The online voltage drop calculators say that you are fine.

If your transmission distance increased more than 6m one way, the answer could change quickly.

Drgreatone:

Thank you boss. Its just 2 415watt panels with 32v and abt 13amp connected in series. Used a 4mm double core wire. Saw that it can take up to 1000v and abt 30amps online, just needed ppl's personal experience/choice.

First you look at how you are arranging your solar panels in series and parallel.

Say you had 4 units of 550w panels in 2S2P, it would call for a different cable gauge than if you had them in 4S over thesame distance.

So you look at the max amps your panel will generate - in the 550w panel case about 13.5a per panel so if you had a 2S2P arrangement you would be sending 26a from solar panel to charge controller - that calls for a 6mm2 cable as minimum gauge to carry that 26a then to have a less than 3% voltage drop you may need to upsize to 10mm2 (depends on distance and you use a voltage drop vs distance chart for this).

If you were setting same panels in 4S for a max amps of 14a but much higher voltage then a 6mm2 cable would be perfectly fine even across a relatively large distance (again the charts will tell you minimum cable gauge to maintain X% voltage drop over X distance).

In this 4S config you could even get away with 4mm2 cable but I would not recommend.

This above is the general science - for your 800w situation how many panels do you have? What are the panel VmP and lmp (current) and how do you plan to arrange the panels? 2 in series then 2 in parallel or 4 in series? We can know your exact cable gauge needed if you answer these questions.

Drgreatone:
I av come again with my curiosity. How do u determine the wire guage from solar panel to charge controller. Gone through different sites and seeing different recommendation. Someone recommended 10mm for use wit 800watts panel that 4mm wud be too small yet google gave a max volt/amps of 1000/36 for a 4mm double core wire. Distance is about 5 to 6m. Thank you for ur kind responses

Not recommended since it just keeps putting out a fixed voltage and cannot throttle current (no charge regulation)

It is something you could use if the process was under constant monitoring and you had a BMS in line to disconnect the charger but these are all very unideal situations.

You want a smart charger where you can tell it what voltage to charge to, it gets there and tapers off to float nicely or just terminates the charge - popular opinion is that Lithium batteries don't need to float.

elpiro:
Good afternoon all, I would like to ask if this external charger is suitable for charging Lithium ion battery of 48volts. Thank you

All power electronics derate for temperature and this has nothing to do with the power factor.

So you may have an Asian origin inverter where the maker fails to publish the temperature derate curves but the fact of physics remains and cannot be escaped.

For a practical example and as a guide to understanding the internals, the 5kva Victron actually has a ~5kw rated transformer in it - the manufacturer expects you to load a max of 4kw at 25 degree C however there is a 30% overload (for up to 30 minutes) ability built in.

This overload capacity is there for trained installers to understand and use (not abuse ) properly and is one of the reasons behind the very positive field reviews and testimonials of the robustness of the Victron units.

As a point of fact, per design, the units will shut down in case of over-temperature in the internals long before an actual electrical overload occurs.

I hope this puts paid to any fears.

zeestone99:


Is that your reason for choosing the victron.
Do you know victron's output derate with respect to temperature. The power factor is not 1.
I will choose the victron also for other reasons.

For most modern inverters, this behaviour is settable in the software (settings)

For older versions the ON/OFF button can be (re)wired to drive whether the inverter otherwise functions for PV and mains passthrough while switched OFF.

If I lay hands on a Growatt manual, I will see if the behaviour can be influenced from the settings.

FEGEITOK:


Disclaimer: I don't use Growatt.

But even if I turn off my inverter, it will power devices if it is connected to AC charging.

Since I am not using the inbuilt solar charge controller, I cannot speak for that one.

One thing I do know is that if AEDC seizes power when the inverter is switched off then every connected device will also power down, but if power is restored, even if the inverter is switched off, the devices will have power restored.

Design, install and after sales service different from BalaBlu

The problem is that a noob enters this space and wants to research online and discount the hard worn experience of savvy installers.

Even installers reach out to each other and to recognised subject matter experts for advise and support.

As you said, a competent installer can help deliver a good design and flawless execution and overcome obstacles that would have cost a starting DIYer a lot more money or stress or expensive mistakes.

