Just ordered a new residential fridge and was wondering what size/type pure sine wave inverter is best/needed.
Larry
Larry,
What is the "start up" amps? Use that plus 25% as a reasonable objective.
Versus replace the main inverter?
The idea that a small inverter saves energy is difficult to quantify.
The possible differences in efficiency for a specific load are tiny.
Almost all major inverters run 90% efficiency.
So a 750 watt load loses 75 watts.
A 92% effeciency unit loses 60 watts.
The separate battery cabling necessary to hook up a inverter consumes electricity itself.
No free lunch.
The idle voltage differences are measurable but very small.
I know that power consumption per foot of wiring are published.
Wiring in a small inverter using even giant multi strand wiring would not seem to be much of a power savings.
I do not know of any oem rv that runs multiple inverters.
Even 110 volt wiring consumes some power.
Unless you have a non inverter small rv and just trying to get some power to something?
If someone is going to post about idle current and efficiency levels please compare the exact purported power saving and then factor in exactly how much power the 12 volt cabling consumes to hook it up?
Unless you are not intending to replace the main inverter with a full sine wave unit?
A 95 freedom can not be fit with a BTMS. Never will charge the batteries correctly.
Both mk and lifeline state that their batteries require a BTMS charger
Larry, our full sized Samsung uses about 170 watts while running. Maximum draw is 6 amps or 720 watts. This is pretty rare, a warm start. So if you are looking for a smaller inverter look for one in the 600-1000 watt continuous range. I am using a Victron 800VA Phoenix inverter. It produces 650 watts continuous, 1500 watt peak. The Victron 1200VA produces 1000 watts continuous, 2200 watts peak.
https://www.victronenergy.com/upload/documents/Datasheet-Phoenix-Inverter-VE.Direct-250VA-1200VA-EN.pdf
Victron Phoenix 12 Volt / 800 VA Pure Sine Inverter (https://baymarinesupply.com/chargers-inverters/victron/victron-phoenix-inverter-800va.html)
You should have the appropriate sized 12v wire for the load and distance, a 12v fuse of the appropriate size at the battery end and a switch. At the output end of the inverter you should have a circuit breaker box and a circuit breaker before the refrigerator outlet. Most smaller inverters have a GFCI outlet but this will not protect the circuit in the event of a overload.
Efficiency is just one part of the power cost of using an inverter. You have to look at how much power it takes just to have a big inverter on. The Victron 800VA uses 6.5 watts to be on. A common Magnum MS2812 uses 30 watts just to be on. The Victron 3000VA Multiplus uses only 20 watts to be on.
Lots of choices out there.
This 1200w inverter has been working great with our Samsung for almost 3yrs. Plenty of power for the fridge, with extra to spare for other small loads (Tv, etc), and allows us to shut down the main inverter when not needed. It has instant automatic switching to shore power and the optional remote panel provides on\off control from inside the coach.
Amazon.com: AIMS Power PWRIX120012S 1200 Watt Pure Sine Inverter, Built In... (https://www.amazon.com/PWRIX120012S-Inverter-Transfer-Switch-Constant/dp/B00TI1D5JK/ref=sr_1_8?keywords=aim+inverter&qid=1558480985&s=gateway&sr=8-8)
I assumed that since the Magnum I have is a modified sine wave, I needed a pure sine wave inverter to properly run this new fridge. Am I incorrect in my assumption?
Brett, I will see if the specs show what the start up amperage is. I don't recall seeing them when I was looking.
I guess that I am more worried about damaging the unit more than a minor savings in energy at this point. That might come back to haunt me, don't know for sure.
Thanks,
Larry
bdale, thanks, I will look at the link. You and I were typing at the same time.
You should not need a pure sine wave inverter as the Samsung turns the ac into dc so they can handle anywhere in the worlds power. I don't know about other brands but I researched it a number of years ago now when I had FT put in my fridge. That was what the said as well.
I also remember reading that about the Samsung. I thought it sounded rather inefficient. You change battery DC power to AC with the inverter, send it to the fridge, which then changes the AC power to DC. Anyway, I put it to the test, and ran our Samsung 24/7 on the OEM modified sine inverter for about a year. It ran just fine that way. Then we upgraded to a larger capacity pure sine inverter.
