Inverter Comparisons

hemmjo · October 2013

I was planning to use dedicated a MorningStar SureSine300-120 inverter to run a small (120 running watts) refrigerator for medical supplies for our mission in a remote area of the Dominican Republic. I was informed in another thread (thank you Mike) that even with the 600watt surge, that the SureSine 300 may not be able to start the fridge. Is anyone running a small fridge on one of these?

I had budgeted 250.00 for the SureSine. So, looking around for alternative solutions on this site, I find 600 to 1000 watt purewave inverters for 400+ to over 500+. Searching other places, I find inverters with similar specifications for under 300. For example Xantrex Prowatt SW1000 1000W True Sinewave Inverter for $270. There are also many others that come up when you search.

One down side to these larger inverters is they burn up almost as much no load current as the refrigerator does when it is running. The MorningStar only used a few milliamps at no load.

Our mission cannot afford to throw money away on un-reliable junk, but I can almost buy two Xantrex for the price of one Exeltech and have a spare?

You thoughts and experience are very much appreciated.

Thank You,

John

waynefromnscanada · October 2013

Re: Inverter Comparisons

There is a way around the large idle draw on larger inverters. Have the fridge thermostat turn the inverter on/off as needed. Will require a bit of rewiring on your part though. When the thermostat calls for cooling, it will start the inverter which will then run the compressor until the thermostat shuts down the inverter again.
And no, I would not expect the Morningstar to supply the huge surge required to get the compressor up and running. The start surge is far greater than most people realize.

BB. · October 2013

Re: Inverter Comparisons

Wayne is the "King" of using MorningStar 300 watt AC inverters beyond any reasonable expectations.

You really need a 1,200-1,500 watt minimum AC inverter (possibly 1kW if it has good surge capabilities) to run the fridge.

Using the Fridge thermostat to turn on/off the inverter can help reduce inverter Tare Losses--However, you have to get a large DC relay to control the Inverter's input power (a few inverters do have remote on/off inputs--Which could save you the relay issues).

There is no simple answer here... Refrigerators typically have 5x (or even more) starting surge. And many "second tier" inverters do not really meet their specifications (even some first tier devices don't always meet the specs either).

-Bill

jcheil · October 2013

Re: Inverter Comparisons

And, if it is a "frost-free" fridge, it may draw 500w-600w every 12-24 hours for an hour or so because of the heating element. That in itself will be twice as much as the 300w inverter can handle for an hour.

zoneblue · October 2013

Re: Inverter Comparisons

Or get an 24V Rv fridge. Either way you look at it, theres no way around spending a few bucks on off grid refrigeration.

icarus · October 2013

Re: Inverter Comparisons

How do we convince Morningstar to build a ~600-1kw Suresine? In 12 or 24 vdc config? Assuming you could surge it to start a good fridge, I would seriously consider getting rid of the LP fridge. A few more watts of PV, a couple more batteries and i could do it!

Tony

hemmjo · October 2013

Re: Inverter Comparisons

Thanks for all of your input. To clarify, this fridge is just a simple one, a bit larger than one you might put in a dorm room. It is not frost free. So the only load is the compressor, it does not even have a light in it.

Wayne suggested a good idea. To use the thermostat as a switch to turn the inverter on and off to eliminate the idle time current draw. To clarify when you mean --- I just disconnect the thermostat from the compressor circuit. Wire the compressor so it comes on whenever it is connected to a live circuit. Wire the Thermostat to the remote control port on the inverter. Then when fridge gets too warm, the thermostat closes, the inverter turns on which starts the compressor, when it is cold enough, the thermostat opens turning off the inverter.

This sounds like a great idea, no need for messing with heavy relays on the DC side.

My question now becomes, is it OK to start the inverter with a load already connected?

