Ideas for back up inverters?

softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
This is as much a prepping question as a solar question. Though many off gridders are inclined to prepping.

Looks like my Outback FM80 should last a very long time. The 3648 inverter now has 5 1/2 years of use. I "expect" 8-10 years of use and feel that it may last 20 years due to being cool and rarely under heavy load. 

Hard for me to buy first class equipment for unforeseen long term emergencies that likely will never materialize. Just can't afford that. So - off to the "sub $500" class of inverters. That usually relegates us to unknown Chinese names complete with 90 day warranties. As compared to 5 year warranties from reputable names. 

Having worked hard on reducing my loads from defrosters to chest freezers and chest freezer/fridge conversions - I hope a 300 watt inverter could bear the burden. I can use a genset for running the well pump. The microwave is an interesting quandary - I do have some large modified sine wave 12V inverters from my days of building the shop. 

This Victron is intriguing with its low price, pure sine wave, Victron name and 5 year warranty. https://www.amazon.com/Victron-Energy-Phoenix-Inverter-VE-Direct/dp/B076TCJKN6/ref=sr_1_3?dchild=1&keywords=Xijia%2B3000W%2B(Peak%2BPower%2B6000W)%2BPure%2BSine%2BWave%2BInverter%2BDC%2B48V&qid=1598537879&sr=8-3&th=1

Currently running two chest freezers and a freezer to fridge conversion that only cycles during  the daytime. Yet it is certain that all three will be on at the same time from time to time. Unit does say 700 peak watts and it is a Victron. No need to de-rate I think. 

Why buy a no name inverter with a 90 day warranty when we can get a Victron with a 5 year warranty?
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries

Comments

  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    edited August 2020 #2
    Not top notch build quality according a review - yet still has a 5 year warranty.

    One review has this to say - "Does use 48 volts and very quiet, output is not ground referenced. Will burn out if connected to household wiring." Unsure how to take that.

    I've seen plenty of our posters get years of service out of very small inverters.  Plus - what is the point of downsizing to small loads while using a large inverter that uses ample energy?
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    I think they are saying the average home uses >>300 Watts of energy... Obviously, you would be powering the minimum loads with a 300 Watt inverter (LED lighting/security lighting, USB loads, small radio, etc.).

    Not "ground referenced" AC output--Just means you should be able to connect to a (typically) ground bonded AC Neutral main panel (and battery bank negative bus is also tied to the same "AC safety ground") without issue. MSW inverter, generally, will see a ground bonded neutral and dc battery bank as a "short circuit" and trip fuses and/or blow the inverter's switching transistors.

    And "prepping" -- You are going to be spending money you don't want too... For decades, had an old genset I inherited. 3,000 Watt B&S--Noisy as heck. Never really needed it except for remote operation when no utility power was available.

    Now have 4 gensets. First one now ~50 years old, not sure even will start. Second cheap one got for Y2K--I was not worried, wife was. A 3rd nice Honda eu2000i because don't trust California utility power any more 15 years or so ago. And a new Honda eu genset because of California blackouts last year and this and first times I ever need a genset in 65 years at my home(s) in California. Even turned my 93 year old father-in-law immigrant into a bit of a "prepper" (really my wife did, by talking about what we did with gensets and food storage).

    The other old saying... One (operating power source) is 'none'. Two (one spare) is one. Three (one running, two spares) is 'one spare'. Coast guard would install 3 redundant power systems at a lighthouse (in decades past, not sure now). And would "rotate" the operation of 3 engine systems to ensure all where functional.

    What ever you chose, "one" backup is not really enough. Choose two different brands/models--Then hopefully a common fault won't take the prime/backup 1/backup 2 all at the same time.

    Really depends on what you need the power for... Assuming LED lighting and a portable radio is the "minimum"--Even a 12 volt solar battery system works great--And a couple (3?) USB chargers for cell/USB power packs/etc.

    For short term 120 VAC power--A genset or two (with preserved gasoline, or possibly a propane genset) will allow emergency repairs while "other power" (solar, utility, etc.) power is not available.

    Obviously fuel (gasoline, diesel) eventually goes bad. And eventually you run out (no further fuel available if SHTF).

    Batteries have limited life (especially the small USB/Li Ion packs)... Back to looking for grandfather's (or now great grandfather's) hand cranked drill, hand saw, etc. to do repairs.

    The big loads always ended up being the fridge and freezer... Me, I was tending towards dried foods/shelf stable foods for longer term emergency supplies (if the panels/batteries/inverters don't fail, there is always the chance the compressors will).

    Now--To play with my wife--Talked about Pemmican as a stored food (nothing hi-tech there):

    https://en.wikipedia.org/wiki/Pemmican

    I don't see living in a "city/suburban" home for more than a few months (no water, no gas, no power, no sewage) before it become untenable (either my own living conditions, or those around me--Most who probably could not go 2 weeks without help).

