Generator procedure?

stmarstmar Solar Expert Posts: 362 ✭✭✭
I wired my AC2 (Generator) connection but have not run the generator through it. Looks like winter is right around the corner so thought I should test it out. I don't want to make any mistakes so would appreciate a review by more knowledgeable users. This is what I have done up to now:

1. AC2 is wired with a 12 gage wire
2. Max charging amps is set to 12 amps

I set the AC2 input amps to 12 amps also to match generator correct?

Is there a sequence of steps to start the generator and apply it's power to the inverter?
It will be a manual start and my inverter has a Generator Mode (Menu 2) and the only user setting is Off Auto On Eq. Right now of course I have it Off since I am on grid. So I turn off the grid AC1, turn on the generator and then go to the Menu2 and chose On? Is there anything I need to look out for? Thanks, just nervous about first time. Did not know if generator should be on before or after I chose On with the inverter.

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Generator procedure?

    Input Amps is the maximum current to be drawn from the generator for both charging and loads. Charging Amps is usually lower than this. The EU2000i can just about handle 12 Amps max.

    Start gen, make connection to inverter. I don't know if the Xantrex will autodetect power on AC2. If not you'll have to turn it on; gen power should be available first otherwise it will be looking for something that isn't there. Reverse procedure to shut down: take inverter off gen power, then shut off generator.
  • stmarstmar Solar Expert Posts: 362 ✭✭✭
    Re: Generator procedure?

    Thanks, that is what I needed to know, gen on first. Inverter has a manual gen start and that is the mode I will use. If this storm is as bad as they say we will be using all of our goodies to keep the power flowing.
  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: Generator procedure?

    I recently installed and commissioned my Xanterx XW4024wbackup system and I just days ago checked my Gen assist feature and it went as follows;
    During a load test I wanted to check the Gen assist feature of my inverter so I set it up to assist when the load on the generator exceeds 3.3kw.
    With my inverter inverting approximately a 600 watt load I started MY GENERAC XL4000 and let it stabilize then plugged it into the 30 amp inverter feed outlet, it took a minute or so for my inverter to qualify the power quality (volts & Hz) then it started loading the generator to support the load.
    I increased the load to 2kw then 3 then 4.5kw and as programmed it assisted the generator to avoid overloading it.
    My next test was to do a 50% DOD on my batteries (Four L16RE-B) then I connected my generator again, this time it attempted to load the generator but the deep discharge on the batteries put the charger into bulk mode and the inverter being set at 3.3kw dropped the generator out because of the load so I stopped the test and put it back on the grid. The AC wattage drawn from the grid was 4.7kw much more than my generator can support.
    At the maximum charge rate of 150a & 29v (4.4kw) is needed.
    What I learned was;
    1) Gen assist works perfectly when assisting the generator with loads that exceed its capacity and it will allow the generator to charge the batteries and pass thru to the house if the batteries are not discharged too deep.
    2) When the batteries are deeply discharged I must have a generator of at least 5kw in order to charge the battery bank. The inverter cannot lower the charge rate to keep the AC input at the 3.3kw.

    We have different systems but I thought I'd share my experience.
    This is all new to me and quite a learning experience.
    90cummins
  • BB.BB. Super Moderators, Administrators Posts: 31,688 admin
    Re: Generator procedure?

    These new inverters with generator support--It does almost sound like magic (very expensive and complex magic :cry:).

    Are you sure that you cannot limit charging current below 3.3 kWatts? I would think there are two ways of doing it. One is programming the DC output charging current maximum value. The second would be to program the AC input circuit breaker limit. Either should limit charging current, and the breaker limit would be useful for those with a smaller genset/AC branch circuit.

    Just guessing here--I do not have one of these guys, and I have not cracked open the manual either.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • stmarstmar Solar Expert Posts: 362 ✭✭✭
    Re: Generator procedure?

    You might want to check and make sure you can't adjust the charge rate, mine is an older model and you can set the Max Charge rate in the Menu. It would seem that would be a normal function for the inverter since during certain situations you will have deeply discharged batteries. Keep us posted on your progress so that we can all learn some more.
  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: Generator procedure?