Thanks for your help,

John
http://villagemountainmission.org/

waynefromnscanada · October 2013

Re: Inverter Comparisons

hemmjo wrote: »

My question now becomes, is it OK to start the inverter with a load already connected? http://villagemountainmission.org/

Should not be any problems. I've had inverters wired directly to several water pumps over the years and used the pressure switch to control the inverters. No probs other than the motor being a wee bit slower to get going while the inverter stabilizes. That can be cured (yes, I've done it) by using a little wall wart (ac adapter) to power a relay. Result: Inverter starts to power up with no load other than the little wall wart, which is basically no load. By the time the DC voltage from the wall wart gets high enough to pull in the relay contact/s and connect the compressor, water pump or whatever, the inverter is up to speed so to speak and all is kosher.

waynefromnscanada · October 2013

Re: Inverter Comparisons

icarus wrote: »

How do we convince Morningstar to build a ~600-1kw Suresine? In 12 or 24 vdc config? Tony

Wouldn't that be AWESOME! There definitely IS a market for such an inverter, I have NO idea what's holding them back. Can't understand it at all.

vtmaps · October 2013

Re: Inverter Comparisons

waynefromnscanada wrote: »

Wouldn't that be AWESOME! There definitely IS a market for such an inverter, I have NO idea what's holding them back. Can't understand it at all.

Check out the Victron Phoenix inverters. They sell North American versions (120 volt AC, 60 Hz). The have a 24 volt DC, 800 watt inverter with a no-load consumption of 5 watts and a search mode consumption of 2 watts. I would buy one, but they are listed for marine use and have hard-wired outlets.

If you want a low power 24 volt inverter that can be hardwired into your system, look at the Exeltech inverters.

--vtMaps

techntrek · October 2013

Re: Inverter Comparisons

waynefromnscanada wrote: »

... using a little wall wart (ac adapter) to power a relay. Result: Inverter starts to power up with no load other than the little wall wart, which is basically no load. By the time the DC voltage from the wall wart gets high enough to pull in the relay contact/s and connect the compressor, water pump or whatever, the inverter is up to speed so to speak and all is kosher.

That's a good idea. I was about to suggest a delay timer but your solution is perfect.

mike95490 · October 2013

Re: Inverter Comparisons

vtmaps wrote: »

Check out the Victron Phoenix inverters. They sell North American versions (120 volt AC, 60 Hz). The have a 24 volt DC, 800 watt inverter with a no-load consumption of 5 watts and a search mode consumption of 2 watts. I would buy one, but they are listed for marine use and have hard-wired outlets.

If you want a low power 24 volt inverter that can be hardwired into your system, look at the Exeltech inverters.

--vtMaps

How does the starting surge capacity of Phoenix vs Exeltech compare ?

vtmaps · October 2013

Re: Inverter Comparisons

mike95490 wrote: »

How does the starting surge capacity of Phoenix vs Exeltech compare ?

The 600 watt exeltech claims surge to 1100 watts. The 800 watt victron claims peak power of 1600 watts.

I don't know how these specifications relate to real world startup surges. (I wish I did know, since I am interested in buying a smaller inverter that would be turned on 24/7). I want a listed inverter that can be hard-wired into a home system. That rules out the victron, but I like the specs on the victron better than the exeltech.

--vtMaps

hemmjo · October 2013

Re: Inverter Comparisons

I am now investigating the Xantrex inverters. Seems they make two versions that I would be interested in, PROwatt and PROsine.

The PROwatt is more in our price range, both spec sheets say "True sine wave" , Although in the spec sheet, the PROsine adds "(<3%THD)" to that spec.

For frequency that PROwatt says "60±.5Hz" while the PROsine says "60+/.05Hz(crystal controlled)"

Voltage is 104-127Vac for the PROwatt vs 120 Vac RMA -10%+4% for the PROsine

It is interesting the the PROwatt has more surge capacity that the PROsine, the 1000 models have continuous/surge ratings of 900/2000 vs 1000/1500

A guy going by the name 2manytoyz (cute name) has posted a nice test of the PROwatt2000 in the forums.
http://forum.solar-electric.com/showthread.php?16575-Xantrex-Prowatt-SW2000-testing/page2

Does anyone have either of these in use or and experience with either model?