    COVID has certainly changed much of life--No need for offices(?). Can telecommute for many jobs (certainly not all). Being on properly with well water/septic/etc. makes prepping "easier" and part of the daily lifestyle anyway (further from stores, fewer "utilities").

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    BB. said:
    I think they are saying the average home uses >>300 Watts of energy... Obviously, you would be powering the minimum loads with a 300 Watt inverter (LED lighting/security lighting, USB loads, small radio, etc.).

    Not "ground referenced" AC output--Just means you should be able to connect to a (typically) ground bonded AC Neutral main panel (and battery bank negative bus is also tied to the same "AC safety ground") without issue. MSW inverter, generally, will see a ground bonded neutral and dc battery bank as a "short circuit" and trip fuses and/or blow the inverter's switching transistors.

    And "prepping" -- You are going to be spending money you don't want too... For decades, had an old genset I inherited. 3,000 Watt B&S--Noisy as heck. Never really needed it except for remote operation when no utility power was available.

    Now have 4 gensets. First one now ~50 years old, not sure even will start. Second cheap one got for Y2K--I was not worried, wife was. A 3rd nice Honda eu2000i because don't trust California utility power any more 15 years or so ago. And a new Honda eu genset because of California blackouts last year and this and first times I ever need a genset in 65 years at my home(s) in California. Even turned my 93 year old father-in-law immigrant into a bit of a "prepper" (really my wife did, by talking about what we did with gensets and food storage).

    The other old saying... One (operating power source) is 'none'. Two (one spare) is one. Three (one running, two spares) is 'one spare'. Coast guard would install 3 redundant power systems at a lighthouse (in decades past, not sure now). And would "rotate" the operation of 3 engine systems to ensure all where functional.

    What ever you chose, "one" backup is not really enough. Choose two different brands/models--Then hopefully a common fault won't take the prime/backup 1/backup 2 all at the same time.

    Really depends on what you need the power for... Assuming LED lighting and a portable radio is the "minimum"--Even a 12 volt solar battery system works great--And a couple (3?) USB chargers for cell/USB power packs/etc.

    For short term 120 VAC power--A genset or two (with preserved gasoline, or possibly a propane genset) will allow emergency repairs while "other power" (solar, utility, etc.) power is not available.

    Obviously fuel (gasoline, diesel) eventually goes bad. And eventually you run out (no further fuel available if SHTF).

    Batteries have limited life (especially the small USB/Li Ion packs)... Back to looking for grandfather's (or now great grandfather's) hand cranked drill, hand saw, etc. to do repairs.

    The big loads always ended up being the fridge and freezer... Me, I was tending towards dried foods/shelf stable foods for longer term emergency supplies (if the panels/batteries/inverters don't fail, there is always the chance the compressors will).

    Now--To play with my wife--Talked about Pemmican as a stored food (nothing hi-tech there):

    https://en.wikipedia.org/wiki/Pemmican

    I don't see living in a "city/suburban" home for more than a few months (no water, no gas, no power, no sewage) before it become untenable (either my own living conditions, or those around me--Most who probably could not go 2 weeks without help).

    COVID has certainly changed much of life--No need for offices(?). Can telecommute for many jobs (certainly not all). Being on properly with well water/septic/etc. makes prepping "easier" and part of the daily lifestyle anyway (further from stores, fewer "utilities").

    -Bill
    You danced on a lot of subjects there. Yea, long term prepping has a lot of variables and unknowns. 

    Been investing in good sized lithium battery packs that are stored in the 40's during the summer - colder than that during the rest of the year. And chest freezers - they will be worth plenty if the SRHTF (R = really).

    Gensets are good for a couple months with enough fuel. I'm thinking years though - because why not? There is no rule that a catastrophe is limited to 90 days. 

    Decided that a 500 watt inverter is more practical. This has 900 peak watts. Can this easily be hooked up to my circuit breaker panel?  https://www.amazon.com/Victron-Energy-Phoenix-Inverter-VE-Direct/dp/B076TJKPFM/ref=sr_1_3?dchild=1&keywords=Xijia%2B3000W%2B(Peak%2BPower%2B6000W)%2BPure%2BSine%2BWave%2BInverter%2BDC%2B48V&qid=1598537879&sr=8-3&th=1

    If not I would be back to the original idea of running the house on 12AWG extension cords. Then I met a retired electrician who worked for $15/hr. During the depths of the Great Recession - great time to hire labor. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    It looks like that is an Amazon user comment about burning up when connected to home power... Don't worry there.

