a beginner's primer??

2»

Comments

  • VicVic Solar Expert Posts: 3,112 ✭✭✭✭
    72 dB at 23 feet is fairly LOUD.

    Some info the the Honda eu3000is,  below.  Note the noise specs  ...    FWIW,  Good Luck,  Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    edited July 24 #33
    As Vic says... You may find the 72 db rated Champion genset to be pretty loud for home use. If you don't have any neighbors and/or install in a sound proofed shed (with ventilation, etc.) then perhaps OK.

    The way we perceive sound is (more or less) logarithmic vs linear...

    If we measure the height of two people... One kid at 3 feet, and another at 6 feet. That is a big difference. However if we have a 30 foot building and and 33 foot tall building--Not hardly viable.

    With sound--For example, we "hear" a 100 Watt sound system as 2x louder than a 10 Watt system. And a 10 Watt 2x louder than a 1 Watt system (made up numbers).

    For sound in DB (decibels--A DB is 10xLog (power) -- Base 10 log). More or less, a generator that is 3 db louder or quieter than another genset, you can almost not hear the difference--Even though 3 db louder is actually 2x more sound power (i.e., 5 Watt vs 10 Watt speaker).

    And if you have a 10 db difference between two genset--That is almost a "night vs day" difference... Typically the +10 db genset will overwhelm the sound of the quieter genset (this is 100 Watt vs 10 Watt speaker).

     https://powerequipment.honda.com/generators/models/eu3000is (Honda specification link--FYI)

    So a 72 db genset vs 57 or 50 db genset:
    • 72-57 = 15 db difference (Honda at full load is 31.6x quieter or less "sound pressure" vs Champion)
    • 72-50 = 22 db difference (Honda is even quieter 158.5x quieter or less "sound pressure" at 25% load--Don't know Champion numbers)
    Just an FYI--+/- 2dba is usually within the margin of error for these types of mesurements.

    These are (relatively) huge differences in noise level. And note that both the Honda and Champion you link are measured DBa @ 23 feet (some mfg. "cheat" and use a longer distance).

    The Champion generators have had some good reviews here (reliable, long life). And the open frame inverter-generator you linked is a TSW (true sine wave) with 3% THD (total harmonic distortion)--A very good thing. Many less expensive inverter-generators (the smaller ones?) are MSW (modified square/sine wave) type with something like 25-30% THD.

    https://www.championpowerequipment.com/product/100520-8750-watt-open-frame-inverter/

    Watch fuel consumption numbers--Make sure you compare:
    Champion’s reliable 420cc engine produces 8750 starting watts and 7000 running watts, and runs for 10.5 hours at 25% load when the 4.2-gallon fuel tank is full.
    • All Power America 3,500 WAtts
    • Without 240-volt
    • 3500-Watt peak
    • 3500-watt gas powered portable generator
    • 68 decibel noise
    Honda eu3000is:
    2,800 Watt rated load
    Run Time per Tankfull 6.9 hr @ rated load 19.6 hr @ 1/4 load
    Fuel Tank Capacity 3.4 gal.
    • Champion:
    • 10.5 hours * 0.25 rated load * 7,000 Watts * 1/4.2 gallon tank = 4,374 Watt*Hours per gallon (1,750 Watt load)
    • All Power 3,000 watt continuous load:
    • 8 hours * 0.50 rated load (typical is 50% of load for fuel consumption) * 3,000 Watts * 1/4.2 gallon tank = 2,857 Watt*Hours per gallon (guess 1,500 Watt load)
    • Honda eu3000is:
      6.9 hours * 1.0 rated load * 2,800 Watts * 1/3.4 gallons = 5,682 Watt*Hours per gallon (2,800 Watt load)
      19.6 hours * 0.25 rated load * 2,800 Watts * 1/3.4 gallons = 4,035 Watt*Hours per gallon (700 Watt load)
    Typically, standard residential generators are rated at 50% load (below 50% load, gallon per hour fuel usage does not drop much).

    Inverter generators are typically rated at 25% load for fuel usage (I would guess this is their "knee" in the fuel usage curve).

    The Champion and Honda inverter-generators are pretty close in fuel consumption... You would have to look at your home/pumping power usage (average Watts) to see which generator is better sized for your loads (over sizing a generator can waste lots of fuel.

