How to run inverter into electrical panel

jrfuzz35
jrfuzz35 Registered Users Posts: 3 ✭
edited April 2020 in Solar Beginners Corner #1
I have the following inverter. 5kva hybrid 48vpure sine wave inverter with charge controller. 

In my camper, the system is off grid. Using solar panels (2-315w) and a 4-100ah 12v batteries ran in series. No other power source, as Colorado is always sunny. The inverter does have an AC input to plug
into a outlet if I wanted to charge the batteries that way, but it is not a necessity to me.

It’s the 5kva, 48v. Model. It has 3 wires as the AC output of 230v. It lists the 3 outputs as ground, leg or hot, and neutral. But I tested the wires. And the hot is 117v, and the neutral is 113v. Testing that both are a 110v hot? 
I  am trying  to run this into a electrical panel, and run my  trailer camper with receptacles At 110v. Maybe just 2 breakers is all I need to run a few lights, 5 outlets, 

I am Trying to figure out if the neutral is actually a hot, how do I hook it up? Do I ru. The 2 hits into separate circuit breakers, connect all the grounds to the left bus bar, and ground it to the chassis. And not use a neutral? If it doesn’t actually have a neutral output, does that mean  it has an internal Neutral, and I should bond my neutral to ground?  Or should I connect all the neutrals on the right bar, and then run it to the AC input neutral or hot, and make a loop so any overpower returns to the inverter? I am really confused by the neutral situation. I don’t want to screw anything up and fry myself or the system. Any advice would be greatly appreciated in advance!!

the manual doesn’t say anything about this, and I’m having trouble finding anything online. 

Help!!!! 😂

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Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #2
    Welcome to the forum 

    You need to establish what you have before connection is made. Going on information provided  it would appear it's a single phase 230V inverter, not a split phase, if this is the case it alone cannot support 115V. The three output connections, ground, leg and neutral would indicate this, the neutral is likely bonded internally to the ground, to establish a neutral or no potential difference between it and ground. 

    Can you post the specifications or a link to the make/model, some pictures would also be helpful. 

    Between what points were the voltage readings of 113 and 117V taken 


    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #3
    It is also possible that the 5kWatt inverter is an MSW inverter? If true, then make sure you do not have a ground bonded AC neutral in the trailer (main panel, backup genset, etc.). Having the DC ground bonded (typically negative ground) and an AC neutral to ground bond too, will generally "smoke" an MSW AC inverter--In general, only PSW/TSW AC inverters support a ground bonded neutral.

    Also, a 5 kWatt inverter is way overkill for your 48 volt @ 100 AH battery bank and 630 Watt of solar panels... Without knowing anything else, you would be looking at a ~500-1,000 Watt AC inverter (and probably 12 volts would be fine, if you have any other needs for 12 VDC power in the RV (typically, RVs are wired to support 12 VDC lighting, fan, water pump, etc.).

    A 5 kWatt AC inverter would take your battery bank from full to dead in 30-60 minutes with a 5,000 Watt load.

    I suggest you backup a moment and figure out what it is you want your AC power for (lights, laptop/tablet computer, cell phone charging) or what... For off grid solar, particularely smaller systems, conservation of energy is critical. Use the smallest/most efficient loads you can, keep usage to a minimum (only run when needed, turn off when not).

    If you need to run other larger loads only occasionally (Skill Saw, AC Well/Water Pump to holding tank, Clothes Washing Machine, etc.) a few hours a week--A genset + gasoline is probably going to work much better (and cheaper) than your present solar system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • jrfuzz35
    jrfuzz35 Registered Users Posts: 3 ✭
    #4
    Hey guys thanks!! To clarify here is the model inverter from eBay, 

    https://www.ebay.com/itm/283730629248

    let me know what you think? Is it possible to use a step down transformer? Or any way to convert it? The 4-100 ah batteries seem to be fine, I have it Currently 
    connected to a power strip and running a Samsung tv & MacBook, both have a range of 100-240v. and it seems to be fine? Is this okay? I’m def new and learning. Here’s the picture of how the power strip is connected to the AC output, here is the specs of the solar panels (I have 2), and the input and output of the inverter, and the specs of the hybrid inverter charger. 

    Batteries are 100ah lead, and 4 ran in series. 

    Let me know what you think! Thanks again! 🙏 





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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #5
    Be a bit careful with power strips... Some power strips have internal surge suppressors, and if you are using standard North American 120 VAC plugs/power strings, the surge suppressors can "trip" and short out the 230 VAC output (behaves as 230 VAC surge).

    The inverter looks to be a PSW/TSW type:

    https://www.aliexpress.com/item/33047139947.html (assuming this is the unit)

    So a ground bonded neutral would probably be fine (check the manual).

    Given that it does "everything" for $300 (solar charge controller, AC inverter, and AC Battery charger--Just about any other solution is going to cost more money than this unit. But it is a 230 VAC AC inverter--So, a transformer is the only way to get 120 or 120/230 VAC out of it.

    A small transformer will power your smaller loads. A larger inverter to power the bigger loads will probably cost more than your inverter/charger and will waste more energy.

