has no problem providing power to that. I would expect the same kind of surge with a toaster as you would have with a hair dryer, since both would start out with cold heating elements.

I would offer to fix it for you, but having no previous experience, I'm not sure if I would be able to. If you don't intend to have it repaired, would you be interested in selling it? If so, let me know how much you want for it.

boB

Re: New Inverter

Jessica, maybe you could call exceltech back and tell them to tell Gary, the owner and CEO (I believe) of Exceltech that we are having this discussion on the NAWS forum and would like to know their policy about opening up the unit after it failed within a year under your hair-dryer circumstances. I thought that Gary had even been on this forum at one time or another. He seems like an OK and reasonable guy.

Normally, these smaller--HF sinewave inverters don't have the surge that the big and heavy inverters have. Normally, that is... Not that they absolutely can not. That's all I can think of off hand, technically.

boB

JESSICA

Re: New Inverter

Thanks for your help and recommendations:

Crewzer:
I did consider the PROSINE 1800, but the 24 volts model is somewhat hard to find. (NAWS does not sell it, for example.) Also, the FX2425 and MAGNUM seem to be better deals for the money.

I did (and do) have the right fuse between battery bank and inverter: 110 amps, as recommended by EXELTECH. That fuse blew! But the inverter was damaged anyway. [Nevertheless, the internal fuses in the inverter are ok!]Cables are the right ones, too: 4 feet of 1/0, from batteries to inverter.

Thus, I just cannot explain how or why my EXELTECH failed.

WXH3:

As I see it, my 110 amp fuse should have protected the unit, but it did not.
Also, you said that "it sounds like you aren't supposed to be able to blow it by too much load", and that is exactly my point. No matter how hard I try to find somethin that was done wrong, I just dont find it. Either the 110 amp fuse, or the unit's internal fuses, or its protective capabilities, should have saved the unit.

Anyway, I think I will go for the MAGNUM or the OUTBACK.

halfcrazy

Re: New Inverter

you wont be sorry with either of those choices they are both good inverters

BB.

Re: New Inverter

Fuses are not intended to protect the device from damage... They are there to protect the wiring (internal/downstream) from catching fire/failing.

The internal over current/over voltage limiters are designed to protect against temporary overloads.

-Bill

JESSICA

Re: New Inverter

BB:

Yes, I knew that, but as a byproduct, fuses do protect the equipment, too, if they are the right size...

By the way, I would also like to know if my bias against modified wave are correct: Is it true that those modified wave inverters can damage electric equipment (like refrigerators, computers, t.v. sets, etc.)Please keep in mind that until I fix my unit or buy a new one I am using an used AIMS 5000 (MOFIFIED WAVE)

BB.

Re: New Inverter

Jessica,

Here is a nice Inverter FAQ from our host (NAWS).

Short answer is that a MSW (modified sine/square wave) inverter will probably run 80-90% of your typical home appliances OK... You may get some extra "buzz" or some hash/noise in your TV/Radio. And typical motors (electric drill, fan, etc.) will work OK too...

However, things like a Refrigerator motor are designed very closely to a matched load (pumping freon in your fridge)... And because a MSW inverter will cause a motor to use around 20% or more power than normal--they can overheat during long term use...

Also, since this is a non-sine wave--some electronics may fail very quickly (in seconds or less) because of this...

And, it is very difficuilt to know ahead of time which devices will work and which will fail...

In the end, if you need a portable inverter for occasional use--a MSW is pretty difficult to ignore the cheap prices...

If you are powering a home/long term cabin/using lots of "critical equipment" (computers, fridge, electronics) then I would bite the bullet and go with a true sine wave type.

And, the reason fusing does not normally protect electronic equipment from failures is that fuses have "thermal mass" that is greater than the electronics they are protecting...

So, a fuse/breaker on a motor works to protect the motor because the motor windings are heavy and take seconds or longer to overheat.

The diodes, FETs, etc. in a switching power supply have very small thermal mass/bonding wires, and the failures which can occur in milliseconds inside of a power supply that "pop" the fuse are frequently catastrophic failures... Flash-overs, substrate failures, etc.--so that when they fail shorted--the fuse is doing nothing more than protecting the wiring from over current.

Also, if some electronic part gets "stressed" (say static discharge)--these prime the devices for failures down the road--and no matter the size/type of fuse, the failure will eventually still happen.

When I was designing/spec'ing small and large computer/phone/network systems, I would oversize or design so that the fuse can be removed from the circuit...