But this Samsung trivia is not relevant to the OP cuz he said (in another thread): "I just ordered the Haier 9.8 top freezer refrigerator from Lowe's".
Larry needs to determine if the HAIER fridge will tolerate a modified sine AC power supply.
My Haier did not tolerate the prisoner 2500 well. It would go into a fault mode with alarms at random times. Since going to the Victon pure sine wave no more problems.
Always thought I had an intermittent problem with the refrigerator but now realize it was power related.
My Haier is 6 plus years old
Larry this is what I installed along with fuse, circuit breaker and battery switch. Works great!
https://www.homedepot.com/p/GoWISE-USA-1-000-Watt-Continuous-2-000-Watt-Peak-Pure-Sine-Wave-Inverter-PS1002/306070582
Techno-babble ahead.
Most Samsung refrigerators now use Digital Inverter Technology also called Variable Frequency Drive (or VFD in short). Samsung uses a variable frequency motor that can change its speed if the frequency of the incoming alternating current is changed. Thus to achieve this variable-frequency a rectifier is used to convert the incoming alternating current (AC) to direct current (DC) and then uses pulse-width modulation in an electrical inverter to produce AC of a desired frequency. This results in significantly better efficiency and electricity savings. The refrigerator compressor speeds up or slows down as cooling loads change. (Compiled from several articles)
Almost anything that uses a rectifier to change from AC to DC (mobile device chargers, laptop chargers, things like this) will work OK with many modified sine wave (multi-stepped) inverters for incoming 120v AC power. But there a lot of devices that work better and will last longer with a pure sine wave inverter. Nothing works worse with a pure sine wave inverter so for a bit more money you get a universal power source and no concerns.
For all of your mobile device charging find chargers or outlets that work on 12v to begin with. Double check what your devices need. There are Quick Charge devices that provide hight voltages and current for devices that can use them.
Amazon.com: Blue Sea Systems Dual USB Charger Socket: Gateway (https://amazon.com/Blue-Sea-Systems-Charger-Socket/dp/B0082CXEI8/ref=sr_1_12_sspa?crid=16WA30ZGYDX12&keywords=12v%2Busb%2Boutlet%2Bmarine&qid=1558536478&s=gateway&sprefix=12v%2Busb%2Boutlet%2Caps%2C221&sr=8-12-spons&th=1)
Amazon.com: Quick Charge 3.0 Car Charger, CHGeek 12V/24V 36W Aluminum... (https://amazon.com/Charger-CHGeek-Waterproof-Voltmeter-Motorcycle/dp/B07GKJ4ZLC/ref=sr_1_1_sspa?crid=16WA30ZGYDX12&keywords=12v+usb+outlet+marine&qid=1558536331&s=gateway&sprefix=12v+usb+outlet%2Caps%2C221&sr=8-1-spons&psc=1&smid=ARJSICEVESDQN)
Amazon.com: AUKEY Car Charger with Quick Charge 3.0, 39W Dual Ports for... (https://www.amazon.com/AUKEY-Charger-Samsung-Qualcomm-Certified/dp/B01B2BMIMS/ref=sr_1_12_sspa?crid=1XK4WC0735JWI&keywords=qc+3.0+car+charger&qid=1558536840&s=gateway&sprefix=QC%2Caps%2C232&sr=8-12-spons&psc=1)
Better yet, why does the coach have a Magnum MODIFIED sine wave? I am aware Magnum has a series of modified-sine wave inverters, but why would one choose them over sine wave. It can't be just to same one-time costs.
1.
Might be to save money. Some folks are all about the bottom line.
2. Emergency replacement scenario and nothing else available?
3. Failure to do adequate research prior to purchase?
Thanks everyone for the comments. I will try to locate one of the pure wave inverters local so that I don't have to wait on shipping this holiday weekend. I see from Alan's link that a 1500 watt inverter is only $20 more. Any advantages/disadvantages for the extra power potential?