On another note, I got an interesting reply from MorningStar in regard to my question sent to their tech support about the SureSine 300 and its ability to start my simple 120watt fridge.

They said, "The SureSine can handle up to a 600W surge for up to 25 minutes. It should be able to handle your refrigerator."

I might have to get one just to see for myself, if it does not work for the fridge, I can use it at home during power outages to run the TV etc. and stuff at night when I put the generator away to keep things quiet. Since is has, "Full electronic protection against AC overloads. Fully automatic reconnect after 10 seconds." It should not be damaged by an occasional overload.

John

Cariboocoot · October 2013

Re: Inverter Comparisons

hemmjo wrote: »

On another note, I got an interesting reply from MorningStar in regard to my question sent to their tech support about the SureSine 300 and its ability to start my simple 120watt fridge.

They said, "The SureSine can handle up to a 600W surge for up to 25 minutes. It should be able to handle your refrigerator."

From that we conclude that Morningstar knows nothing about refrigerators. I've tested several 'friges and not one of them would start with a mere 600 Watts available.

waynefromnscanada · October 2013

Re: Inverter Comparisons

Cariboocoot wrote: »

From that we conclude that Morningstar knows nothing about refrigerators. I've tested several 'friges and not one of them would start with a mere 600 Watts available.

As some of you know, I have a lot of experience with these inverters and fridges/freezers, and I have to totally agree with Cariboocoot on this one. Never have I come across a fridge or freezer, unmodified, straight from the factory, that didn't instantly cause these inverters to kick out on overload.
With extreme modifications to the fridge, (modifications the vast majority of people don't have either the tools, parts or understanding to make) some fridges and freezers can be made to start and run on the Morningstar inverter, but I have never heard of anyone other than myself being successful with the required modifications.
As they come from the factory, fridges and freezers demand a HUGE surge while starting.

hemmjo · October 2013

Re: Inverter Comparisons

I do believe Wayne that the 600 watt surge will not start the fridge. I just thought the response I got from MorningStar was interesting.

What I need to know now is the big difference between the Xantrax PROwatt and the PROsine inverters. From looking at the spec sheets for each it seems the difference is the PROsine has cleaner output. Looking at the tests that 2manytoyz did, the PROwatt looks pretty good also and it is a bunch cheaper.

Does anyone have experience with either of these models?

Thanks,

John

waynefromnscanada · October 2013

Re: Inverter Comparisons

John, I have had a Prosine 1800/12operating in standby mode for about 5 years now and find it to be a totally awesome unit. AWESOME surge. Starts heavy motors quicker than grid does here. Powers all large loads in my house and workshop without any problems, including a 12 inch, 12 amp cuttoff saw, mini-split heat pump/AC, water pump and all cooking appliances as well as washing machine. I would fully expect the 1000 watt Prosine to be every bit as good and reliable as the 1800 watt unit, just a bit less output. No experience with the Prowatt.
One item of interest - - I use GFI on the outputs of all my inverters, and have found that when there is a Ground Fault, the external GFI trips as expected, but also, the Prosine appears to also have a built in GFI circuit that requires a complete shutdown, including removal of the DC supply, to reset the inverter. Not a bad thing, but the first time it happens you might think the inverter just got blown.
I highly, highly recommend the Prosine because of my experience with it, but again, have no experience with Prowatt.

hemmjo · October 2013

Re: Inverter Comparisons

I hate when this happens....I was just about ready to order an Xantrex PROwatt, then I read some reviews on a popular online site (named after one of the worlds longest rivers) where I found them for sale. There are many good reviews and a couple really bad ones that mention Xantrex recently moving their manufacturing offshore, and the quality has plummeted in the last few years. Same situation with the PROsine reviews. More good, but still one or two negative.

I wonder Wayne, if your PROsine was made in the USA or was it made after they moved overseas?

