inverter&generator problems

atm · November 2021

The problem is this. When my gen comes on line it charges the batteries, but when the inverter reaches bulk it trips on the generator. I reset breaker 5 or more times and it stays after monitor gets to 28.5 volts. I have had 4 different gen on the system in two months and they all do the same thing . Has my inverter gone bad?

mike95490 · November 2021

The inverter manual should describe how it should behave and how things should be programmed to be reliable and not trip offline.

Where is this breaker ? internal to the inverter/charger? on the generator ? a box of random breakers between the generator and inverter ? AC breaker on the 120VAC line or DC breaker on the battery ??

RCinFLA · November 2021

First verify your terms. 'When it reaches bulk' sounds like you mean reaches absorb voltage. Bulk is constant current when battery charging first starts for a battery in partial discharged state. It continues at constant current until absorb voltage is reached where it holds that voltage for some time.

If you mean reaches absorb voltage, this is where load on generator will gradually become reduced.

Generators rpm govenor control must be very stable in frequency output for hybrid inverter to remain locked to generator. Sometimes a generator governor may become unstable when the load changed on it. Sometimes govenor is unstable unless generator has a moderate load on it so when load lightens up it becomes more unstable.

It is possible that the generator voltage rises too much when load is lightened, causing it to become too high for inverter.

RPM wobble is most common problem. Voltage out of spec for inverter is less common a problem. Traditional generators with mechanical governors are often problematic and if rpm in too high, beside possibly approaching high freq spec limit, their AC voltage output is higher the greater the rpm setting.

Check AC voltage and frequency output of generator with no load and moderately loaded with a DVM to see how much it changes with load.

RPM fluxuation is more critical to hybrid inverter and may not be detectable with DVM freq reading. Better to listen to sound of generator. Should be smooth and constant sound, without any 'wah-wah' variance indicating unstable govenor.

Also check the setting on hybrid inverter for maximum AC input current allowed to be drawn from generator. Make sure it will not exceed the capability of generator.

atm · November 2021

Thanks for all the input and solutions at least I know where to start .

BB. · November 2021

if you can link to your brand/model of inverter-charger that will help too.

Many inverter chargers, you can program the size of the branch circuit (home, genset, etc.) for 15/20/etc. Amps. That will limit the current the inverter can pull (during charging, or even when powering loads from AC line).

Generally, circuit breakers for "continuous loads' (in North America), you should use wiring/breakers that are 1.25x the expected maximum continuous current. In the US, breakers/fuses are generally rated to not trip at 80% or less of rated current, and will trip at 100% or more of rated current (may take minutes to hours at 100% current). By using 1.25x (1/0.80), you can avoid false trips during long battery charging cycles.

Since your tripping appears to be much quicker (minutes or 10s of minutes?).... Either your inverter-charging is drawing too much current for your circuit, OR you can have a bad breaker (it does happen--Not often).

If you want to get a piece of test gear--An AC+DC Current Clamp DMM can be a big help. Besides the normal voltmeter stuff, the current clamp just clips around 1 wire and measures the current for your (there are AC only current clamp meters--But they do not work for DC battery systems).

https://www.amazon.com/gp/product/B00O1Q2HOQ (cheap/good enough)
https://www.amazon.com/gp/product/B019CY4FB4 (mid priced--More funcitons)
--And there are clamp meters with "surge current" measurement functions

-Bill

inverter&generator problems

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