    From the manual:

    https://invertersrus.com/wp-content/uploads/2018/10/Phoenix-Inverter-250W-1200W-Manual.pdf
    The AC output is isolated from the DC input and the chassis. Local regulations may require a true neutral. In this case one of the AC output wires must be connected to the chassis, and the chassis must be connected to a reliable ground. Please note that a true neutral is needed to ensure correct operation of an earth leakage circuit breaker.
    Perfectly OK to let output float, or tie neutral to chassis/green wire ground is fine. If you are worried about safety--Using a GFI outlet--For use outside/near water.

    Personally, I did a bunch of 120 VAC extension cords for my in-law's. It was a giant pain in the butt.

    If you are looking for powering your main panel with backup power (inverter, genset), I highly recommend a retrofit manual transfer switch:

    https://www.homedepot.com/p/Reliance-Controls-10-Circuit-30-Amp-Manual-Transfer-Switch-Kit-310CRK/205793178

    The above is a 10 circuit transfer switch--Not cheap at $440. But not near as hard to install (bolt to wall, disconnect circuits to transfer, connect with wire nuts, and other end to respective breaker) vs a new subpanel or mains transfer switch--An expensive pain (usually). There should be lots of choices out there... And on the "genset" input--You can put an auto transfer switch of some sort (utility/inverter/etc.). Just leave the above manual transfer switch set to "generator"--And you do the auto transfer with ATS/MTS/AC inverter TS/etc.

    Decades ago, I put in a similar 6 circuit one... And that was not really enough circuits for my home. A remodel ended up putting in breaker for "everything". 10 circuit would have been a better choice. The home I grew up in only had 4x 15 amps fuses for the whole home--A different time.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    It would be far easier, perhaps even cheaper to buy an inverter than can readily handle both the genset and the circuit breaker panel.

    The circuit breaker panel being the more important of the two. I can buy a 48 volt charger for rare use. The sun is consistent here - 360 days/year of sun! Hence my sunny disposition!
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    At $176 I could buy the Victron as the #2 back up. Like a light house when common sense still ruled!
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    Thinking that if I seek an inverter that is readily used with a CB panel, I should look for wire lugs instead of 120V receptacles. Common sense. As for genset compatibility? Likely have to forgo that in a sub $700 inverter. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    If you are looking for SHTF type stuff... Do you really care about UL & lugs vs just getting an outlet blank and putting in conduit/Romex fitting to wire into the box (or mount a j-box on the "surface" of the inverter AC box)?

    Our host, it appears the least expensive inverter-charger is this guy for $1,440 (list):

    https://www.solar-electric.com/schneider-electric-sw-conext-inverter-4048-120.html

    for a 3.8 kWatt @ 48 VDC with transfer switch/battery charger/etc... Because, our host.

    There are other inverter-chargers for less money, but you are now looking at 12 or 24 VDC units.

    And, you may want to think about a 12 or 24 volt unit as your years down the road system. As your batteries fail (and they will eventually), you can reconfigure to a smaller bank (24 or 12 volt), and still run solar + battery + genset (if you can get fuel.

    Regarding gensets--You could always look at diesel and growing some sort of oil seed (trade stuff for oil)... Run a simple diesel genset on it (can be issues with fuel lines that are OK on real diesel, but turn to mush on other oils.

    Another issue--Not sure I would worry about an inverter charger in this case. Yes, they can be very nice (and some inverter chargers are much more programmable than the standalone chargers. But if you have no utility and no genset fuel--May not be worth it... Just have a backup 12/24/48 (whatever) AC battery charger if ever needed (and you probably already have lots of those).

    In any case, the old KISS principle (Keep It Simple xxxx) can come into play. Dedicating higher end inverters (like 48 volts) as SHTF spares--Being able to mix and match what you have on hand (vs not available anywhere at any price)--Not a bad things either.

    I still like the relay type semi-auto transfer switch. To AC input sources, default to one, switch to other when port 2 AC is "hot". Don't have to think about anything other than starting the genset, turning the spare #2 inverter, etc.

    Build with your own relay--Or get one from our host:

    https://www.solar-electric.com/pomaxpmautrs.html

    Already in a metal box with punch-outs. Also does include a delay to let genset get stable before hitting with loads.

    And how you handle your wiring... The "external" 10 circuit manual transfer switch (again, output of transfer relay into "alt input" for transfer switch--Can be "automatic" transfer based on relay (or more complex) auto-start without having to make subpanels and rewiring your home main panel.

    Or, just a pigtale cord from xferswitch input, and two (or more) AC outlets next to it (Inverter #1, Inverter #2, Genset #1, etc.). Just plug into the AC source you want (put a small LED light on each AC outlet so you know which one is hot.

    For people like me, getting close to the Old Codger's age--I suggest doing your engineering/conversion/installation now when things are easier vs 10+ years down the road when things become more difficult (aging), and/or stuff become hard to get (COVID-27 -- When Public Health runs our country and bypasses legislature, Governors/Presidents and Courts (courts/everyone differing to the "medical experts" in regulatory matters--Is not pretty already).