    Looking at running the All Power America at 50% load--At 1,500 Watts it delivers much less energy (Watt*Hours per gallon of fuel) at 50% rated power (1,500 Watts). And if your average loads are less than 1,500 Watts, it will waste any more fuel (at 25% loading, run time will probably be only a little better than 8 hours per tank--Gallons per Hour of fuel usage at less than 50% typically does not drop much). Just as a guess, you will get around (1/2*2,857WH/G= ) ~1,429 WH per gallon (about 3x more fuel burn for 750 Watt load).

    A good quality "plain" genset running >50% rated load will generally be pretty fuel efficient and can even be better than an inverter-generator...

    In the above examples--I would guess that the fuel usage (Watt*Hours per gallon) is very similar between the Champion vs Honda--So I would not use that as a major factor in choosing.

    However, the 72 DBA Champion vs 50-57 DBA Honda may be a major factor.

    I would suggest to stay away from the All Power genset if you plan on running many hours per day and/or per year... It will probably use almost 2x more fuel for the same loads as the Champion or Honda inverter-generators--Especially if operating at 1,500 Watts or less average load.

    For a typical home that is conserving energy (not really that large of AC loads--Suggest less than 1,000 Watts average when genset is running?). 4 Gallons per 8 hour day @ 50% or less loading (APA genset) vs:
    • 8 hours per day runtime * 1/19.6 hours per tank * 3.4 gallons per tank = ~1.4 gallons per 8 hour day for Honda (and ~Champion)
    • (4 gpd - 1.4 gpd) * $4.00 per gallon (I am in California...) = $10.40 "extra" fuel costs for APA genset @ 8 hour day
    • And if you want 24 hour per day electricity (ice storm, wife unhappy)--A that $10.40 per 8 hours adds up quickly:
    • $10.4 per 8 hours "extra fuel costs with APA" * 3 (for 24 hours per day) * 7 days to get power restored = $218.40 "extra" APA fuel costs for a week of backup power in gasoline costs (again at $4/gallon "California gasoline costs")
    • 4 gallons per 8 hours * 3 (24 hours) * 7 days = 84 gallons estimated APA one week fuel usage (24 hours per day)
    • 24 hour runtime * 1/19.6 hours per tank * 3.4 gallons per tank * 7 days = 29 gallons of fuel for Honda/Champion one week fuel usage (24 hours per day)
    A NOTE: I am not in this business (generators or solar power). I am using publicly available information to "model" the operation of various items we have talked about here. I have links (or used your links) to get the information and have shown my work (aka math).

    I do not "recommend" any particular brand or model(s) of hardware (generators or solar equipment) simply because this stuff was never my job and I do not have years of experience with any one piece of hardware. Any observations I may have made have been pretty much based on what forum members' have related here.

    Could you purchase an APA genset for a good price, and get many years of life from it and be very happy. And you bought a Honda that tanked after 100 hours of use--It could happen. I suggest that you read reviews and do a bit of math/modeling based on your needs--And as I suggested before--Possibly and rent a unit before buying.

    This is your money--Not mine. And I do not want to see you waste/lose/burn it. 

    The above example is assuming an 8 hour work around the house/pump water/etc. day and a 7 day run times (power failure after an ice storm) on California priced gasoline... Your home, your energy needs, your money, your choices.

    Everything clear Matthew (and everyone who reads the forum)? Using math to help make economically sound decisions here (aka "penny wise, pound foolish" saying).

    -Bill "I am perfectly happy here and enjoying the discussions" B.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    I also should add... All models are approximations and full of assumptions.

    Are the numbers above "accurate/exact"? Probably not.

    Are they close enough to be "useful"--I think so.

    Always check the assumptions/math... There may be mistakes in either/both

    -Bill "I am not anywhere near perfect" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • geosierranevadageosierranevada Registered Users Posts: 41 ✭✭✭
    Use aviation gas, about 105 octane for low usage generators. It will last over a year. It's pricy but you will not have to use stableizer or drain the fuel. I use it on my chainsaws. Also check out the Harbor Freight predator generators, they are alot cheaper then the Honda and very comparable.  We live off grid and have 5 generators, 12kw - 5kw - 4.5kw welder generator - 3kw Honda is and 1kw .   Good luck with everything.   George
    Off grid for 18 years. 5KW panels, Trace sw4024, Bergy XL1 wind generator, GB forklift battery.  3 SQF 2 well pump, 12kw back up gen.  Not easy living in the wilderness but it keeps you busy
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Be a little careful about 100 LL av gas... While it is lower lead than standard Av gas, it is still an issue for various engines:

    http://www.aviation-fuel.com/pdfs/avgas100llspecsastmd910_2011.pdf

    100 LL did not have as much lead as standard 100 octane Av gas--And the older aircraft engines did sometimes have issues with valves sticking because of not enough lead for valve lubrication (had a friend that temporarily loss engine power over the Rockies decades ago when 100LL came out).