The reason was that fuses are among the most unreliable components in a modern computer/power supply/system... The fuse is supposed not to blow at 80% or less load, but blow at 100-125% of load (seconds to minutes). Also, fuses work by "heating"--so they run hotter and thermal cycle versus the system they are in... So a fuse will age/fail more often than the electronics around it. And if you use a fuse with thermal delay, to allow for start/surge currents, then it would be way too slow to protect against a surge caused "pre-failure".

And, in large systems where you are penalized for downtime--whether it was a blown fuse, or a blown power supply FET--did not matter. So, drop the fuse and design the rest of the system to handle the surge current (if there is a failure) by popping the upstream branch circuit breaker...

-Bill

JESSICA

Thank you, BB.

Speaking about some motors, you say that "they can overheat during long term use..."

Now, since I will only use the modified wave inverter for one or two weeks, until I fix the Exeltech or buy the new one, do you think it can do any harm to my t.v. (Sony WEGA, 10 years old, 26 inches) or to my refrigerator (15 years old, 6 amp max, 19 cu. feet)? So far, I have not noticed any harm, damage or malfunction (I have been using the loaner for a week now.)

BB.

Re: New Inverter

Honestly, I don't know...

If your weather is cool, and you don't smell anything hot, and your fridge seems to be running normally--probably OK...

You can also run into "weird" issues... For example, many self defrosting refrigerators have a mechanical or electrical timer in them... On MSW inverters--clocks sometimes run erratically--frequently running twice as fast (the relatively flat crest of the MSW wave "looks like" DC which appears to the timing circuit as a "zero" crossing (blocking capacitor). Then the falling edge looks like another transition, etc... Ending up looking like 4 transitions per cycle--instead of 2. So, you could end up with twice as many defrost cycles (or incomplete defrost cycles, etc.)...

Don't know that this has happened to anyone--just an example of what could happen--causes an increase use in power because of excess defrost cycles/improper defrosting--and nobody would know unless they had a kill-a-watt meter on their fridge with a MSW inverter--which, with very old kill-a-watt meters was a problem in itself--as the early k-a-w meters overheated and failed when running on a MSW inverter--probably used a capacitor for voltage reduction to run the electronics--MSW pass more power through such a capacitive circuit.

If your TV sounds strange (snaps and pops), or the fridge motor smells/feels hot (in a hot room, just dump a load of warm food from the stove/store into the room)--then their time in your home may be limited...

And, just an FYI--you might wish to take a kill-a-watt and measure the power used by your fridge and TV (especially on standby/off--if you don't turn it off using a power strip).

New energy star appliances (especially the fridge) may save you quite a bit of power.

-Bill

n3qik

Re: New Inverter

JESSICA wrote: »

Thank you, BB.

Speaking about some motors, you say that "they can overheat during long term use..."

Now, since I will only use the modified wave inverter for one or two weeks, until I fix the Exeltech or buy the new one, do you think it can do any harm to my t.v. (Sony WEGA, 10 years old, 26 inches) or to my refrigerator (15 years old, 6 amp max, 19 cu. feet)? So far, I have not noticed any harm, damage or malfunction (I have been using the loaner for a week now.)

I have been running a 4 Cu. Foot refrigerator now for about 4 weeks on a MSW inverter. I would not worry about the refrigerator. Just take the time to get the new inverter that you feel is best for you.

I will post some current draws for mine, they are from a Kill-A-Watt meter.
Grid supplied= 125VAC @ 1.1 amps
Inverter supplied= 121VAC @ 1.8 amps

niel

Re: New Inverter

jessica,
we can't say specifically what will or will not happen using modified sinewave inverters for everycase, but the extra power that occurs in appliances from msw inverters is from the harmonic content of the waveform. this extra power is not what you really want ideally as it is dumped into your loads to be dissipated and the odd frequencies can upset some devices like clocks. items that have motors can fail altogether or just get their lifespan reduced from having to dissipate this extra heat that harmonic power caused. your short term usage of msw until a new or fixed sinewave inverter is obtained should be ok and is unavoidable. be cautious using some wall type adaptors we call wall worts as some devices have been known to fail instantly with the heaviest known failures reported here from battery chargers. most tvs will operate fine, but do have inverter frequency dependant circuits in some of them. if the tv is dependant upon the hz of the inverter and if off somewhat it probably won't hurt it even if it becomes unwatchable due to lines or flipping pictures.
as was pointed out most items will run ok on an msw inverter, but that doesn't mean there's no risk or that the life of some items won't be shortened, especially with long term use. use the msw inverter, but just be aware until you get your sinewave inverter again.

BB.

Re: New Inverter

n3qik wrote: »

I have been running a 4 Cu. Foot refrigerator now for about 4 weeks on a MSW inverter. I would not worry about the refrigerator. Just take the time to get the new inverter that you feel is best for you.