Larry
OK, just ordered the GoWise 1500 watt pure sine wave inverter. Prime shipping by Friday.
Larry
A Magnum is capable of being a fully integrated system. Gen start, solar, battery temp system, battery management system....
Good job Larry, And ya you could have purchased a full blown Magnum set up at 10-15 times the $190 price of the dedicated pure sine wave inverter. For what CaFlashBob lists you are going to spend close to $3000. There are lots of options out there for each of us to choose for ourselves based on our own perception of needs.
Not used to the idea that a lot of current Foretravel owners cannot and/or will not outfit their coaches with up to date equipment.
Cannot I totally understand. Or those who travel pole to pole or run their gens always. Or have large enough solar systems.
Never built anything just to get by.
Some talk price. I talk quality. And longer life.
$3k? A set of oem batteries cost almost that much.
I have found a top quality electrical system that is demonstrable to a prospective buyer got every dime back I invested as a sales manager for Foretravel.
If the purpose of this Forum is to find alternative equipment that is a good as every coach here was outfitted with new but for less money, god bless. Happy to help.
"Good things aren't cheap and cheap things aren't good." Old horse trader made me memorize that.
False economy in my experience. Especially if the coach is a "keeper."
You will replace things twice versus oem stuff. Plus the usability is less.
As a Foretravel guy I guess I have lasted too long. I can not and did not ever give a single customer who bought used coaches from me less than what Foretravel sold new.
IF I had cut corners the owners would have figured it out and that would cost me and my store a lot of repeat sales and profit margins and my phone would have rang more with unhappy owners.
I assume anyone looking at used coaches that is an a experienced owner would discount the price they might pay if substandard equipment is present. Barry's web site shows what was in these new.
I sure did. In many ways a wholesale priced unit worked perfectly for me.
That way I could afford to upgrade the entire coach to current new coach standards. 10 cents on the dollar versus new.
The idea that I need to be 6-8 cents on the dollar versus new is new to me.
Did not realize that that many posters here do not have the wherewithal to keep up their coaches to at least the original condition.
Sorry times are that hard.
God bless. MY idea is to have the same experience as the first owner had. Or better. And every used customer I sold got that same quality.
I guess I am wrong. Get by is the key? Seems like I wasted a lot of my time posting things that are beyond the ability or interest of most or some here.
Oh well. Times change. I know what I expect a coach to be capable of. My curse.
If you don't know that's one thing. If you are financially strapped that's another thing.
Like i said. Show me how to get equal quality for less money and I am all ears.
You pay less you get less is my 35 year experience in the rv biz.
I assume the small inverters are not UL listed? If it causes a fire your insurance may not pay. Your insurance can sue you for the loss. DOH requires UL appliances. RVIA requires UL. Or equal.
The idea of installing a non tested high capacity electrical device in my coaches basement is a no go.
Been in the burn ward long ago.
Tell me that some kind of test sticker is on these?
You can get a Magnum MS2812 with the interface for about $1700 if you shop around,yes you can buy more devices but this will
work good,was reading the Magnum manual and if your generator is not set up for auto start the auto start module may not work.
Barry,it does not matter or serve a purpose why his coach had a modified sine wave,it has one and he wants a better one just
help the guy.
I regret buying a cheaper Chinese inverter. It's still working today, but it does not perform as advertised.
Victron IS a fully integrated system. Gen start, solar, battery temp system, battery management system. All capabilities are there when choosing the right components.
I'm running integrated Victron invertor, temp sensor, solar controller, and color control panel.
I can set charging profile to anything I want, down to tenths of volts desired. When at the coach I can check on status via display panel or the Bluetooth app. When away from the coach I can check on status via internet connectivity to the Victron using their app.
Victron is fully integrated. As are some other systems. Having choices of FULLY INTEGRATED SYSTEMS is good for consumers.
It's fascinating to read the Magnum vs Victron battles between Roger & calflashbob. Based upon my experience and the experience of others here both are excellent systems and worthy of consideration. We have a Magnim 2812 and it performs flawlessly, while others have a Victron snd are similarly pleased.