    However, it is still more lead than is in today's unleaded gasoline. Any lead will clog catalytic converters--And CARB (California Air Resources Board) compliant generators (probably?) have catalytic converters which will be damaged by the lead.

    Is this an issue? Don't know (more unburned hydrocarbons, CO, NOx--stuff for smog). Will an end user/owners even notice (plugged converter)? Don't know.

    https://www.nettinc.com/wp-content/uploads/2016/06/Honda-small-engines-3-way-catalytic-converter.pdf
    https://www.catalyticexhaust.com/product/3-way-catalytic-converters-mufflers

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • thookthook Registered Users Posts: 23 ✭✭
    @BB.
    so, i met a friend of my wife's on a chat list who's familiar with solar use on a farmstead. something that had not occurred to me until tonight were solar panels with microinverters running AC voltage directly (no batteries!!) to standard 120/240v appliances...ie. a pump. probably ya'll have mentioned these above, so i need to reread here. but, it got me to thinking...some more <<grin>>

    the way he explained microinverter set ups sounds more simple and likely less costly than DC arrangements (given DC wiring heft, batteries, and multiple gadgets) we've talked about thus far in this thread. however, i'm rethinking along this line mostly because my damn electric bill is already so high as it is...even being on a co-op. and, that may be why it's so high. i don't know. $180 something last month!! anyway, tossing around the combining elements of operation here as follows:

    solar/microinverter to pump for daytime/ ideal weather condition use
    grid power for night time and less than ideal sun conditions (timer/manual switching with DPDT arrangement somehow...maybe?)
    generator for either solar system failure or grid power outage

    again, i need to reread the thread, but any opinions ya'll care to share would be lovely :)

    ps. if a microinverter thing would work simply enough on the pump, i'm wondering down the road (next year?) about my water heater. the room it's in has a nice angle, a fair amount of sq footage, and sun exposure just as the well house does. not too hard up on this possibility, but if i could...why not? i already only run it minimally with a manual switch between the breaker and heater. 

    pps. if i could knock my bill down $60-$80/month, that'd be $700-$900 a year. 

    as always, thanks :)
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    To run 120 VAC power without a battery bank (only when the sun is high in the sky), there are several options that I have read about (I have not used them, so this is just a pointer):

    SMA with their "secure power" GT inverter... They can supply 120 VAC power during the middle of the day.

    https://www.solar-electric.com/sma-sunny-boy-3-0-1sp-us-41-grid-tie-inverter.html

    I have also read Must brand of AC inverters... They are designed to run with a battery bank, but they do have models that can run 120 VAC power without a battery bank:

    https://www.mustsolar.com/

    But this is not an "optimum" way of operating... You only harvest electricity when you have an AC load plugged in and operating during the middle of the day (i.e., when the microwave is running).

    And just powering a microwave is not going to save you much money. Yes the microwave uses a lot of power (something like 1,200 Watts on high power)--But you might use it 20 minutes a day:
    • 1,200 Watts * 20 Minutes * 1/60 minutes per hour = 400 Watt*Hours per day = 0.4 kWH per day
    • 0.4 kWH per day * $0.20 per kWH (guess about your power costs) = $0.08 per day of power
    • $0.08 per day * 30 days per month = $2.40 per month to run a microwave.
    If you really want to save energy--The best bang for your buck is to get a GT Inverter system installed. You have solar panels->GT inverter->AC main breaker panel. Get a city permit (if required) and approval by your utility (you do this first, then buy parts/install system--Or go with a local company that installs GT power systems) and install.

    The GT inverter takes all the power the solar panel can harvest during the day, and supplies it to your main AC panel. That power powers both your local AC loads, and can slow your utility meter down, or even spin it backwards. The whole GT solar system is "transparent" to you once it is running... The only thing you will see is a reduction in your utilty bill.

    Whether GT Solar can save you money depends on your utility policies and power tarrif plans for GT solar. Not all utilities allow GT solar. And some locations/utilities have power plans that do not make economic sense (Hawaii, Nevada, some rural co-opp utilities, etc.). It is pretty political. Government wants to "go green" and utilities want to make money and have a stable/reliable grid power system.

