Axpert invertors

gimpex said:
Yes all lights are under 1300w including outside lights , but of course you wouldn't have them all on at the same time.
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I think you need to invest in LED :) All the lights in my house together are less than 400W - if I switch the garage lights off, it goes down to 250W.
 
How does the input power switch between Ac input and solar array input? For example if 100% power needed and solar can provide only 50% , does grid provide 50% extra or bypass and provide 100% for the Axpert MKS plus models?
 
Haggers12 said:
How does the input power switch between Ac input and solar array input? For example if 100% power needed and solar can provide only 50% , does grid provide 50% extra or bypass and provide 100% for the Axpert MKS plus models?
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Nope... If the solar can provide full load, then that is fine. Otherwise, it can use the battery too (as an option). If you use grid power at all, then you can't use the solar - it is a switch.

The reason is that the inverter does not sync to the grid, so you can't run the grid together with the inverter. The InfiniSolar can do that - 3kW version is about R15 or R16k.
 
greg_SA said:
Nope... If the solar can provide full load, then that is fine. Otherwise, it can use the battery too (as an option). If you use grid power at all, then you can't use the solar - it is a switch.

The reason is that the inverter does not sync to the grid, so you can't run the grid together with the inverter. The InfiniSolar can do that - 3kW version is about R15 or R16k.
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Thanks Greg - so other than the ability to feedback, that is the main reason for the price diff between this and the Axpert. I will then go for the infinisolar as it means I can build my solar array over time.

Regards
Haggers
 
Haggers12 said:
Thanks Greg - so other than the ability to feedback, that is the main reason for the price diff between this and the Axpert. I will then go for the infinisolar as it means I can build my solar array over time.

Regards
Haggers
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For sure - if you plan to install solar PV panels, then the Infinisolar is the right way to go... Only issue is that it is not technically approved for connection to the grid in South Africa. You can set it up via software so that it doesn't feed back into the grid, but I still think it is technically illegal. Might have issues with COC, or if you want to sue it as a grid-tie inverter.

Another option might be a Victron inverter.
 
Vitamin_Sea said:
@ Amith, you can start with 3 , or six panels even. when further upgrading, you might be able to get away with 12 x 300Wp panels, as the NOCT values will fall safely in the acceptable range.

I took some photos wednesday two weeks ago, it really is dead simple to install. it is similar to pluggin in a UPS, except there aint no plugs. I have no formal qualification and it is really easy, it just want to neaten it up before getting a COC done, for a case of beer.

essentially this is how it goes:
Utility power to DB box in house through Earth leakage --> 16mm cable to POWER IN on Axpert --> 16mm from the axpert POWER out to the busbars. the batteries all linked up in series with 16mm cable, and stacked next to the deepfreeze to keep them cool (at 9'C) as it is proven to extend the life tremendously.

with a few posts im new here, but there is some nice youtubes from user justin case, his unit is the taiwan model by mpppower. send me a PM with your email and I will send you the photos, as i struggle to get them into this post.
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Why 16mm cables? Surely 10mm should be sufficient for 4200W over 230V?
 
SoftDux-Rudi said:
Why 16mm cables? Surely 10mm should be sufficient for 4200W over 230V?
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Please don't even bother to listen to him... No protection, no earthing, no breakers / isolators? Sure, you go right ahead and buy your COC with a crate of beer... :whistle: If you don't know what you're doing, please don't follow incorrect advise...

At a -bare minimum-
- Appropriate sized cable (and no, 16mm won't even go into the inverter's terminals)
- Appropriate sized breaker on the inputs AND outputs of the inverter
- If the Inverter is far away from the DB, appropriate breakers/isolators in the DB as well, on inputs AND outputs
- Indicator lamp (as required by SANS) to VISUALLY INDICATE, alternative power is present
- Appropriate labeling of the DB board (i.t.o. alternative power)
- Appropriate fuses on batteries, with appropriate DC Disconnects
- Appropriate cabling for batteries
- Appropriate fuses on solar panels, with DC Disconnects
- Solar panels must be earthed (correctly)

There's quite a few things to look at, and do correctly. The above is not even a complete list...
 