I believe a few of us have the Xantrex SW-3012 and are just as happy with it also.
The magnum auto start has a 25 second gen preheat setting if needed plus a gen start sensor and will retry the gen 4 times.
The victron web site blog mentioned buying a free standing magnum auto start when questioned closely
If your gen has a built in preheat profile then the victron can trigger it once as far as I can see.
Plus the autostart can be integrated with the air conditioning and heating plants fairly easily if you have Dometics and aqua hot or heat in the a/c's with a wall controller.
If I ran a small non UL inverter it would be with auto fire suppression and know I am taking a fairly big chance
I too had two prior rvs I put Xantrex SW-3012 in with great results. Because of the way these rvs were wired (similar to my FT) I was only able to use one of the two. 110v legs. And so on my third install I selected the Xantrex SW-2012 using the one leg that was offered. The difference for me then was 150 vs 100 amps that each offered for charging. 100 amps was plenty. Given the choice again I'd select the Xantrex SW-3012 for $200 more. Given the need for a lower charge rates (posible with lifepo4. batteries) you can down rate the charger on either unit. Never had an issue with Xantrex. For a stand alone new inverter (with no charger) for my Samsung refrig I selected the Xanrex inverter 2000 over 1500 upon recommendation of the retailer Don Rowe based their experiece of reliability. I bought from Don Rowe because they had the best price and they always have given me good support over the phone.
Xantrex Freedom X 2000 Pure Sine Inverter
Description
Freedom X 2000 True Sine Wave Power Inverter - 12VDC - 120VAC - 2000WTrue sine wave 120 Vac inverter with built-in transfer switch. Designed for recreational and commercial applications.The Freedom X inverter offers premium performance in a lightweight compact package. It cranks out full output from -4F - 104F for operation in all climate temperatures. The extended surge rating of the Freedom X makes it ideal to start difficult loads including fridge and microwave. The quick connect terminals at AC IN/OUT make installation a breeze.Features:Extended Surge Rating:nbsp;Surges to 2X continuous power for 2 seconds for motor loadsTrue Sine Wave AC Power:nbsp;For operation of sensitive and motor loadsIgnition Control:nbsp;Feature to turn inverter on/off via a 12 VDC signal and to minimize battery drain by switching the inverter off when the ignition key is turned offWide 10-18 VDC Input Range:nbsp;Ensures inverter operation on high voltage alternators found on many new vehicle chassisBuilt-in 30A AC Transfer Relay:nbsp;Senses when outside AC Power is present and transfers the load from the inverter to the source of incoming power (shore or generator). The unit also automatically switches from invert mode to charge modeQuick Installation: Huge wiring bay for easy access and quick connect AC in/out terminals for fast easy wiring
The one I had that was original to the rv lasted for about 1.5 years after I bought the coach.. 15 yrs of service... and it was good also.... until it wasnt... Then I moved on... I think everyone should read up on what makes you happy and what fits your needs.. They all basically the same thing for a little extra money.. really goes to a ford vs Chevy thing (almost ) at the end of the day.. I think overall you cant lose but the Devi is in the details..Read... Amps used while on idle is a big deal unless you have a large bank.. if so I wouldnt worry about it... I am very happy with all my victron parts but they could be anything else and I would probably be happy with it also.... unless it was my old inverter which died .. ^.^d
I see some pluses for Victron in that they have a function and part for about every application/Function you want.. accessorize with Charge controllers or Color monitors or Gen start or?
Read up on both and see what works.... you probably wont get into the details if your not interested in that stuff... but I do know that you can get automatic updates on the victron just by a wifi connection and turning on auto updates.. think that is a plus
So all this talk with an inverter if Sanyo products that use a converter, why not just bypass the converter and not be concerned about a pure sine wave inverter? Has anybody gone that route and just eliminate the need for a inverter circuit, Or AC power at all? With just the DC circuit you would not lose amperage, as you do with an inverter. Then if you needed DC to DC Converter, I'm sure it would be less money, and a whole lot less hassle? There is DC power behind the fridge already. But the amperage draw may require a larger wire that's all? Does the specs say what DC voltage is needed? What am I missing here?