    Just as an example say you want to save $80 per month, your utility charges $0.20 per kWH (some places more, some places less, and the rate plans are getting "more complicated" in some areas with time of use charging and paying wholesale only for power, etc.). And guess that you have an average of 4 hours of sun per day over the year. The basic math looks like.
    • $80 per month savings / 30 days = $2.67 per day power savings
    • $2.67 per day / $0.20 per kWH = 13.35 kWH per day
    • 13,350 Watt*Hours per day * 1/0.77 GT solar system efficiency * 1/4.0 hours per day average sun = 4,383 Watt array
    • 4,383 Watt array * 0.77 GT system eff = 3,375 Watts = 3.4 kWatt minimum rated GT inverter system
    GT solar works. Works well/transparently. And is the simplest/lowest maintenance solar power system out there. And is the only system that can and does save you money (your actual power costs are usually less than $0.10 to $0.05 per KWH roughly--Cost to install/10 your system life/kWH produced).

    Down sides/issues with GT solar:
    • Does your utility allow GT solar (not all do)
    • Does your utility give you a good rate plan for GT solar (typical plan used to be your kWH generation deducts from your power bill at $0.20 per kWH/retail cost. If you generate more than you use during summer, goes in "the bank". During winter when you generate less power, you "draw" from the bank. At the end of one year, you either pay the negative balance in the bank, or a positive balance is set back to zero).
    • Many utilities have rate plans that don't work as above. And most plans are less "solar customer" friendly--Reality is that old plans were subsidized by other utility customers and government. Today, many companies still need to make money from GT solar customers, so the savings/rate plans are not as cost effective.
    • Many customers choose to install solar panels on roof--Usually you need a new roof before installing solar (so you don't have to take off array 10 years to replace roof). Old roofs can leak. And many GT Installers do not do a good job with flashing/sealing roofs--And cause leaks.
    • 10 years down the road, the utility may change rate plans and cost you some of your savings.
    • Standard GT Solar only works with utility power. If power goes down (ice storm, car takes out pole, etc.), the GT Solar shuts down too.
    • Secure Power backup systems will supply a separate 120 VAC outlet for you to plug into. Some systems require you to push a button to turn on Secure Power (not automatic) and you are supposed to plug your AC load(s) into the second outlet (again not automatic). Secure Power only works if there is lots of sun (9am-3pm roughly) and your AC loads are less than the solar array can supply (at 8:30 am, your 1,200 Watt microwave uses more than the 500 Watts your array can supply in the airily morning--Shuts down Secure Power until microwave load is turned off).
    • You are paying for your next 10 years of power savings up front. $4,000 Watt array * $5 per Watt installed price (just a rough estimate) = $20,000 up front costs. You may be saving $80/Month, or $960 per month--But it is going to take you a number of years to "break even".
    • Or you can get financed/leased systems for solar--Contracts and paperwork can be complicated--And if something goes wrong--Not always clear what happens next (do you still need to make payments, will they remove your system and fix roof, will they fix the system or not, etc.)
    • If your utility power "goes away" (no longer services your address, the world ends as we know it, etc.), the standard GT Solar system will not work. Secure Power may be a pain to use and only run your fridge/freezer during the day (GT Solar is not really a "prepper" solution.
    • Even a full hybrid power system (solar+batteries+inverter+plus genset) has it drawbacks. Expensive battery bank which requires maintenance and eventual replacement. Electronics may need replacement after 10+ years. Solar panels are glass and easily broken by wind blown derbies and rocks. Gensets only work if you can get fuel (or with diesel, you grow you own oil seeds).
    I am a big believer in conservation. Insulation, energy efficient appliances/lighting/well pumps/etc., and turn stuff off when not used.

    Look at your power bill... $80 / month / $0.20 per kWH = ~400 kWH per month. The typical USA home energy usage is around 500 to 1,000 kWH per month. What is yours?

    I suggest that full conservation and using other fuels (propane, wood, etc.) for heating/cooking/etc.--You could get down to near 100 kWH per moth (3.3 kWH or 3,300 WH per day)--Which is a pretty practically sized/cost full off grid solar power system (LED lighting, standard refrigerator, washing machine, LED TV, laptop computer, cell phone charging, "solar friendly" well pump). This not "home on the prarie"
     life--But does require a lot of conservation on the family's use of electrical energy.

    And if you stay on utility power--That is a ~$20 per month power bill (potentially).