Hi Chris,

This looks like a good list to start with. Would it make sense to flesh it out a bit or even start a thread for something like that? Being a technical guy and it looks like there are others here, so it might help others too, I would like to know what is required and what is good practice around the DB and around the inverter and solar panels.

I do understand current, wire thickness and length and the voltage drop going with it, but where are isolators, circuit breakers and surge protectors required or just good practice? Some stuff I would not mind tackling myself, but even for the rest that I will need to get an electrician for, it does help to know what is needed. It also helps with the planning phase. For instance my DB is in the passage between the rooms, but is pretty small. So I need to figure out if all the stuff that needs to go in there will fit or if I need to start to think of another place to have a second DB.

John
 
There are SANS documents the outline the requirements. You have to buy the documents. Most electricians have them.
 
Of which I guess SANS 10142-1 'The wiring of premises Part 1: Low-voltage installations' and NRS 097-2-1 'GRID INTERCONNECTION OF EMBEDDED GENERATION, Part 2: Small-scale embedded generation, Section 1: Utility interface' are the most pertinent. I have that.

Except if I was really asleep, it does not touch the solar and battery sides. Searching on the web a bit, I found, with photos, the Microcare 1 string combiner box. So it looks like they use an isolator, surge suppressor and a fuse. The photo is a bit fuzzy, but the isolator looks like an AC one and only rated to 420V, so too low if one have 11-12 300W panels in series, or is that what people use?

The surge suppressor I can understand, but why the fuse? It is not as if a solar panel can give a lot more current than its optimal working current even if you short it. Or does the fuse work in conjunction with the surge suppressor?

And what about the batteries? I guess a fuse as close to the batteries as possible is useful. Should one have an isolator?

With a surge suppressor on the solar panel side, should one also have on the 2 AC sides?

Hmmm, maybe this should go in another thread?
 
JohnHay said:
Of which I guess SANS 10142-1 'The wiring of premises Part 1: Low-voltage installations' and NRS 097-2-1 'GRID INTERCONNECTION OF EMBEDDED GENERATION, Part 2: Small-scale embedded generation, Section 1: Utility interface' are the most pertinent. I have that.

Except if I was really asleep, it does not touch the solar and battery sides. Searching on the web a bit, I found, with photos, the Microcare 1 string combiner box. So it looks like they use an isolator, surge suppressor and a fuse. The photo is a bit fuzzy, but the isolator looks like an AC one and only rated to 420V, so too low if one have 11-12 300W panels in series, or is that what people use?

The surge suppressor I can understand, but why the fuse? It is not as if a solar panel can give a lot more current than its optimal working current even if you short it. Or does the fuse work in conjunction with the surge suppressor?

And what about the batteries? I guess a fuse as close to the batteries as possible is useful. Should one have an isolator?

With a surge suppressor on the solar panel side, should one also have on the 2 AC sides?

Hmmm, maybe this should go in another thread?
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A fuse on the battery and solar panels is very necessary, and an isolator helps with the connection / disconnection. DC voltages are "less forgiving" than AC, so it helps to have some extra protection in case something goes wrong, somewhere.
Surge arrestors on the panels help with lightning.
 
I'm all for protection and safety that make sense, but not for just spending money on stuff that do not increase safety. That is why I'm asking. On the battery I do understand the need of a fuse. Batteries can do lots of amps if shorted.

On the solar panels I do not understand the use of a fuse yet. I can short a single string and will only see +- 9A (Isc). But that is also pretty close to their working current (Imp). You will struggle to find a fuse that allow Imp but blow before or at Isc. So if there is a use for a fuse, it must be something else.
 
JohnHay said:
I'm all for protection and safety that make sense, but not for just spending money on stuff that do not increase safety. That is why I'm asking. On the battery I do understand the need of a fuse. Batteries can do lots of amps if shorted.

