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Axpert 3KVA - Solar vs Grid to power load


douwgza
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Hi all,

 

Lets say I am using the 3KVA Axpert with PV and Batteries sized right for my application.

 

As I see it program 1 setting would be SOL/SBU and inverter will then automatically change between LINE and BATTERY MODE depending on the voltage setting you set in programs 12 and 13.  

 

In program 1 you can select SOL, UTI or SBU.  SOL would seem to be the right option but would there be a reason to choose SBU?  SBU would seem to mean that even if the panels can supply the load, if the battery levels are low it must use the grid and PV to charge the batteries and grid to supply the load.  SOL seems to mean that if the panels can supply the load, continue supplying the load even though the battery levels are low - does the PV charge the batteries as well in this mode if there is sufficient power?  Is it basically a priority of charging (SBU) over supplying the load (SOL)?

 

Can the PV supply the load AND charge the battery when program 1 is set to SOL?

 

So, if your load is low during the day you will see the benefit of using the excess stored energy at night.  For the guys that have this unit installed with PV - how has this been working out for you?

 

Can someone clarify this please - have I got it right?

 

Cheers

Douw 

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  • 4 weeks later...

Hi, I have the same unit and I've tried all three modes, (Under option 1)  none have been ideal thus far. I have discovered my batteries (calcium lead acid) were undercharging, and reverting to Grid priority for a few days sorted this out.  

 

I still seem to be losing (leaking) a lot of power overnight when there is no, or very little load (in the dead of night).   According to Efergy I'm losing about 400w but this when compared with the pre pay meter log it looks more like 250w  I believe Power Factor can make the Efergy inaccurate at low loads. Still very high.  I also wonder is this inveerter actually feeds back to the grid inadvertently.  I believe some pre pay meters (W Cape) can actually measure backwards (but not as a credit).  Does anyone have any info on this ?

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I also wonder is this inveerter actually feeds back to the grid inadvertently.  I believe some pre pay meters (W Cape) can actually measure backwards (but not as a credit).  Does anyone have any info on this ?

 

The Axpert inverters cannot feed back to the grid. Yes, some prepaid meters can measure flow in both directions.

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Thanks SuperDIY 

Any ideas on how to reduce overnight drain.  I only have a few LED security lights and a AAA fridge, I estimate no more than 100 -150w  I seem to be loosing about 40% of my battery charge over night (800Ah). I basically lose all the gain I get during the day.  Maybe someone has come up with the 'ideal'  settings for this inverter in SA.

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Thanks SuperDIY 

Any ideas on how to reduce overnight drain.  I only have a few LED security lights and a AAA fridge, I estimate no more than 100 -150w  I seem to be loosing about 40% of my battery charge over night (800Ah). I basically lose all the gain I get during the day.  Maybe someone has come up with the 'ideal'  settings for this inverter in SA.

 

Regarding the access usage of the inverter I cannot really comment.

 

Claims were made that the infini also uses a lot (250W) on idle. I've bought a din rail meter with digital V, A, W, VA and pf readouts. Plan is to install it next to the changeover switch in a surface mount DB, but in-between the infini and the mains connection in order to do some measurements regarding power consumption by the infini as well. I'll post the results once I have them.

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Thanks SuperDIY 

Any ideas on how to reduce overnight drain.  I only have a few LED security lights and a AAA fridge, I estimate no more than 100 -150w  I seem to be loosing about 40% of my battery charge over night (800Ah). I basically lose all the gain I get during the day.  Maybe someone has come up with the 'ideal'  settings for this inverter in SA.

 

Maybe this could assist to find your power losses.

 

I replaced my kitchen fluorescent tubes (4 of them) with LED's tubes. Took the easy way and bypassed the circular thingy that must be there with the device they provided to do it. Saves you on rewiring apparently. For months I lost 200w when the lights in the house are on.

 

Turns out the fluorescent tube fittings had 4 x 50w inverters in them, which I never knew of. So, I had to do the rewiring. :-) 

 

How did I find it?

Came up when I switched the light circuits on!!!

 

On the DB board, I switched all the circuits off, leaving the mains on. Checked the Efergy that the drain is zero.

Then I switched the circuits back on, each time checking the Efergy reading.

In the process, I found a bunch of viper loads, for as a circuit comes on and it starts drawing a bunch of watts, I traced the plugs that circuit feeds. 

 

Was a very enlightening exercise. 

 

Today, I am left with +-60w 'viper' loads which I suspect are the micowave and freezer on standby, the garage motors etc. But I can live with that ... for now, for 60w x 24h x 30days = +-R80.00 per month .. not too expensive to keep SWAMBO happy-ish.

 

Ps. Word of advice. Test goes much smoother with SWAMBO and little ones not present. The on/off will cause YOU a lot of stress, when they get gatvol. :-) 

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Thanks everyone, it's a big learning curve going solar, but fun and I've learnt a lot.  

I would love to hear how others have fine tuned the expert inverter settings, to work & fit their lifestyles (and wallet) .

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