    With utility bills--The details matter, a lot. Look at your bill today and figure out your actual energy costs ($/kWH) and any connection fees (i.e., $10 / month connection and billing fees). And look around your home at today's energy usage.

    Get a Kill-a-Watt type meter and see how much energy your major 120 VAC appliances are using today. New appliances use less? Changed to LED lighting everywhere? Use laptop vs desktop computer, etc...

    https://www.amazon.com/s?k=kill+a+watt+meter&ref=nb_sb_noss_2

    There are also "whole house" energy monitoring systems (here is one link, many others out there too--And some utilities now offer online energy monitoring from their website):

    https://www.theenergydetective.com/

    Look at the problem (energy costs, backup power, etc.) as a whole. Don't fixate on one solution only. And do the paper design(s) first before you jump in with both feet and start buying stuff.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • thookthook Registered Users Posts: 23 ✭✭
    @BB.
    i'm gathering micro inverters are not an off grid thing? i've seen 240v MI's (which i'd need for the grundfos), but only see they're grid tied...which i'm gathering is what you mean by GT? i mean, if they're exclusively grid tied, well that's kind of missing the point...lol. i was looking for a possibility if/when the power goes. my wife's friend made it sound so simple. but, then i don't know the questions to ask right now until i learn more
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    There are central GT inverters--A bunch of panels connected to one GT Inverter, typically mounted on a wall at ground level. And there are micro GT inverters--One (or two) panels connected to one inverter (and the micro inverters are mounted on the panels/roof/racking).

    There are micro inverters that support secure backup power (at least I have seen the advertising)... But I do not know exactly how it is done (I guess it is available now). Still has the issue of only supplying AC power when the sun is up (i.e., the middle of the day).

    There are advantages and disadvantages to both types of GT Inverters. But both do pretty much the same job.

    If you only need AC power from 9am to 3pm or so, during sunny weather--GT Inverters with backup (secure power) are available that do that.

    If you want power 24 hours per day--Then you need batteries and/or a backup genset.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • thookthook Registered Users Posts: 23 ✭✭
    i had not seen some of the replies made. didn't know they were there. i'll respond more later. in short, though, if the micro inverter/direct solar AC set up is all grid tied, that ain't gonna work, either. darn it..
  • thookthook Registered Users Posts: 23 ✭✭
    edited July 31 #42
    i'm back. once again, just want to thank everyone for the advice and input. after going over this thread and thinking about everything the past week, looking at all options, and considering costs i've determined to build a couple of solar generators replicating something like this within as much as i need. 

    https://cuttingedgepower.com/products/rebel#mz-expanded-view-654282158705

    so, say i put the equivalent equipment in, i'm just not sure about selecting panels to charge the generator. i've seen set ups where people make a portable panel array. i'm thinking in that direction since the sun exposure can shift from season to season, but also as trees grow in certain areas around, i will want to adjust where panels are accordingly. the other thing is, going with a couple of portable gen units, i can build just one array to charge the two. have one charging while one is in use.,, something like that. but, how much panel power would i need? how do i come to some determination on that? maybe a couple of 200 watts panels wherein they're hinged where they join so i can fold them over to port around? would 400 watts of charging be enough? two 400 watt panels?

    i also decided to do this so that either generator can actually be in the house/well house during cold weather. i'll still have the gas honda as a back up, but i know how gas engines go. troublesome starting sometimes or if i have to leave the house for the day

    this generator in the link above as one of those all in one MPPT units. i'm not sure what i'd need to get to power things. i'm looking ampere time lith/iron/phos 200ah batteries...one in each generator. but, since i want to make at least one of the gen's 240v capable (as well 120v). not sure what MPPT to get. so far i can only find them for 120v.
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Even though you can get "all in one units"--At least at first, look at everything as a separate black box and understand what capabilities each box has... And always start with your loads--Without knowing your loads, you have no idea of what you need to run them.

    I would love to get a 25kWatt genset on a trailer--But it is crazy large to supply my home and would suck fuel like no tomorrow (something like 0.6 gallons per hour of diesel just running no load or 7+ gallons per day:

    https://bossltr.com/product/25kw-portable-diesel-generator-trailer-mounted/

    The link to cutting edge power--They have an 8,000 Watt @ 12 VDC inverter. That is not (I suggest) a practical configuration (that is almost 900 Amps @ 12 VDC at full load).