Constant DC voltage of whatever the manufacturer requires. Not variable voltage from low 12's to mid 14's
Tom, the Samsung (I don't know about Sanyo) uses a rectifier is to convert the incoming alternating current (AC) to direct current (DC at some voltage, likely not 12v) and then uses pulse-width modulation in an electrical inverter to produce AC of a desired frequency.
It is the AC voltage at a variable frequency that gets you the variable speed compressors that are much more efficient than an on/off compressor.
These refrigerators are very efficient. Ours uses less than 70 watts per hour, about 135 watts max. The maximum 120v load is 6 amps or 720 watts. That defines the max power you would need from a second small inverter. A little extra wouldn't hurt if your going to run more stuff.
Going a little futher, the ac input goes to a full wave rectifier which is smoothed into approximately 170 volts DC. Then it is reconverted to AC with the capability of changing the frequency of the AC based on the load of the three phase compressor of the cooling unit. There's the efficiency, no start capacitors required for three phase and the compressor only runs at the level actually needed rather than running full bore with high amperage spikes on start every time like a conventional refrigerator. It's comparable to using a throttle to control a car rather than an on-off switch.
If you're feeling real adventurous, utilizing today's high voltage solar panels it's likely the DC output could be fed directly into the inverter system, bypassing the need for AC entirely. Probably a good application for a super capacitor bank to store energy rather than a battery bank.
I use a very similar device , a variable frequency drive, to convert single phase ac input into three phase AC at a controllable frequency to drive a 4KW spindle on a CNC flat table router. These are elegant, efficient devices.
Is this technology also applicable to air conditioning compressors? Sounds like it would be nice to have in our rooftop A/C units.
Absolutely. The ductless mini split units work the same way, that's how I now have a SEER rating of 22 on a 1.5 ton air conditioner for my house. Cut my AC bill by 2/3, a significant thing in South Tx. I've thought long and hard about retrofitting one of these units into the coach. Imagine some one will come up with a rooftop unit eventually and own the RV air conditioning market.
Dometic et al is no doubt aware of the possibility but I guess they're happy selling 25 year old tech and are waiting for the Chinese to build a RV unit.
+2 on what Chuck p. said it's been possible for at least 20 years, Samsung has a 6 phase ac compressor. Oil in the refrigerant to lubricate compressor bearings reduces heat transfer coils efficiency by 15-20% this was solved 15 years ago with electromagnetic bearings floating the compressor shaft , just super complicated and $$$$$$ Canadian company builds it and it runs at 85,000 rpm and you can stand a nickle on it without it falling over from vibration Never seen one installed, but a KC supplier sent me a picture this week of 2 York 400 ton units with this technology waiting to be picked up and installed. ARI SEER numbers are somewhat bogus with lots of factors applied, EER numbers don't lie. Our rooftop units are simple but inefficient robust 70's tech strangled by the unit mounting arrangements and physical size. Double down on the condenser coil size and switch to more efficient fan motors and they could get down to somewhere in the 800-900 watt range vs 1500 watts plus each. Running down the road running one roof ac unit with the Genny off is doable at a moderate investment $1500 each or less. Compressor amps are pretty much fixed until you increase the condenser coil size, fan motor power can then be modulated based on demand. Solar powered why not. With some work I can get 4 full size panels on my 36 footers roof.
Our Samsung wotks perfectly and appears to be very efficient. However it does have some interesting operating characteristics. Ours starts out making some moans and groans and then seems to run for a very long time. These appear to just be the normal characteristics of its high-efficiency mode of operation and I'm very happy to live with them!
So why turn DC into AC to just be turned back into DC and back into AC again? LOL. Somebody should hack the samsung to run off DC.
I think it is converted to DC at some other voltage the 12 v and the uses a Pulse Width Modulation to get back to some AC voltage ( maybe not 120v) at a variable frequency to vary the compressor speed. Any hack might fry the refrig. As it is it is very efficient.
Variable
Load, and it gets more complicated, Samsung has a six phase compressor. They can be so highly integrated that repairs are not possible after leaving factory