In the end everyone has to choose their own path because there is a niche and market for each and every - from the penny pinching, poorly informed entry person to the fairly skilled DIYer who paid the price in initial hard lessons and mistakes to the seasoned and well trained professional who has broad experience and depth with various products - all will be alright last last.

zeestone99:



Find a trusted installer like us to do your procurements.

It comes at a cost but many people are penny wise and pounds foolish.

There are so many advantages of having professional installer like us handle your project from A-Z.
You get free consultations and learn from our vast past experience. There's is always a solution to your problems.

You are likely to avoid stress during repairs. Some installers will even give you stop gaps. There is a guy saying his afripower is bad and doesn't know where to take it to. A credible installer will handle that with afripower.

Sometimes u can run into issues and you will need equipments you don't have e.g I have lent people external chargers to boost failing batteries, some lithium chargers to wake up bms etc they would have been helpless and taking it from one repair shop to another.

And blablabla

Eeeeeeeevvvviiiiiiiiiillllllllllllll

You will not take my money in Jesus name!

Oshomo12:


I can't stop laughing,
Hard way the only way!!

They are supposed to learn from others mistake, but nooo, I must make my mine. Anyway, good luck to them.

Like I always say: "energy can neither be created nor destroyed, but changes from one form to another"

It's either we take ur money or alaba boys take it, u can't escape any.

Rods are okay and use up less space and generally easier to make a solid connection with rods using available clamps e.t.c

Ideally you want minimum 6 foot copper rods and at least 2 of such rods spaced 15-20 feet apart and linked with 16mm sq copper cable.

The goal is to get resistance reading 5 ohms or less and then you can bring the earth service into the house and connect all your major energy generators and processors to it.

If you have solar panels, sink at least 1 more rod and bond it directly and solidly to the existing earth system (the connection should be from rod to rod)

These are minimums based on my experience - more material may be needed depending on your soil resistance, amount of energy being processed e.t.c

FEGEITOK:


Let me ask, for a residential apartment should I earth rods or earth mats?

By the way thanks for the pictures! And the advice!!

GEM is a generic name for Ground Enhancement Material. There are so many types and varieties and offers from various manufacturers.

The ones I have access to, Enrico or Buntex .... cost under 25k for a 25kg bag. Make I nor spoil market for sellers.

The trick to saving on material and achieving superior but low cost earthing is to bore/auger a narrow hole in the ground for each rod and space your rods properly instead of the massive gullies and trenches people like to dig

Please see reference pictures below

mangolpupa:


I asked around and a bag of GEM of 11kg is about 45k. You would need at least 2 bags to get a mixture with correct density for the lowest application volume as per manufacturers recommendations.

If you are getting intermittent overload errors on the inverter when there are apparently no loads on then that is clearly a wiring issue.

Apart from crossed neutrals consider the possibility of some wires on the load side shorting together from time to time - degraded insulation, water ingress into external lights, faulty equipment e.g water pump or other device shorting internally (what local electricians call a 'back feed') are likely causes.

These kinds of problem typically require some inspired troubleshooting to narrow down else it may be a long and bumpy ride.

If you clearly have a wiring issue then using AC Out #2 will not address that.

Trippledots:


Nice, I learnt something today... thanks boss. the building is a commercial one and generally I don't meddle with their internal wires.

Consider what it means to interrupt 50a of DC current - the contacts must be beefy and huge.

You can find 'battery sensing relays' such as XHM6** series on AliExpress.

What you want to do instead is setup Battery > XHM6** > DC Relay/Contactor and then use the main contacts of that DC Relay/Contactor to interrupt the inverter AC Out. So really you are looking for the XHM6** to detect the battery voltage state and the DC Relay/Contactor to (dis)connect the AC supply to the loads.

In practice you need to consider battery voltage hyteresis and recovery points and also what happens if mains becomes available (ideally want to override the battery voltage based cutoff in the presence of mains or Gen)

viperVIP:

Also, I need a Low Voltage Disconnect module with up to 50a rating, can I get locally?

For that second question, I have made the assumption that all issues like phase rotation e.t.c were already sorted since you said things mostly work.

To quickly find a 'common/crossed neutrals' issue I usually employ a test lamp. With mains available, switch off the inverter AC input breaker so that all supply to inverter loads is coming from battery.

With inverter AC input breaker switched off, apply test lamp between inverter AC out live and mains neutral. If the test lamp lights up then you have an inverter load whose neutral is still on the mains DB. Drop wires off the mains neutral bus until you isolate the offending neutral and relocate it to inverter side - there may be more than one neutral wire causing this problem.