    As a very rough starting point... Whatever is your "peak inverter wattage", I would suggest your solar array will be around that wattage (1,000 Watt inverter, 1,000 Watt array; 8,000 Watt inverter, 8,000 Watt array). If you want 4,000 Watts for 5 hours for 2 days of storage), you are looking at (at the very least) 4,000*5=20,000 WH of battery. 20,000WH/48v=416 AH @ 48 Volts (and typically 2x that size in reality).

    Vs an efficient genset and 4-5 gallons of gasoline for the equivalent 20,000 WH of battery storage.

    MPPT is just an interface "type" for solar panels. It is more efficient than PWM type interface (for various reasons)--Sort of like an automatic transmission on a car vs a car with 1 speed transmission... The Automatic works over various speeds and loads pretty efficiently. The 1 speed gear box, if exactly matched to the load/speed you drive works well, but is otherwise pretty clunky for everyday use.

    Do you have the Watt*Hours per day you need for each of the system loads? And what your use/expectations are?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • thookthook Registered Users Posts: 23 ✭✭
    BB. said:
    Even though you can get "all in one units"--At least at first, look at everything as a separate black box and understand what capabilities each box has... And always start with your loads--Without knowing your loads, you have no idea of what you need to run them.


    As a very rough starting point... Whatever is your "peak inverter wattage", I would suggest your solar array will be around that wattage (1,000 Watt inverter, 1,000 Watt array; 8,000 Watt inverter, 8,000 Watt array). If you want 4,000 Watts for 5 hours for 2 days of storage), you are looking at (at the very least) 4,000*5=20,000 WH of battery. 20,000WH/48v=416 AH @ 48 Volts (and typically 2x that size in reality).

    Vs an efficient genset and 4-5 gallons of gasoline for the equivalent 20,000 WH of battery storage.

    MPPT is just an interface "type" for solar panels. It is more efficient than PWM type interface (for various reasons)--Sort of like an automatic transmission on a car vs a car with 1 speed transmission... The Automatic works over various speeds and loads pretty efficiently. The 1 speed gear box, if exactly matched to the load/speed you drive works well, but is otherwise pretty clunky for everyday use.

    Do you have the Watt*Hours per day you need for each of the system loads? And what your use/expectations are?

    -Bill
    thanks, bill. i don't have the usage data,  yet. tried to borrow a meter, but no dice. probably better i just have my own, anyway. just haven't gotten as far as getting one. i do, however, have an idea of how big either generator needs to be at minimum going by diy systems people have built for their own needs. so, that's a start in the direction of research on panels. 
  • thookthook Registered Users Posts: 23 ✭✭
    turns out we have a watt meter that will probably be sufficient to monitor any 120v appliances, but it won't do 240v. i did find this, though....

    https://www.amazon.com/Measuring-Electricity-Frequency-Voltmeter-Household/dp/B082XX9V5S/ref=sr_1_29?dchild=1&keywords=killawatt+220v&qid=1629312624&sr=8-29

    it's not a brand of electrical equipment i'm familiar with, but are most things like this adequate for the purpose? i need to get readings from the well pump. 
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    A bit of a mixed bred that meter. A US 120 VAC @ 60 Hz plug on one side, and multi-country socket on the other side.

    Written as a 220 VAC @ 50 Hz unit... But does seem like it would function on any "normal" 100-240 VAC circuit.

    Of course, you would now need to wire up a 120 VAC socket as a 240 VAC socket (not a great idea--But I have done worse)... And the unit appears to only rated for 10 Amps... A typical Kill-a-Watt meter is rated for at least 15 amps.

    For a well pump, 10 amps is probably too small (I loaned a kill-a-watt meter to a friend with an 120 VAC air compressor, and the starting surge "fused" the metal "resistor" strip--So they typically do not have a lot of room for surge current capabililities).

    For larger loads (240 VAC, higher current, etc.) you really need to look at a "whole house" monitor (probably with multiple measuring circuits so you can see what is laundry, hot water, central heat/air, water heater, etc. loads).

    Or get one and move around, or a few of these cheap kWH meters from Amazon or similar (lots of choices on Amazon and EBay):

    https://www.amazon.com/CrocSee-CRS-022B-Frequency-Multimeter-Transformer/dp/B07K3S4K9L

    These are $16 to $20 each... ($16 is a solid transformer you have to put the free end of wire through; and the $20 has a "clamp" transformer--Easier to install/move around--Don't have to disconnect "hot wire" to wire through transformer).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Sign In or Register to comment.