    I'll have to read the manuals again, there's a lot in there so possibly I missed it.
    When I set parameters it wanted to know the ah/rating of the batteries and type (flooded) so the charge rate may be set according to the battery rating's.
    90cummins
  • BB.BB. Super Moderators, Administrators Posts: 31,688 admin
    Re: Generator procedure?

    Yea--That is the down side when the software engineer decides to be "helpful" and make a bunch "configuration choices" based on your entering the battery bank AH capacity. But it is not obvious what choices have been programmed/set to a default/or are editable.

    And sometimes, the AH setting is just so the display can show XX% capacity/state of charge/based on AH consumed/recharged by the inverter-charger.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Generator procedure?

    The only thing the Amp hr capacity set's that I know of is the 2% ending amps of the charger. If you chose " Flooded " then you got the prepackaged charging voltage algorithm. From the Basic screen you can change the ACbreakers size and the Charge Rate Percentage . No clue what kind of generator you have, if it can't compensate for the load, it will be dropped. The charger is capable of a 90 amp dc @ 24v, so thats 13 - 14 amps AC.

    It's all in the owners manual.


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  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Re: Generator procedure?

    You can set the "Gen support Amps" to a value that is equal to a value either at or below the Continous rating of your generator. The XW will only draw that from the generator when supplying load or charging or combination. Can be adjusted in 1 amp steps. Can start low and work up to what you generator will supply without going out of tolerance. AC 2 has wider frequency and voltage ranges than AC1.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • mike95490mike95490 Solar Expert Posts: 9,276 ✭✭✭✭✭
    Re: Generator procedure?

    There are 3 interwoven settings. I do not have enough loads to exceed the 2700w I have reserved for my 3Kw 6hp 1930's diesel genset. But I do observe daily, loads like the toaster, water pump and blowdryer, diverting amps from the charger, to support the loads.

    AC2 breaker size 19.5A (the ComBox allows decimal point settings the SCP does not)
    Max Charge Rate (% of bank size) 31A
    Generator Support Amps 31.1A
    Generator Support Plus [Enabled]

    i don't think that battery bank size affects the charging current, other than the % of C used in setting max charge.
    other combox settings. I set mine to 1,000A (battery bank size) so the Max charge rate scales nicely as I ramp up load on the cold genset.
    Maximum Bulk Charge Current 50a
    Maximum Absorption Charge Current 40a

    Internally, the XW uses 80% of some of these, and ends up "saving" too much power and not doing what you thought it would do. And sometimes it uses the sum amps of the 2 AC legs, and sometimes not. Grrrrrrr.
    I have AC breakers on my genset to protect it, and don't rely on the XW settings.


    i generally only charge into Absorb for about 1/2 hr, till the amps start to drop some, and then shut down, rather than run the diesel under light load.
    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

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: Generator procedure?

    Did some reading on my Xantrex 4024 and in the Default settings section you can adjust the Max charge rate from 5%~100%. It is currently set at 100%
    Next time I perform a deep discharge test I will set the rate to 50% and see if that keeps the load below 3.3kw.

    90cummins
  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Re: Generator procedure?

    As Mike said you can also adjust the AC2 breaker size setting to limit draw from the generator to @16 amp, XW will regulat load on gen to @80% of that seting or set gen support amp setting to @ 10 amp or less to try to see if gen will support load (charging and/or actual loads). From SCP or Combox can set GenSupport plus and XW will try to balance output loads also.

    having trouble attaching screen shots from desktop PC. Not getting tool bar to show?

    i have AC2 Breaker size set to 30 amp for generator 4600W Continous, 5500W surge
    Have GenSupport set to 18 amps
    Don't have Gen Support plus enabled as gen is at size not recommended.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • 90cummins90cummins Solar Expert Posts: 57 ✭✭
    Re: Generator procedure?
    stmar wrote: »
    You might want to check and make sure you can't adjust the charge rate, mine is an older model and you can set the Max Charge rate in the Menu. It would seem that would be a normal function for the inverter since during certain situations you will have deeply discharged batteries. Keep us posted on your progress so that we can all learn some more.

    Yesterday I went off line to exercise my batteries and perform some additional testing to see if changing the charge rate would prevent the inverter from overloading my generator.
    I set the charge rate to 50% after the batteries were discharged then started the generator. The inverter limited the load on the generator to 3kw so you were correct in stating that lowering the charge rate will limit generator loading.
    Thanks 90cummins
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