Too add further to my confusion, while searching for Xantrex suppliers online I stumbled onto a KISAE SW1210. 1000wcont./2000wsurge True Sinewve, specs are very similar to the Xantrex.. $235.00 includes 3ft #2 battery cables. The price looks good to our budget, but I will not make this decision based on price alone. I have made that mistake too many times in the past.

Once again I value all input in making this decision which is going to be critical to expanding our mission. I would rather wait until I have enough budget to get what we need than to waste money and make a false start with something that fails too soon.

Thanks,

John
http://villagemountainmission.org/

waynefromnscanada · October 2013

Re: Inverter Comparisons

hemmjo wrote: »

I wonder Wayne, if your PROsine was made in the USA or was it made after they moved overseas? John

Hi John - - just out to the solar shed, leaning across the battery box and trying to read the upside down fine print with a flashlight, it seems to say "Designed in Canada, manufactured in China"
That is subject to another look in the daytime, but sure appears to say that at the moment.
The owners manual says on the outside back cover "Printed in China".

CDN_VT · October 2013

Re: Inverter Comparisons

hemmjo wrote: »

I was planning to use MorningStar SureSine300-120 inverter to run a small (120 running watts) refrigerator Is anyone running a small fridge on one of these?

Thank You,

John

some are , BUT with HUGE amount of wiring /relays & experiment of time. I have two , and in my eyes , overpriced ,under powered over pushed sine wave units. Build the unit so it can start a 500w surge .. Mine are collecting dust !!!
TBT (truth be told)

"They said, "The SureSine can handle up to a 600W surge for up to 25 minutes. It should be able to handle your refrigerator."

waynefromnscanada · October 2013

Re: Inverter Comparisons

CDN_VT wrote: »

(re the Suresine 300 inverter) I have two , and in my eyes , overpriced ,under powered over pushed sine wave units. Build the unit so it can start a 500w surge .. Mine are collecting dust !!!
Kill-a-watt your responses , please.

I guess it's all in what we expect of a 300 watt inverter. Obviously my expectations were not so high, so as I sit here with one of my two Suresime 300 inverters running everything in my house except the big draw items like microwave, water pump, band saw etc, I'm extremely happy and impressed with the two I have. I purchased the second one several months after the first one, because I was so impressed.
What is this one unit running and capable of running all at once? I'll see if I can remember it all:
Sat receiver; TV; computer; all inside lights, all 7 outside lights, all lights in the two outside buildings, chargers for FD pager and radio, cell phone and cordless drills, controls on the oil fired furnace, sound system amplifier - - - there's probably a couple of other things I've missed. It can and does sometimes run all these things at once, and has done so for years, and THAT is why I'm so very happy with it and why I bought the second one.
What the other one is running is a long story.
OH! And their design results in no need for fans, thus they run silent with no moving parts.

BB. · October 2013

Re: Inverter Comparisons

Inverters that don't have fans and sealed case inverters--I too like them a lot.

Drawing air through the inside of the inverters (and other electronics) brings in lots of dust, moisture, real bugs, and the fans themselves are mechanical and fail too. Fans are a common point of failure in any design you want to run 5-10 years 24 hours per day.

-Bill

Ski66 · October 2013

Re: Inverter Comparisons

Hello Everyone, I hope I can reply to this thread with a question ? If so, My issue is that I have installed a Klimaire mini split DC inverter / 19 seer, and currently run it from the grid, In testing the unit with a kill-a-watt , I see there is no surge what so ever, however it does power up from 50 watts increasing to about 1200 watts then runs on about 800 watts +/- The unit runs great.

My issue is when I transferred this to my solar power source, a SA 1500 (Samlex) pure sine wave inverter it works good but the power line going to the Mini split will get a little warm, and the fan on the Mini split will be a little noiser, its usually very quit. Some basic specs on the unit state; Power source : 115V - 60Hz , this is a 9000 BTU cooling unit & 10000 Btu heating. The SA inverter is set for 120 V - 60 Hz, just like the Grid, I am questing the quality of the Pure Sine wave, as it is set as the same as the power from the grid ? The inverter shows 120 V- 60Hz on a kill-a-watt, that is correct.