Now repeat the test in reverse - disconnect AC input to inverter and apply test lamp between mains live and inverter neutral bus - if the test lamp lights up, there are mains loads whose neutrals are on the inverter side. For this case decide where the loads really should be and handle appropriately.

This test needs an incandescent bulb, a clear schedule for the day and plenty of patience to do in a complex miswiring situation. If you can get the electrician who (mis)wired the building to attend that would be very good too - they usually know all the shortcuts they took and (mis)wiring they did to cause all these problems, just be nice and kind to them during the process and things should typically work out well.

NiyiOmoIyunade:
My Oga TrippleDots! I hail una o

1. I guess the Fronius is on the AC input side of the Victron Multi/Quattro? Please confirm

What PV related assistants are you running on the Multi/Quattro to manage energy flow.

Are you using the default frequency shift thresholds or more aggressive/conservative ones.

2. If the actual loads are within 10kw per phase where you have 15kva inverters you should look to your wiring on the load side - the most frequent cause of the generic 'overload' light flashing is actually faulty wiring.

You are looking for all neutral wires for the inverter loads properly moved to an isolated inverter load bus/DB and all neutral wires for non inverter loads moved to the mains DB. Any crisscross of neutrals between mains and inverter side causes these kinds of issues.

If you are pressed for time or want the easy way out, move the inverter supply to AC out 2 and set a suitable assistant to run ACOut2 off battery and prevent overloads.....

My Oga TrippleDots! I hail una o

1. I guess the Fronius is on the AC input side of the Victron Multi/Quattro? Please confirm

What PV related assistants are you running on the Multi/Quattro to manage energy flow.

Are you using the default frequency shift thresholds or more aggressive/conservative ones.

2. If the actual loads are within 10kw per phase where you have 15kva inverters you should look to your wiring on the load side - the most frequent cause of the generic 'overload' light flashing is actually faulty wiring.

You are looking for all neutral wires for the inverter loads properly moved to an isolated inverter load bus/DB and all neutral wires for non inverter loads moved to the mains DB. Any crisscross of neutrals between mains and inverter side causes these kinds of issues.

If you are pressed for time or want the easy way out, move the inverter supply to AC out 2 and set a suitable assistant to run ACOut2 off battery and prevent overloads.

See sample assistant setup below - the red circled (de)activates AC Out from battery based on battery voltage - you could also use SoC or other parameter

The blue circled abi na rectangled protects the inverter from an overload situation e.g in the case below for my house disconnect AC out 2 if loads higher than 9,500 watts for 60 seconds and reconnect or activate AC out 2 if loads under 9,500watts for 200 seconds.

Two things are important here -
1. The assistant logic is inverse so that START means STOP since the control is OPEN RELAY TO START.....

2. The backoff time for the AC contactor is tres importante - Victron backend dev strongly discourages the relay cycling rapidly ON/OFF several times a minute - it would stick shut and need visit to service center hence I give a mandatory 3 minutes (200 seconds) rest and cool off period if ever the inverter overloads and a 60 seconds of sustained high load before the inverter trips the AC out to allow large transients to pass with no trouble.

Trippledots:
NiyiOmoIyunade boss greetings. I have two Victron observations I will like you to advice on:

1. I notice Fronius shows that it's back feeding into grid on VRM when the PV harvest parameters favour such, even though back feed into grid is turned off in settings. Have you observed such before? Is this normal?

2. I have some 15kva Quattros and even 10kva ( but more of the 15) that fly into overload sometimes when grid is supplied or interrupted. Any ideas what the cause could be? All are 3-phase systems and not running on ESS.

Thanks.

I have been hoping you would highlight these differences between lightning protection for ground mount vs roof mount so everyone could learn and share ideas.

FEGEITOK:
It would seem that lightening protection systems are differently engineered if the panels stay on the roof versus if the panels are on a stand directly connected to the ground.

Just wanted to highlight this point.

CC OjeySky. He is a strong and highly anointed Deye apostle and fanboy!

Technical note - for comms between these inverters and battery people typically emulate the Pylontech protocol on CAN - this is not always desirable esp as Pylons are 15S and setting up comms on this basis may lockout certain other critical battery parameters. It may be more prudent to pass only battery SoC to the inverter to drive LVD and stats but set your own charge voltage parameters custom as you would have done for any other battery.

