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Slightly unique solution required - input appreciated


Hannes7212

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1 hour ago, cvzyl said:

one forum member

To be fair, the biggest rain storm in a decade invaded his trunking and took the inverter out. Buuut, it is true that they don't have the same IP rating as other units. I think they are IP20. The Victron units are only slightly better at IP21, though given that the blue units survive on yachts and barges, there is more to it than just a number :-)

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25 minutes ago, The Terrible Triplett said:

And the bank is bigger than 600ah ... just saying. 

TTT, it is 60A charging rate per inverter. To deliver the 12-13 kW will require 3 Infini 5kW's which would mean max 180A charge rate and 1800Ah bank. Plus a truckload panels.

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24 minutes ago, cvzyl said:

Plus a truckload panels.

Ain't that the truth.

Personally I would simplify it as far as one can for it is a huge system. Less parts are always better. But that is just me.

24 minutes ago, cvzyl said:

3 Infini 5kW's which would mean max 180A charge rate and 1800Ah bank

That is something I cannot seem to "get".

For just because it was there, I had two controllers connected to the same bank. Settings where identical, but one always backed off.

And if they where interconnected, operating as "one" unit, I don't get how when they all can produce max 60amps each, that one can make it 180?

Combined they will produce max 60amps, yes for a longer time because of all the panels split between them all.

I am being stupid here?

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27 minutes ago, The Terrible Triplett said:

Ain't that the truth.

Personally I would simplify it as far as one can for it is a huge system. Less parts are always better. But that is just me.

That is something I cannot seem to "get".

For just because it was there, I had two controllers connected to the same bank. Settings where identical, but one always backed off.

And if they where interconnected, operating as "one" unit, I don't get how when they all can produce max 60amps each, that one can make it 180?

Combined they will produce max 60amps, yes for a longer time because of all the panels split between them all.

I am being stupid here?

TTT

I've never parallelled these so I speak under correction but as far as I know the 3 inverters can share a battery bank. That means that if each of them has PV panels connected (let's say 7.5kW each) then each inverter will output 60A charging to the bank. That adds up to 180A doesn't it? I know the guys use the Axperts this way, I've heard that some guys are also running the Infini's (5kW) in parallel.

C

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6 minutes ago, cvzyl said:

... each inverter will output 60A charging to the bank. That adds up to 180A doesn't it?

I have heard that before here on the forum and elsewhere, but never asked.

Today I wondered, if it is 180amps, then the cables must be big enough for 180amps, and the fuses. That will mean that 180amps are going back up the wires to the inverters circuitry. And they are each max 60amps.

So I wondered, What will the total amps from the 3 x inverters in parallel, measured at the batteries, total to? 

I want to bet it is going to be max 60amps?

 

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1 hour ago, cvzyl said:

1800Ah bank.

Another thought.

If I buy a 1800ah bank, the controllers I want for my massive investment in batteries, better be able to make me coffee, for their cost would be negligible compared to the cost batteries.

The last thing I want to find out afterwards is say the controller/s cannot be programmed to reach the battery manufacturers highest voltages like say float or equalise.

That the controller cannot be auto programmed to equalise as per manufacturers specs / or manually.

I would want to buy the best configurable controllers money can buy.

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Hi TTT, apparently the Infini 5000 Plus can handle 10000w of pv and max charging rate of 4800w. Using 3 units it would easily handle the battery bank of 1800ah. ( My calcs? ) If the three is connected in parallel and you use three sets of cables you would push 3 x 60  amps into the batteries ( If the max charge is 60a as per your example) you will get 180a. Attached the spec sheet link

http://www.thepowerstore.co.za/userfiles/file/Brochures/InfiniSolar_DS_1.pdf

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21 hours ago, Chris Rossouw said:

Hi Chris, is the Imeon 9.12 not going to fullfill what Hannes wants? This is exactly the way I setup my system. Just not sure whether he's got 3-phase or single?

Hi Chris

The Imeon  is only going to handle the load in its "power assist" mode and having a 3 phase gennie I find 3 phase the pits. I would not recommend a 3 phase inverter unless the application required it.

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8 hours ago, Chris Rossouw said:

Hi TTT, apparently the Infini 5000 Plus can handle 10000w of pv and max charging rate of 4800w. Using 3 units it would easily handle the battery bank of 1800ah. ( My calcs? ) If the three is connected in parallel and you use three sets of cables you would push 3 x 60  amps into the batteries ( If the max charge is 60a as per your example) you will get 180a. Attached the spec sheet link

http://www.thepowerstore.co.za/userfiles/file/Brochures/InfiniSolar_DS_1.pdf

Chris

That is also the way I understand it.