The line run to the Mini Split is about 12' or less. My question(s) are should I adjust the SA inverter for 115 V -60 hz even tho the mini split runs great on the grid power at 120V /60hz?

Or should I consider purchasing a SAMLEX PST 1500 ? Is there a difference in the quality of the Pure Sine wave ? and what would be the best Pure sine wave to use in this price range. I appreciate any information on this issue.

Thank you.

BB. · October 2013

Re: Inverter Comparisons

What you are describing does sound like less than a "clean" pure sine wave... Without an oscilloscope/spectrum analyzer--It is hard to say.

If the wiring is getting warm, you may need to re-evaluate the wire size. Not sure the Inverter is making that large of difference in wire heating (possible--just don't know).

Samtex seems to make reliable/lower cost AC inverters. And this is why the higher end inverters cost more and frequently weigh more too (more copper/iron inside).

Hopefully somebody else has more information to help you with your questions.

-Bill

waynefromnscanada · October 2013

Re: Inverter Comparisons

My Frigidaire mini split has basically the same specs as yours, but there is totally no difference running it on grid, or the Xantrex Pure Sine 1800/12.
Like BB said sounds like the waveform from your "sinewave" inverter leaves a bit to be desired. Likewise, if the supply wires are getting warm, they're too small for the load they're required to carry. The power draw of my mini-split can be controlled by adjusting the thermostat. just one degree off room temp will result in low power draw, while several degrees difference will push the unit to max power draw. Yours may or may not respond the same way.

CDN_VT · October 2013

Re: Inverter Comparisons

waynefromnscanada wrote: »

I guess it's all in what we expect of a 300 watt inverter. Obviously my expectations were not so high, so as I sit here with one of my two Suresime 300 inverters running everything in my house except the big draw items like microwave, water pump, band saw etc, I'm extremely happy and impressed with the two I have. I purchased the second one several months after the first one, because I was so impressed.
What is this one unit running and capable of running all at once? I'll see if I can remember it all:
Sat receiver; TV; computer; all inside lights, all 7 outside lights, all lights in the two outside buildings, chargers for FD pager and radio, cell phone and cordless drills, controls on the oil fired furnace, sound system amplifier - - - there's probably a couple of other things I've missed. It can and does sometimes run all these things at once, and has done so for years, and THAT is why I'm so very happy with it and why I bought the second one.
What the other one is running is a long story.
OH! And their design results in no need for fans, thus they run silent with no moving parts.

WOW that is quite a large amount for a single SS 300 Wayne .. Mine ,I did get it to open the overhead garage door motor.. Maybe I have got a second bad unit , first one lasted 150 pico seconds till it let the smoke out !!! (warranty replacement I received)Other than that , it won't start any 98- 120 watt draw freezers we have 3 . Two in service most of the year , one is just for the harvesting time till processed. Kicks out on seeing flour mill , 225 w , will run the cream separator... I can't go looking for different equipment just to make the SS300 happy. As BB pointed out , good design , but under powered in my eyes..

VT

waynefromnscanada · October 2013

Re: Inverter Comparisons

CDN_VT wrote: »

WOW that is quite a large amount for a single SS 300 Wayne .. Mine ,I did get it to open the overhead garage door motor.. Maybe I have got a second bad unit , first one lasted 150 pico seconds till it let the smoke out !!! (warranty replacement I received)Other than that , it won't start any 98- 120 watt draw freezers we have 3 . Two in service most of the year , one is just for the harvesting time till processed. Kicks out on seeing flour mill , 225 w , will run the cream separator... I can't go looking for different equipment just to make the SS300 happy. As BB pointed out , good design , but under powered in my eyes..