EdmundDantes:


Hi. I appreciate the knowledge and insight you give on this thread. Can you be of assistance in getting the components and setting them up at a cost? I have a Deye 8kw with a 200ah/48v battery with bluetooth bms. Would love to have the inverter communicate directly with the battery. Thanks.

Lightning can strike in the absence of rain and even during the day too.

One would need a direct line to the gods to predict when lightning could strike and also be present to effect a safe system disconnect in advance.

A working solar system should have at least the minimum protection - at least 2pcs of 6 foot earth rods sunk in the ground 18 feet apart and bonded together and the solar panel frame/rack and charge controller earth point solidly connected to the rods.

At worst the panels/rack frame should connect straight to the rods while there is another cable service from the rods into the house terminated at a busbar or similar arrangement to earth the CCs to.

litaninja:
Erm, curious about this. I believe it'll only work if you go manually to switch this off every time its about to rain?

So how's that going to work exactly?

Do you have a BMS attached to your battery pack? What is the HVD on your BMS?

When the charger gets the battery pack to 14.6v what is the highest voltage on any 1 cell in the pack?

Are your cells 3.2v nominal?

The answers to these questions will help put your statements in proper perspective.

oloet:


The charger doesn't have an adjustable voltage function, I have been using it like that for 4-5 years now though the lifepo4 are cylindrical in nature

For the over clockers who want to unlock that last 2% storage capacity using a high charge voltage, it is more likely that you will cause permanent capacity loss by charging too high than actually gaining extra capacity - ditto for the 100% DoD folks.

Indeed LFP does not need to be charged to 100% and worst case 90% DoD is probably as deep as you want to go too. Bad things (can or tend to) happen more at the very bottom and top of the charge/discharge curve.

NiyiOmoIyunade:
There are many types and designs of LFP charger with various charging algorithms.

The problem I highlighted was keeping cells at high voltages for a very long time e.g several days.

A charger that gets to 14.6v for 4 LFP cells plans to take each cell to 3.65v - the cells need to be very closely capacity and IR matched or the BMS set very lax to allow this to happen in practice without one or more cells hitting HVD early and BMS cutting off charge.

You don't want your cells or a few of them hitting HVD on a regular basis so a charger like this should have adjustable voltage so that you can back off from the HVD point (set lower than 14.6v) for your regular charging.

There are many types and designs of LFP charger with various charging algorithms.

The problem I highlighted was keeping cells at high voltages for a very long time e.g several days.

A charger that gets to 14.6v for 4 LFP cells plans to take each cell to 3.65v - the cells need to be very closely capacity and IR matched or the BMS set very lax to allow this to happen in practice without one or more cells hitting HVD early and BMS cutting off charge.

You don't want your cells or a few of them hitting HVD on a regular basis so a charger like this should have adjustable voltage so that you can back off from the HVD point (set lower than 14.6v) for your regular charging.

oloet:


Please forgive my ignorance, there are lifepo4 chargers with 14.6v like the one attached, are they likely to spoil the battery too

Be wary of high float voltages for LFP.

For solar charging a high float voltage is okay because there are only limited solar hours in a day but if you are blessed with good supply from the utility spending several days on 27.8v will cause the cells to oxidize internally and slowly lose capacity.

Find a good middle and choose a float voltage that keeps the cells under 3.4v per cell long term after they spend an hour or so in absorb.

Namzy:


Change setting 5 to "USE", then setting 26 and 27 to 27.8 and 27.8 respectively

There are at least 2 to 4 Victron devs here.

Sometimes the greatest things come in humble packages.

But to the matter - say your system runs the ESS assistant, the power assist and dynamic current limiter functions of the inverter are disabled/unchecked but ESS has it own way of managing these things.

Throttling the Gen load demand implies sufficient PV production to service loads and therefore no need for the Gen to run. If the system calls for the Gen to assist loads or battery charging and is simultaneously throttling the Gen output, you can see how that is not very productive

What you describe typically happens when the Gen was manually started (outside the ESS and GX autostart parameters) or the Generator start/stop was suboptimally setup or the ESS multiphase regulation was set to 'total of all phases' in a 3 phase system with Generator assist or the Gen is oversized for the application.

More than one of the above can be true per time.