Hannes, you can decide for yourself what equipment suits your needs and whether you want to exclude inferior manufacturers. I simply mentioned that with the Infini this type of operation is normal, no special configuration etc. I am sure it is possible with lots of other types of equipment, might be a bit (or a lot) more complex but finally you must install something you have confidence in. If you feel that only premium manufacturers would give you that confidence then SMA, ABB, Victron is where you should look.

C

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2 hours ago, Chris Hobson said:

Hi Chris

The Imeon  is only going to handle the load in its "power assist" mode and having a 3 phase gennie I find 3 phase the pits. I would not recommend a 3 phase inverter unless the application required it.

Chris, problem is most of the businesses have 3-phase power. I suppose you could use 3 single phase inverters, each on one of the three phases, but I am told that you could get the grid to go out of balance. ( Don't have enough knowledge on the grid distribution ) Secondly even with 2 x Infini 5000 plus inverters, your cost becomes enormous.

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I think we're over-engineering this. Hannes said he needs 15kw constant (well, I suppose for as long as possible, that obviously can't be done at night) and that only 1.5kw really needs the UPS backing. So talking about three hybrid inverters that can handle the whole 15kw potentially from battery seems overkill.

What you need is a 20kwp of PV, 15kva of GTI, and 3kva of backup. The oversized PV array is to get 15kw for a larger part of the day.

I'd get a big Fronius Symo (they make up to 20kva), and a 3kva multiplus. Much smaller battery required then.

72k for the big GTI. 26k for the Multiplus. Say about 100k round.

Now admittedly some of this depends on whether it's 3-phase or single-phase. I see the Infini only goes up to 5kva in single phase, and they are around 50k a pop.

So unless I am missing something and there is a reason you need more off-grid capacity, I think the most cost effective setup will be GTI-heavy.

If you're still convinced that you need a Voltronic in there, use an Axpert for the backup part :-)

Edit: I made the same 3-phase vs single-phase mistake. The symo is 3-phase, For single phase you'll need 3 5kva Primos. That'll be a a bit more expensive, but it should still beat 3 large voltronic hybrids.

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Assuming single-phase again, you can also tie a 10kva Quatro with one or two 5kva Fronius units on the output (one-to-one rule, the GTI can't be bigger than the Multi), then you have 10kw backup and potentially your full load while the sun is shining. 65k for the big Quatro, 28k for the Fronius Primo. Still beats the pants off 3 large hybrids.

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Agreed plonkster, I missed the part where only 1.5kW is required on battery backup. Then obviously it makes a lot more sense to use GTI's. I also like the Fronius stuff.

BTW, it seems like Sustainable is running a special on most of their Victron equipment.

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24 minutes ago, cvzyl said:

BTW, it seems like Sustainable is running a special on most of their Victron equipment.

Given that they are usually 15%-20% above everyone else, how much of a special is this really? I'll check it out though :)

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14 hours ago, Chris Rossouw said:

... you will get 180a ...

Sorry guys, help, I am still not sure how.

Because it is parallel connection? 

Will one see 180amps going into the bank at times via the BMV in other words?

 

5 hours ago, plonkster said:

I think we're over-engineering this.

Yes, I agree. Less parts the better.

However I would be rather peeved if I have a 20kw array grid tied and Eskom goes off and I must wait for it to come back to use the array. Ideal would be to always use the array with a small battery bank for low sunlight cases. Like my system. :P

 

Just saw these UPS'es come in. Online ones are inherently inefficient, seems not anymore: " Under poor power conditions, the UPS will run in [On]Line Mode, which guarantees the highest level of protection and the best possible power quality. When the input power quality is acceptable, the UPS switches to ECO Mode, which increases the total output power efficiency by up to 96%. "

https://www.cyberpower.com/ph/en/product/sku/OLS3000EC

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On my phone so sorry for crypticness...

On closer inspection I need 3kW (ish) backup on phase of which 1.5kW is the servers and 1.1kW is the server aircon so a 5kW Infini can work and if I am paranoid add a 3kW online UPS with 15min battery backup only for the servers.  Then 7kW for the other phase for the call centre agents and monitoring screens so maybe 2 x 5kW Infinis in parallel.