VT

Garage door openers are a huge load for any 300 watt inverter. I'm surprised you got it to work. And as to expecting a 300 watt inverter to start any fridge or freezer that hasn't had MAJOR modifications to help it get started, to be honest is a definite no go for ANY 300 watt inverter. Fridges and freezers are notoriously hard to start, that's why manufactures recommend no extension cords, and a dedicated circuit breaker for each when operating on grid. Most folks just don't realize these items have HUGE start surge demands and will almost instantly kick the inverter out on overload. Almost ALL motor driven devices except for small household fans and small hand drills, have very large start surge requirements and are not suitable loads for any 300 watt inverter. You will notice that there are no motor driven loads in my list of all the things my SS-300 runs. And it's just the electronic controls on my furnace that the SS300 runs. The Xantrex 1800 runs the burner.
My other SureSine 300 does run my fridge and freezer, but ONLY because both fridge and freezer have had MAJOR, MAJOR modifications to the starting circuits as well as added capacitor start. A VERY complicated and difficult process. Far better to use a much more powerful inverter to run those items. You'd probably need a 1000 watt inverter, and maybe even larger, depending on the inverter design to get them started.

CDN_VT · October 2013

Re: Inverter Comparisons

Yes I have read those MAJOR mods you did, I also played with the caps & starting circuits etc.
I decided to move to a larger inverter for ease of use. Im frugal ,for the amount of mods you did , I couldn't see me justify my time and hoping my wife would understand .
Just the external gen set was trying..

Garage door openers are a huge load for any 300 watt inverter

Well it can open it and close it with no red light flicker , that is the largest or only motor I have seen it run. It has been passed on on three garage sales .

Ski66 · October 2013

Re: Inverter Comparisons

Hi Wayne,
Thank you for the information. The Samlex inverter is specifically used for the Mini Split , there is no other loads
on this when it runs off it. I am well within the watt range , as it never exceeds the 1500 watts ( The mini split uses about 1200 watts at max load ) I have 12-2 hardwire from the inverter to the mini split, the wire does not really get warm or hot, but the connecting plug that goes to the outlet will get warm ? it is rated for 15 amps / The Mini split is rated for a minimum of 15 amps , and a max of 25 amp breaker, my disconnect is fused with a 20 amp fuses , they have never tripped or blown. I'm not worried about the inverter as it has the GFI , but I want to make sure this inverter will not damage the Mini Split. The fan noise is from the outside unit only. Currently I only run this off the grid until I double check all the specs on the inverter (Clean sine wave) , wire, and connector / plug. I am going to start with checking out the specs on the plug, if they make a 20 or 25 amp heavy duty one for starters , I believe Samlex makes a nice pure sine wave inverter as it runs my computer , electronics , even the digital washer with no issues, but all those items use low watts , around 300 watts max.
I have been in touch with someone that stated the connecting plug could get warm because at the point of contact from the 12-2 wire to the male plug is less then a
12-2 wire connection, but it is a very small run from the male plug to the outlet, This seems to be what I am looking into, as the wire does not get warm or hot, but the plug does get warm when connected to the samlex inverter. I do keep the mini split set at 70 degrees, and it produces and keeps the house warm, Yes, I do have a digital bar that gives me an idea of how many watts are being used, as you mentioned it does vary even on a degree up or down. I use to use oil / radiator heat , and I have got admit these
Mini Splits are great. Thanks again for the information , should you think there is any thing else I could check, please advise.
Thanks, Paul

CDN_VT · October 2013

Re: Inverter Comparisons

If you have two plug holes on that SA 1500 (Samlex) you could , wire in two plugs and parallel them so both plugs are used having a better contact area between the plug & the SA 1500 (Samlex) GFI. Warm of any sort is not good.. at connections . Since you only use the SA1500 for one item , on a picture look up , I see two spots for two plugs.
I would also buy those industrial type of heavy duty plugs .
Attachment not found.

See if that helps
VT

Inverter Comparisons

Comments

Categories