Most customers would struggle with the Gen being started during the day in the face of sufficient PV except you have undersized the PV relative to load demand. There is a scenario where the Gen is needed to support peak loads and if properly done the Gen will be sized to be just able to provide the balance of energy in the system and hence there should be no throttling.

In short, the overriding philosophy in all systems I know is to run the Gen as hard as it can handle and not derate or buck under the burden. If the Gen is oversized as Nigerians like to do, then good money was and is just being thrown away.

If your design goal is to co-run the Gen efficiently e.g a PV Diesel application that is best done by sizing the Gen properly or failing that an external control loop to force the Gen to run in its most efficient power band per time.

If I will leave any nuggets it will be below;
1) In a PV inverter or mixed AC/DC coupled application, ensure Gen is connected to a separate inverter input, designated as Gen on the GX and never manually started (look to the ESS control setpoints and AGS parameters like 'Quiet Hours' to lockout Gen start in the presence of PV)

Trippledots:


ok Chief. I get your explanation, but I don't think I agree totally as well.

Just the same way the inverter can throttle grid usage, I'm sure in the same way it can dynamically reduce its demand on the gen as pv harvest increases and increase its demand on the gen up until the set input limit before going into passthrough mode, all of this being done without a third-party control loop mechanism_ The system sees a three-phase supply whether gen or grid and acts accordingly. So I think anyways.

I wish we have some Victron backend dev here to clarify things better sha.

Most definitely yes.

Consider that lightning is poweful enough to cross from cloud to object on earth passing through thin air (the air becomes an electrical conductor at such energy levels). Ditto the induced surge in your home wiring can easily arc/jump across the tiny air gap when your breaker contacts are open.

Safe electrical isolators give sufficient space clearance and also sometimes use an insulation barrier to ensure the contacts are truly open. An average home use breaker is not a safe electrical isolator.

oloet:

Does this mean that surge can pass through a breaker even if it was switched off before a storm?

Indeed physically isolating a device from the wall socket or disconnecting the energy source should save it from lightning surge induced damage.

Be aware that opening a PV breaker or any other breaker will not help protect against a surge, a decent surge will jump right across the space between the contacts and do its evil work. When a breaker trips upon impact from lightning induced surge, the surge current already passed through well before the breaker could respond.

You either invest in sufficient lightning protection or physically totally disconnect the device e.g remove both PV cables from CC when a storm is impending

gadgetplanetng:


My inverter manual (TV also) says disconnect from the wall in a storm.

I turn off the circuit breaker for the solar and AC charging when there's a storm.

I hear you boss but I am not sure I agree. I say often that because something appears to 'work' does not mean it is/has been done correctly.

The Victron ESS and PV inverter assistant algorithms are designed to prioritise use of solar first then battery (if self consumption is desired) then Grid and lastly Generator.

In the presence of PV the system will throttle Grid usage to the minimum possible based on current system state and settings (Grid Set Point), if the system starts a Generator and Generator power provided on a correctly designated AC input then the system will flog the Generator for the max input current limit.

Consider that Diesel Gens save diesel consumption within specific loading bands, it is incorrect to assume that the inverter algorithm will automatically throttle Generator load demand into the next possible lower consumption band except somebody took the pain to implement an external control loop to this effect (which control loop is not a trivial undertaking). The inverter simply has no knowledge of the Gen capacity or diesel consumption saving band except for the input current limit set for the AC input the Gen is connected to. This setting is targeted to not overload the Gen and does not contemplate running the Gen 'efficiently'

Trippledots:


The settings were actually done properly and all ACin inputs tagged appropriately in venus o, also cables supplying ACin 1 & ACin2 are direct from source no ATS in-between.. The dynamic reduction from the gen as Fronius harvest increased is actually a good feature as it helps to reduce diesel consumption overall. I just needed your explanation as to why that attenuation occurs.

Thanks boss for your inputs.

At the risk of ruffling feathers, the Victron implementation of energy storage systems, bidirectional energy flow and systems control is far superior to Schneider's

Schneider do make fairly robust kit but their understanding of certain elements can appear backward at times e.g

1) An AGS (automatic gen start) powered off the Schneider 'XanBus' network will go offline in case of inverter failure or battery LVD - the inverter provides power to the XanBus network.

So imagine a situation where inverter goes off and Gen cannot be called to start because the device that is responsible to start the Gen is powered from inverter.