    Watch the battery bus voltage... 51 volts is about the "resting voltage" for a fully charged Lead Acid Battery... But low for float (13.2 to 13.6/52.8 to 54.4 volts float) and obviously not charging (14.4 to 14.8 volts/57.6 to 59.2 volts charging). You don't want to under charge / over discharge the battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • jrfuzz35
    jrfuzz35 Registered Users Posts: 3 ✭
    #6
    Yup that’s the one! A friend drew me this, does this seem correct? 
    If so, I have a transformer of rated for 2,000 watts, would that work? And where/ how to I stall it?

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #7
    Jrf,

    That AC diagram is fine (in my humble opinion)... And the one or other grounding wire is generally correct... I would only have the "right one"... The idea is single point grounding. The reality is if the inverter is bolted to the RV Grounded metal frame, you have multiple grounding points anyway.

    The Battery ban, would also have a ground bond wire from Negative battery bus to the "single point" chassis ground "bus"...

    You will follow the NEC wire ratings for Breakers (fuses)? Here is a simplified NEC rating table:

    https://lugsdirect.com/WireCurrentAmpacitiesNEC-Table-301-16.htm

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #8
    A 2 kWatt transformer will work... Note that it will use ~100-200 Watts (guess) by itself.

    Where to install it... Do you want a 120 VAC and a 230 VAC or 120 VAC only power?

    A 5 kWatt inverter will take close to 50 to several hundred watts just "turned on" (Tare Losses)--Guessing.

    Do you have a DC current clamp DMM so you can measure the "tare current" for your AC inverter? Some thing like one of these (just suggested links for you to start your research):

    https://www.amazon.com/UNI-T-Digital-Current-Capacitance-Multimeter/dp/B0772FYF5M
    https://www.amazon.com/gp/product/B019CY4FB4

    I truly worry that your existing system is a severely "unbalanced" design. A huge AC inverter and (practial for an RV) solar array and battery bank...

    I suggest that you look at a 400-850 Watt AC inverter (maximum) based on your existing Battery Bank capacity... Those typically only use ~6 Watts of Tare (loss). And would work very nicely on a 12 volt battery bus (you can now find smaller AC inverters for 12/24/48 VDC battery bus voltages). Look around for an AC inverter (watts, dc input, ac output, features, etc.) that meets your needs.

    And for the battery bank--You can rewire from 48 VDC (4 series x 1 parallel string) to 24 volt (2s x 2p) to 12 volts (1s x 4p).

    Again, for most RVs, 12 volt battery buses are usually a good fit for 12 volt RV appliances, power adapters, HAM radios, RV water pumps, etc.... Whatever your energy needs are.

    If you have AC loads--A Kill-a-Watt type meter is a good place to start to size your loads:

    https://www.amazon.com/s?k=kill+a+watt+meters

    Just to give you of how much AC power/energy you can use. Lets say you discharge your battery to 75% SoC (2 days storage, 50% max discharge) to 50% SoC (1 day storage, 50% max discharge):
    • 4x 12 volt batteries * 100 AH each * 0.85 AC inverter eff * 1/2 days of storage * 0.50 maximum discharge (for longer battery life) = 1,020 WH of store 120/230 VAC power (1,020 WH per day for two days of "no sun")
    • 4x 12 VDC * 100 AH * 0.85 AC inverter eff * 1/1 day storage * 0.50 max discharge = 2,040 WH per day
    For a full time off grid system, I would suggest the 2 days storage and 50% max discharge (1,020 WH per day)... Using more energy per day (2,040 WH) every day is pretty difficult without over discharging the battery bank.

    And how much energy can you harvest per day... Just using a 630 Watt array mounted flat to roof around Denver:
    http://www.solarelectricityhandbook.com/solar-irradiance.html

    Denver
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a horizontal surface:

    JanFebMarAprMayJun
    2.41
         		3.27
         		4.49
         		5.42
         		6.28
         		6.70
     
    JulAugSepOctNovDec
    6.35
         		5.68
         		5.03
         		3.90
         		2.67
         		2.18
     

    So, full time off grid all year round (genset backup?). Or just non-winter energy... To demonstrate, a well designed/balanced system would harvest around (picking Feburary for "break even" month) 3.27 Hours of sun per day (long term average):
    • 630 Watt array * 0.52 end to end AC off grid system eff * 3.27 Hours of Sun per day = 1,071 Watt*Hours per day
    During deep winter, less solar harvest... Mid summer, >5 hours of sun per day--Lots more energy harvest (long term average).

    Just to show you how an "oversized" AC inverter can "waste energy"... Say 50 Watt Tare loss (guessing) for your inverter. And you want to run it 5 hours per day:
    • 50 Watts * 5 hours per day = 250 WH per day losses
    That is about 1/4 of your daily energy harvest (and worse, if your inverter uses more power)... Again, just guessing and setting up and example.

    A  smaller inverter (300-600 Watt range) would probably closer to 6 Watts Tare:
    • 6 Watts * 5 hours = 30 WH per day "tare loss"
    Much less "wasted power".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #9
    Do I read on the label, that it's a 50hz inverter ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #10
    Appears to be programmable between 50 and 60 Hz....

    And really inexpensive (at least for now--After possible USA tariffs, trade war, and ConVid--Who knows).

    3+ Decades ago, switching computer power supplies used to be $0.50 in wholesale quantities (relatively small mini-mainframe mfg of the time)...

    This inverter/AC charger/MPPT charger hybrid unit--Something like $0.06 per Watt. Unreal.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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