I will post some current draws for mine, they are from a Kill-A-Watt meter.
Grid supplied= 125VAC @ 1.1 amps
Inverter supplied= 121VAC @ 1.8 amps

1.8 amps / 1.1 amps = 1.63

Or 63% larger current... We don't know how much power (need watt measurements) but it does indicate you will have more I^2 * R heating losses (much of that ending up in the motor) and more losses from battery to fridge.

1.8^2 / 1.1^2 = 2.95 times more heating losses in motor winding because of higher current...

Is this enough to damage the fridge--don't know... Engineering rules of thumb--if something is 2x or less difference--then it can probably be ignored.

If it is 10x or greater difference, then one swamps the other...

In this case, 3x greater self heating losses is probably not insignificant. But--again, depending on how the motor was designed and built--can't really tell if there would be a problem because of this or not.

n3qik, if you have the watt usage (sine/square wave)--then one can see how much more POWER is used--and how much is being wasted (and dumped into the motor as heat) from the off-grid system of MSW vs TSW inverters.

-Bill

n3qik

Re: New Inverter

BB. wrote: »

n3qik, if you have the watt usage (sine/square wave)--then one can see how much more POWER is used--and how much is being wasted (and dumped into the motor as heat) from the off-grid system of MSW vs TSW inverters.

-Bill

The only watt meter I have is the Kill-A-Watt, so you will have to work with the numbers that are posted. But due to Hanna, I am stuck inside, so I have lots of free time today. I will place a temp probe and get so temp readings. Will post them up later. Heck this may get me to shell out the $$$ to get the Prosine 1800.

BB.

Re: New Inverter

The Kill-A-Watt has both Watt and PF (power factor) settings...

Volts*Amps*PF=Watts

That would tell you how much power you should be taking from your battery bank (of course, you have the DC side of the inverter to measure volts/amps--if you have the equipment/meters).

-Bill

n3qik

Re: New Inverter

Opps, forgot it had a PF reading. Back to square one.

Ok ran a more complete test between a MSW inverter and PSW grid supply.
The room was at 77 F.
4 CF Magic Chief refrigerator.
Results are rounded to the nearest tenth.
Temps are from a probe on top of compressor.
All other measurements are from the Kill-A-Watt.

Inverter
_____________Start____5M____10M____15M____20M____25M-End
Temp F.______105_____124____131_____136____140_____142 Peak
Amps________2.0_____1.9_____1.8_____1.8_____1.7_____0.0=OFF
P.F.__________.6_______.5______.5______.5_____.5______0.0=OFF
Watts________142_____123____115______113____109____0.0=OFF
AC Volts______121____120_____120_____120____120____120

Grid
_____________Start____5M____10M____15M____20M____25M-End
Temp F.______106_____125____130_____133____136_____136 Peak
Amps________1.4_____1.0_____1.0______.9______.9_____0.0=OFF
P.F.__________.8_______.7______.7______.7_____.7______0.0=OFF
Watts________134______97_____90______83_____83_____0.0=OFF
AC Volts______127____127_____127_____127____126____127

JESSICA

Re: New Inverter

Once again, thanks for all the good advice.

Now, I feel inclined to go for the Outback 2425, maybe just because I respect and admire Crewzer knowledge and expertisse.
Thus, I ask: How easy (or hard) would it be to install that inverter? Keep in mind that in order to istall the Exeltech I just connected the battery cables in the rear end and a power strip in the front end...and violá, that was it.

Regarding SolarJohn question:

SolarJohn wrote: »

Jessica,

I would offer to fix it for you, but having no previous experience, I'm not sure if I would be able to. If you don't intend to have it repaired, would you be interested in selling it? If so, let me know how much you want for it.

I don't know this Forum's rules or policies regarding selling and buying stuff in this pages. And I don't want to break those rules. So, before answering SolarJohn I would like to ask the moderators to, please, explain those rules, if any, relative to this point.

BB.

Re: New Inverter

I am new at the Moderation Game--but as I understand a simple new thread in the General Solar Topic with a For Sale announcement of personal solar related equipment is fine...

No ongoing sales/no commercial sales/no links to commercial sale websites. [corrected: please do not point to off-site sales of personal equipment--such as EBay).

And direct the people to contact you by email or through private messaging. I would suggest that you "close the thread" once the sale has been completed to avoid questions 4 years down the road.

NAWS/Niel will correct me if I am wrong.

-Bill

PS: I should add--if one or more first post users put items up for sale--I will be tempted to take them down as this is a solar discussion / support forum for NAWS and its readers and not an EBay type auction site.