Victron world, the GX device is powered off battery and has internal circuitry sufficient to lock closed/opened the Gen start relay even if you disconnect the power source - this ensures that the Gen can start gracefully one-time in case of inverter or even battery failure - pragmatic beauty in there

2) Victron ESS can identify the Generator connection separately from the Mains (PHCN) and open a relay inside the inverter to prevent Gen backfeed. The only action needed is designate which input on the inverter is Mains and which input is Gen (setting made on the GX device)

Schneider you must incorporate an external relay that disconnects the PV when Gen is on as there is no inbox backfeed prevention. This is a feature that a software update should have solved by now if you had capable hardware.

To your specific question, Victron throttling the Generator production in the presence of AC PV from the Fronius is a result of suboptimal settings or non kosher install.

On the GX device you must designate properly whether AC In 1 is Grid or Generator and ditto for AC In 2, you must also supply the inverter with power from Mains and Generator directly to each corresponding AC Input - the system will then start the Gen when needed and load/flog it correctly.

In the setup you described, there was probably a traditional ATS that switches Mains and Gen through a common output - we encounter this all the time in the field and either run out wires directly from the ATS to provide Mains and Gen separately to the inverter or employ a suitable contactor that switches the common ATS supply to Generator or Mains port of the inverter as appropriate.

Trippledots:


You are well learned in this stuff.....about that bolded, how come the fronius- victron, ac coupled system I have seen has gen output throttled down as fronius output increases above the victron ac load+battery charging load? Is this particular with this connext system only?

You used Option 2 - AC Coupled.

Good luck and do let us know how things work out.

Nexuspulse:
Thanks a bunch NiyiOmoIyunade olopan & earthrealm

Actually the DC elements are hidden inside Conext XW+ Conduit Box & Conext + PDP Panel.

In the end, I utilize the attached diagram and the Fronius Primo came to life. This Austrian technology performs wonders.

The project is for a corporate client at Abuja.

Thank you

This looks like a ready install where these questions should have already been answered at the design stage.

TLDR;;; - you very likely want the AC Coupled Option 2 below - by now I believe Schneider must have made firmware updates that make things better and smoother for the system designer/installer

Broadly, you can use the Fronius PV inverter in one of 2 ways

1) Grid-tie;- where you connect the Fronius and Mains into AC In 1 - in this config, the Fronius will only make power from PV where mains is available - without mains, it will shut down and go to sleep. This is the simplest usage scenario optimized for selling excess PV to grid.

The PV energy from the Fronius will first go to supply loads on AC Out and battery charging and all the excess will be exported to grid - big downside there will be no PV energy made when mains is down so not suitable for offgrid - there are a couple of schemes that may work around this but need extra expenditure.

2) AC Coupled;- this scenario is suitable for offgrid use and essentially sets up a micro grid where you connect the Fronius Inverter to the Schneider AC Out. Certain settings need to have been preset or else sparks may fly - see caveats below

a) Appropriate micro grid settings (e.g MG 50) selected on the Fronius

b) Schneider Conext XW+ or Pro must have appropriate frequency shift settings configured

c) A generator connected to AC In 2 must be fitted with a certain Schneider approved contactor/relay that opens the Fronius PV input whenever the generator is running. You do not, I repeat you do not want to feed in excess PV energy into your generator or else something must break. Of course you can jury rig your own contactor to isolate the PV but warranty is lost.

d) Battery charging by reversing energy from the Schneider AC Out is not automatic - care must be taken to configure appropriate [b] time of use [\b] settings for battery charging - you may need a PLC or Raspberry Pi or other logic controller to make this work smoothly for you else a lot of the Fronius PV potential will be wasted.

e) Size of Fronius PV can not over power the Schneider AC Out - Victron use the factor 1:1 rule so a 6kw inverter can only be mated with a max of 6kw PV or Fronius inverter size limited to 6kw PV output/passthrough - Schneider relax this rule somewhat so allow a roughly 1:1.3 size ratio but I would advise to stick to 1:1 as a max for safety and tolerance.

f) The Fronius will only run when it can sense electricity and then it wakes up and syncs its frequency to match - if your system goes off due to low battery, the Fronius cannot automatically wake it up next solar day, you will need to cold boot the system or preferably have a separate PV with a DC coupled charge controller to put some energy in the batteries and eventually wake the system up.