Fo all above combined 4 hrs backup is required so therefore the big battery bank. 15kW or so of solar to offset running costs for now with the ootion to extend. Cool.

Only nagging question now is if reliability of Infini good enough for this application...

Thank you very much for all the input. I hooe I can return the favour soon!

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24 minutes ago, Hannes7212 said:

... paranoid add a 3kW online UPS with 15min battery backup only for the servers.

If it was me, I would be paranoid yes. I have a online UPS protecting my servers. Saved my bacon twice already.

25 minutes ago, Hannes7212 said:

Only nagging question now is if reliability of Infini good enough for this application...

Depending on the client, let them make the call if they understand the pro's and cons for a cheaper inverter.

If not, or they say no, then that answers your concern, which is very valid.

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9 hours ago, plonkster said:

Assuming single-phase again, you can also tie a 10kva Quatro with one or two 5kva Fronius units on the output (one-to-one rule, the GTI can't be bigger than the Multi), then you have 10kw backup and potentially your full load while the sun is shining. 65k for the big Quatro, 28k for the Fronius Primo. Still beats the pants off 3 large hybrids.

Single phase on 15KW? That's risky...? I would have used the Infinisolar as well, know it can do what the OP expects. 

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19 hours ago, The Terrible Triplett said:

Sorry guys, help, I am still not sure how.

Because it is parallel connection? 

Will one see 180amps going into the bank at times via the BMV in other words?

 

Yes, I agree. Less parts the better.

However I would be rather peeved if I have a 20kw array grid tied and Eskom goes off and I must wait for it to come back to use the array. Ideal would be to always use the array with a small battery bank for low sunlight cases. Like my system. :P

 

Just saw these UPS'es come in. Online ones are inherently inefficient, seems not anymore: " Under poor power conditions, the UPS will run in [On]Line Mode, which guarantees the highest level of protection and the best possible power quality. When the input power quality is acceptable, the UPS switches to ECO Mode, which increases the total output power efficiency by up to 96%. "

https://www.cyberpower.com/ph/en/product/sku/OLS3000EC

Interesting thing about most of the online ups systems is that they have mickey mouse charges built in so once you have depleted the bank and need to recharge from AC to be ready for the next grid failure you have a problem.  I got a quote here on a 15kVA unit but the re-charge time for he battery bank we need is 28hrs!!  Poor batteries...

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OK all your inputs have been fantastic.  I am writing up my proposal now and have decided to go with the Victron / Fronius combo with a small online UPS for the servers, especially considering the fact that the solar is an optional extra and we were asked to be able to add that later.  Just putting myself in my client's shoes I would want to have the big brand backing on this one.  Personally I have not had one of the many Voltronics in the field fail but I must add I always leave at least 50% headroom when using them so that those fans hardly ever come on.

Anyway, the irony is that the big debate with the client will be about batteries.  R150k plus VAT for lead vs R320k plus VAT for LiFePO4....

Cheers

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On 1/21/2017 at 3:25 PM, The Terrible Triplett said:

However I would be rather peeved if I have a 20kw array grid tied and Eskom goes off and I must wait for it to come back to use the array. Ideal would be to always use the array with a small battery bank for low sunlight cases.

There are always overall limits to consider. I don't know if the other systems have a similar rule -- I expect the rule would apply to all systems as the inverter has to be able to handle the full PV capacity in feedback -- but when tying GTIs to the output of a Multiplus there is a 1:1 rule. You can't have more PV on there than you have backup capacity. That means you must put down a rather large multiplus, and once you do that, you can't very well have too small a battery bank.

I suspect what I'd do is come to some kind of compromise. Tie 3kwp of PV in such a way that it remains available even when the power is down, or something like that. Not perfect, you still have the other 12-17kw offline, but that's the compromise. Of course that complicates matters yet again, having part of the PV feeding in a different manner...

With the equipment Hannes decided on he's got flexibility. For minimal extra outlay you can configure part of the PV to directly feed your battery bank, or if you buy your PV inverters so that the 1:1 rule is in place (even if you don't tie them that way now), nothing prevents you from moving (one of) them to the output of your backup Multiplus and form what Victron called a hub-2 system (although the hub systems are all going away in favour of ESS).

In other words, I wouldn't worry about having 20kwp offline at this point. When power failures become a big problem again, the important thing is that you must be able to reconfigure without too much extra cost. Which you can do with the Victron+Fronius combo, as long as you size them right.

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