On the solar panels I do not understand the use of a fuse yet. I can short a single string and will only see +- 9A (Isc). But that is also pretty close to their working current (Imp). You will struggle to find a fuse that allow Imp but blow before or at Isc. So if there is a use for a fuse, it must be something else.
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Sigh... If you want to die, go right ahead and go and create shorts. PV Strings can be upwards of 100V to over 600V DC volts (fatal)... Same with the current, depending on how the panels are configured (to match the requirements of the inverter)... Go and electrocute yourself with that, and then come back and tell us about it. Oh wait, you'll be dead...

Even a short, will create such an explosion that you more than likely won't even survive. Then there's also the fact that IF you survive, your equipment will more than likely be damaged beyond repair...

But hey - what do we know right.
 
"- Solar panels must be earthed (correctly)"

Chris could you perhaps indicate how this should be done the correct way!!!!!
 
savage said:
Sigh... If you want to die, go right ahead and go and create shorts. PV Strings can be upwards of 100V to over 600V DC volts (fatal)... Same with the current, depending on how the panels are configured (to match the requirements of the inverter)... Go and electrocute yourself with that, and then come back and tell us about it. Oh wait, you'll be dead...

Even a short, will create such an explosion that you more than likely won't even survive. Then there's also the fact that IF you survive, your equipment will more than likely be damaged beyond repair...

But hey - what do we know right.
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Hi Chris, I did not mean to ruffle the feathers.

I'm try to find out and understand how things should be done and why. If there is a site where I can read about it, especially the why, just point me there. While my solar experience is a little low, I do understand electronics. I have even built an electric car. At 170V its voltage is a little lower than what my solar string will end up with, but I'm sure the current will make up for it. :-)

Back to solar. Take for instance the Renesola 300W panel. Its short circuit current (Isc) is listed as 8.69A. I have tested by shorting that through my Fluke multimeter and I see a little less, but then it is winter. Point is I do not think a panel can give more. So if I connect say 10 of them in series, I'll have an open circuit voltage of about 450V, but still only capable of a little less than 9A. Yes it will create a big bang if you short it and it can be lethal if you are in the middle of it, but will the fuse blow? I do not know, but doubt it because a panel can only give a limitted current (Isc). It is not like a battery that have an almost limitless current capability.
 
Here are some articles that seem to say that for arrays with less than 3 strings, fuses are not needed. It looks like the fuses are needed when you have 3 or more strings because then if something go wrong in a string, the others can over-current it. That makes sense. So with an Axpert, you will probably have a lot of strings, so that needs to be fused. On an Infinisolar with its much higher MPPT voltage, you will probably only have one or two strings and fuses will not help.

http://https://www.swe-check.com.au/pdfs/library6.pdf
http://https://www.windynation.com/jzv/inf/how-properly-fuse-solar-pv-system
http://http://www1.cooperbussmann.com/pdf/9df1f7ec-8c62-4210-8cf8-9504927394f0.pdf
 
JohnHay said:
Here are some articles that seem to say that for arrays with less than 3 strings, fuses are not needed. It looks like the fuses are needed when you have 3 or more strings because then if something go wrong in a string, the others can over-current it. That makes sense. So with an Axpert, you will probably have a lot of strings, so that needs to be fused. On an Infinisolar with its much higher MPPT voltage, you will probably only have one or two strings and fuses will not help.

http://https://www.swe-check.com.au/pdfs/library6.pdf
http://https://www.windynation.com/jzv/inf/how-properly-fuse-solar-pv-system
http://http://www1.cooperbussmann.com/pdf/9df1f7ec-8c62-4210-8cf8-9504927394f0.pdf
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Ok...
 
JohnHay said:
I'm all for protection and safety that make sense, but not for just spending money on stuff that do not increase safety. That is why I'm asking. On the battery I do understand the need of a fuse. Batteries can do lots of amps if shorted.

On the solar panels I do not understand the use of a fuse yet. I can short a single string and will only see +- 9A (Isc). But that is also pretty close to their working current (Imp). You will struggle to find a fuse that allow Imp but blow before or at Isc. So if there is a use for a fuse, it must be something else.
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Well, then you obviously don't need fuses, simple as that ;)
 
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