I could not see any DC coupled elements in your picture and this part is critical to a stable system especially if targeted for industrial use or mission critical

For the pundits when I say connect the Fronius to Inverter AC Out or Mains supply, I expect a distribution/bus bar arrangement with appropriate fusing/breaking and isolation for [Mains supply + Fronius Output + Inverter AC In] or [Inverter AC Out + Fronius Output + Inverter Loads] - essentially you must be able to separately isolate each and every of the energy generators, processors and centrally the consumers for a code compliant install.

These are some of the things I remember from playing with these gadgets back in the day - I must say, my experiences sent me firmly into the hands of Victron as they do all these things so much better and elegantly and robustly.

Nexuspulse:
Hi everyone, please my colleagues and I are having difficulties at arriving where the output of Fronius Primo PV Inverter 8.5–1 with a Conext XW + 8548 E should be connected to (Meanwhile, it is connected AC 1. There is a space for AC 2) I have attached picture for your perusal. Thank you.

I read you correctly boss about what type of AC you use(d). You quoted me but neglected to read what I actually wrote and I have now bolded below.

Without going too technical, your inverter AC uses a VFD to achieve energy savings and some pf efficiency by regulating the compressor motor speed - this process involves taking AC from the mains, rectifying to DC and then inverting back to a different AC waveform to drive the compressor motor.

The workings of the VFD (inverter drive) create voltage spikes/transients/back emf and harmonic distortions which your HF inverter is very ill equipped to handle - it is not just a question of the load wattage your Sorotec saw, but all the noise and distortions and faults and transients generated in the power line as the VFD ran. In fact you may have been better off with a standard 1hp AC mated to the Sorotec.

Beyond the technicals above, it is common for el cheapos to have capacity overstated - they may well use the surge capacity as the running capacity of the machine. Also temperature derating when you use the inverter in a non climate controlled room is a thing.

You already took your loss so let me not belabour the point, all these are for other users to be guided - it is best with el cheapo products to load conservatively say a max of 50% including surge i.e your peak load including spikes should stay well within 50% of the advertised running capacity - only go more aggressive if you have verified your particular machine to be built for that duty cycle.

sintolord:
NiyiOmolyunde, I mentioned 1.5hp LG INVERTER compressor AC. There is no surge. I always use the GEN MODE. At this point, I can say, the AC is working like a 1 HP inverter compressor AC. See what I initially typed;

The day the inverter died with a loud bang, LG 1.5hp inverter compressor AC & Thermocool 219 liters (not exactly sure) freezer were the loads on it.

NiyiOmoIyunade:


As you may know the HF inverters do not like inductive loads - they have virtually zero surge handling and what they do have is usually for 1 or 2 cycles - read like much less than half a second - although you may have an inverter AC, the variable speed motor will still present an inductive load. The physics limitations of switch mode power supplies must be respected as in an HF inverter lacking a large iron core/toroidal transformer they perforce cannot handle the surges and transients created as inductive loads go on and off (when your AC compressor picks up or cuts off). The ability of your inverter to handle surges and transients is directly proportional to the amount of iron present in the transformer due to something called the 'flywheel effect' .
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Ah! 1.5hp AC on a 3.5kw 24v HF transformer based inverter is plenty o

As you may know the HF inverters do not like inductive loads - they have virtually zero surge handling and what they do have is usually for 1 or 2 cycles - read like much less than half a second - although you may have an inverter AC, the variable speed motor will still present an inductive load. The physics limitations of switch mode power supplies must be respected as in an HF inverter lacking a large iron core/toroidal transformer they perforce cannot handle the surges and transients created as inductive loads go on and off (when your AC compressor picks up or cuts off). The ability of your inverter to handle surges and transients is directly proportional to the amount of iron present in the transformer due to something called the 'flywheel effect' . LF transformer based inverters rated for large loads have plenty of iron (more than needed for the application) in their transformers and the FETs switch much slower (hence low freq) and are often large sized and designed to run much cooler - all these factors surges/voltage spikes & transients/ back emf/reverse current/flywheel effect running temps etc impact how well your inverter does with surge loads.

In simple English most budget HF inverters are sorely lacking in the internals needed to run those large and problematic loads robustly for a long time.

There is also the issue of large loads on a 24v system - it is amps flow that makes cables and power electronics heat up which is why you may have seen your fan run more than you expected.