    Heck, as I am typing this--Convincing myself that I should probably convert to a 10+ circuit manual transfer panel soonish--Vs what I have to go through now to switch over to genset power.

    Is Prepping contagious like a computer virus?  :p

    -Bill


    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    The Schneider appears a good deal. But for $200 +/- more I can simply swap out my Outback 3648 (with another) with a 5 year warranty instead of 2 year. Indicating it may be built to last longer - in my mind anyway. Plus the Outback is optimized for 120V instead of 220V (Euro). But a lot more than I care to spend at this time. Hoping to find something that has been collecting dust for a decade and is half price - or so. Where is that Harbor guy? Other than Mexico - he seems the master of the deal with older inverters. He has been very quiet this year!

    A lot of your electrical talk is gibberish for the non-electrical by the way. 

    My new lithium batteries are optimized for 48V and represent a couple thousand invested. There is that.

    But the secondary system is 24V and I also need back up for that. That system powers three medium chest freezers at this time.  Planning to panel it up and increase it's work load very soon. Hoped to do it today but feeling lethargic.

    Yes - prepping is contagious. Every time I talk prepping to friends and relatives they start saying they should do it. Then they opt out for "You will take care of us". I plan to "take care" of another 2-3 or so. Takes 3 for 24/7 guard duties. Without guards we are simply prepping for those with the will and means to take what they want. 

    But if a relative brings a truck load of cattle? They can bring some friends and guns. I always have room for cattle and guns. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    You have questions about specific electrical terms... Please ask. That is why we are here.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    I'll just get a bolt in replacement rather than re-inventing the wheel. See my new thread about the newly toasted CC. Me and electricity don't always see eye to eye. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 32,800 admin
    Sorry Softdown, it looks like a moved a post you intended to keep in this thread (when splitting of another subject/poster). The post is below:
    -Bill

    softdown Solar Expert Posts: 3,412 ✭✭✭✭
    Come a little ways in terms of getting a back up - other than a cheap throw a way to keep frozen food viable for a couple weeks.

    Main inverter should have these features:
    Low frequency means greater surge and longer life
    Battery charger
    Readily hooked up to breaker panel
    Highly programmable low voltage cut off - though it seems like my Outback FM 80 allows that?
    Schneider, Outback, Victron and Magnum all fit the bill. My ONLY issue with my Outback is the 24/7 current draw. 
    Since 1500 watts with surge is more than enough, I hope to find a suitable inverter for sub $1000. That is the goal at this time.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SurfpathSurfpath Solar Expert Posts: 456 ✭✭✭
    Softdown
    i recently faced the same question, with 8 years on our OB VFX gear and the likelihood that our FP1-6 mate 2 would not play well with a new OB inverter.

    My solution was to I snap up a new GFX1448 at ~$1000, going cheap because they are now discontinued. 
    A high frequency inverter would have been an even cheaper solution but I don’t believe it would have integrated well into the flex power set up. 

    Even though the new backup inverter has a lower operating capacity compared to the original 3000 watt VFX3048, our loads have stayed low, and lower now with an inverter fridge.
    Plus the GFX has the 5 year OB warantee.
    -sp
    Outback Flexpower 1 (FM80, VFX3048E-230v, Mate, FlexNetDC) 2,730watts of "Grid-type" PV, 370 AmpHrs Trojan RE-B's, Honda 2000 watt genny, 100% off grid.
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    edited September 2020 #15
    Surfpath said:
    Softdown
    i recently faced the same question, with 8 years on our OB VFX gear and the likelihood that our FP1-6 mate 2 would not play well with a new OB inverter.

    My solution was to I snap up a new GFX1448 at ~$1000, going cheap because they are now discontinued. 
    A high frequency inverter would have been an even cheaper solution but I don’t believe it would have integrated well into the flex power set up. 

    Even though the new backup inverter has a lower operating capacity compared to the original 3000 watt VFX3048, our loads have stayed low, and lower now with an inverter fridge.
    Plus the GFX has the 5 year OB warantee.
    -sp
    Just returned from a trip. Is this GFX1448 still available somewhere? 

    Update:

    Outback GFX1448E 1400 Watt Grid-Interactive Inverter for 230 Volts AC 50Hz and 48 Volts DC

    This is not designed for US equipment. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • New_Mexico_WillNew_Mexico_Will Registered Users Posts: 107 ✭✭
    Reaching back a bit in this thread, if your inverter has ground/neutral bonding, can you simply remove the bonding screw from the main panel?
  • Raj174Raj174 Solar Expert Posts: 795 ✭✭✭✭
    edited September 2020 #17
    4480W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • softdownsoftdown Solar Expert Posts: 3,624 ✭✭✭✭
    Not designed for US market though. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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