2,000w load on your 24v nominal LFP bank is 75a flowing through the inverter DC bus - even in a premium system 75a is significant energy flow talk less of a budget el cheapo with lower grade components.

I think you may have pushed the device beyond it's real hardware limits. It is not uncommon for the capacities and tolerances of el cheapos to be overstated.

sintolord:

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I abandoned the inverter. I now use Felicity and it's working as it should. Mind you, it's about 100k cheaper....

Well, I bought the inverter because seller told me Sorotec build there inverters with quality components.


I have a Tomzn voltage/current protective devise connected to my setup. Max 2500w load is allowed. Anything above, the device will trip off. If inverter is rated 3500w & I occasionally do close to 2500w. I still have a gap of 1000w. I am no where near the max capacity of inverter. Battery is 24v 15kwh, so it has nothing to do with the battery.

The day the inverter died with a loud bang, LG 1.5hp inverter compressor AC & Thermocool 219 liters (not exactly sure) freezer were the loads on it.

Bottom line is, inverter is poorly built. Probably built for Bangladeshi market

But I did mention the Axpert/Voltronic family and Deye as well boss

The Axpert family e.g Felicity, Zinox, Gennex, Sorotec, Phocos, Steca and all their grey market and rebrand ilk have some sort of solar then battery then utility priority built into them.

These also come with decent MPPTs built in.

The problem with the el cheapos is not a lack of features but rather scrimping on protections and critical ratings, poor isolation of the electronics and internals, flaky/buggy behaviour and a lack of robustness to deliver the promised performance long term.

toyeoye:


This makes sense! Strong selling point and reason to get a Victron inverter I guess. While we ponder on this option/save up to get one, we're on our own?

The Axpert family e.g Felicity, Zinox, Gennex, Sorotec, Phocos, Steca and all their grey market and rebrand ilk have some sort of solar then battery then utility priority built into them.

These also come with decent MPPTs built in.

The problem with the el cheapos is not a lack of features but rather scrimping on protections and critical ratings, poor isolation of the electronics and internals, flaky/buggy behaviour and a lack of robustness to deliver the promised performance long term.

toyeoye:


I have a famicare inverter and another external Yohako 100a. mppt CC and they don't seem to have a flexible ESS, SBU or similar algorithms Mr Niyi mentioned that will enable me to prioritise solar and batteries ahead of the grid.
The problem might not lie with your PVM but the inverter specs


I stand to be corrected

There is an algorithm called Energy Storage System (ESS) on the Victron side that prioritises solar and battery usage over grid. Grid is essentially a tap that can be opened full throttle or restricted as the user wishes - you could be running 3000w of loads and only using 120w of grid for example. The grid behaviour is SoC driven and the system can be set not to charge batteries from the grid.

The Axpert and Deye type inverters also have a more coarse algorithm called 'SBU priority' - there are also a couple of other iterations of this scheme. Essentially solar and battery usage come first then you set the low battery voltage level at which the system defaults to back to grid usage.

All these schemes let you manage your grid usage else with a basic inverter, grid is being used to run all loads and charge battery even when solar is available and sufficient at that time window which is a terrible waste. People manually switch off the mains or use a battery sensing relay + contactor to disconnect mains as they see fit.

One area where the Victron ESS excels is that you can set a miserly use of PHCN units and simultaneously set the system to very greedily gobble up available energy if your Gen is on - you get the best of both worlds as well as the ability to adjust these settings on the fly.

toyeoye:
Hello good people, I wonder why no one talks about the huge amount of units consumed through charging the batteries if your setup is tied to the grid.
Na die o! in my opinion doesn't make sense right now because the point of going solar is to save money eventually. ...

Please share your experiences, thanks

contease:


You are not alone bro... At some point, I had to look through the grid source lines after my meter to be sure neighbour's are not tapping my line, but of course, it's almost impossible because all cables are conduit just after the meter.

So seating down to analyse, what I see happening is that, we pay for grid even when no national grid.

Assuming you have 100% charge of your battery, and grid goes out to the time your battery becomes 50%, once grid is restored, your battery begins to charge while your appliances are also in use, this process draws so much current to fill in the gap on both the battery and the appliances..., putting off the inverter once grid is off or putting off basic appliances makes no sense otherwise what's the need to having a non stop power supply going solar... The only way out is to use the sun via panels

Sincerely, I think this is it... Let's wait for the SMEs to tell us more!