[Solved] How to connect the OFF-GRID 1-F inverter in a 3-P installation with a circuit by

The topic basically concerns a situation where the hybrid inverter is too weak to transfer the load of the entire house. In my case, the kitchen can draw 4 kW instantly and the AZO Digital ESB-6kW-24V inverter, according to the product card and looking at the contacts, will hardly transfer 3 kW? Therefore, I developed a connection scheme so as to use the energy in the off-grid system, but not to overload the inverter. As for the scheme, the installation is of the TN-C type, so I also have to "convert it" from the meter to TN-CS. Maybe someone will find it useful, or maybe someone will notice a mistake somewhere and we will fix it so that it will be useful to me and others. I also have a dilemma whether to connect the earth electrode through the inverter with the existing network (the dotted line with the description should be connected). Regards

rademenes787 wrote:

I also have a dilemma whether to connect the earth electrode through the inverter with the existing network (place with a dashed line with the description CONNECT)

If the PE terminal is described, then yes. At the output of the inverter, are you sure there is only L and N without PE? If so, there will be some kind of IT arrangement, unless in the middle PE and N connect?
I want to do something similar at home only on the Growatt inverter, once that 5kW of continuous power has more options, including the choice of charging hours from the battery network. And whether output N is connected to PE is configured in parameters. Maybe yours is like that too?

Kosmos99 There is only L and N at the output of the inverter, but there is a grounding screw on the housing. I don't know what's inside, because I didn't disassemble the inverter, I guess rather yes. I don't know its capabilities too much, because I haven't turned it on yet, and the instructions are so-so. I am before the construction / reconstruction of the electrical installation. Today I did the mountaineering and just fitted the rails. Maybe in the future I will change to Growatt, if I am satisfied with the overall performance of the system. I'm a bit worried about the direction of the roof to the sun, because there is no shadow at all, but the south-west 45 degrees vertically gives me only sun from 11am to evening...

rademenes787 wrote:

there is a ground screw on the case.

That is, it is only protection against electric shock in the event of a puncture.

How many Kwp panels, what battery?

8 panels of 370 watts = 2960. I don't know what kind of batteries yet. I'm planning 100-200 Ah at the beginning. This inverter also works without batteries. I'm just looking for the right ones, well, it all depends on the wallet. The best are LiPo4, i.e. Lithium Phosphate (2300 for a piece of 100Ah), Then acid-carbon (about 1400 for 100 Ah), then AGM (about 750 for 100Ah). So you see, there's room for dilemmas. In general, this system is designed to "support" or "reduce" current electricity bills, as energy storage pays off on average considering battery prices. In the background, it is to serve as the maintenance of the necessary minimum of devices, i.e. a central heating furnace + pumps, lighting and a water pump. So 200 Ah should be enough. Better 200 Ah because there is a lower discharge level, which means less battery consumption.. long to talk

For me, the main purpose of using this system is convenient backup power, and the small storage function is just an add-on. I want to give 2.2 kW to the offgrid, and I have 9kW on the ongrid, which is why the option when the batteries can be charged from the network is so important. It comes out much cheaper than a hybrid inverter. The more so that with the hybrid, expensive Lithium batteries must be used in most cases.

Who said they have to be Lithium, they don't have to be, only that Lithium is the best. It also depends on the degree of discharge. If 200Ah is enough to discharge up to 80% of carbon-acid or AGM batteries, they will not even have time to sulfate. Hybrid gives straight from the panels and if there is not enough electricity, it selects the rest from the network, when not in use, it will replenish the batteries or heat the water in the boiler. Even though you can't store too much, I believe that the benefits are many. On-grid, in my opinion, does not make much sense in the future, because as with everything in today's world, the merciful rulers will make sure that you do not benefit. You will produce electricity and pay for it, ha! It is enough to notice how we all switched from light bulbs and devices to energy-saving ones, and the bills are almost the same as before the change ... Who earned?

When writing about the hybrid, I meant inverters (e.g. Fronius Gen, Fronius Hybrid, Growatt MOD or Huawei Sun) that can give excess energy to the grid. The downside of offgrid is that if we do not consume energy and have charged batteries, we do not use the power of the panels to the full. Hybrid inverters do not have this problem, because they give the surplus to the grid, but their price is specific.
It is more profitable to use one on and offgrid than hybrids. The more so if the option of charging the battery from the network is set to the daytime hours when the ongrid works, then we use the panels as much as we need, and we do not lose their production. The fact that there is a minimum loss because the panels go to ongrid, and from ongrid to AC offgrid.
In my situation, the cost of a hybrid inverter plus a 5kWh lithium battery (you won't connect another) and the ATS system is about PLN 30,000.
Adding off the grid and the AGM battery will come out to about 8,000, so the difference is concrete, the ATS system is unnecessary, and the switching time is much shorter (a fraction of a second) than in the case of a hybrid (over a minute).

Here, a hybrid is a combination of own energy production with supplementary selection from the grid in the event of too low production. However, in the case of surpluses - you can always connect a buffer tank and a heater. I think it's just a matter of choosing the number of panels to receive. As for the fear of wasted surplus ... I will ask the opposite, and how much is "wasted" energy from the sun not received by any panel? I approach it this way, I need it, I use it, and if not, I don't. By no means am I independent of the whims of the supplier. I also don't want their two-way smart meters and usurious rules, because in a moment it will turn out that people connected to the grid will pay for the energy they produce. The solution I propose is the cheapest possible and gives some psychological comfort, I will always produce something sometimes more or less, but it is there.

rademenes787 wrote:

As for the fear of wasted surplus ... I will ask the opposite, and how much is "wasted" energy from the sun not received by any panel? I approach it this way, I need it, I use it, and if not, I don't.

It's not about wasted energy from the sun, it's about money spent on panels that are not fully used.
Now it works for everyone, because it is new, all panel manufacturers supposedly give an 80% guarantee after 25 years, but it is not known how it will actually work out. I rather doubt that this guarantee is enforceable, note that some panels can not be obtained after a few months. Now virtually no one installs polycrystalline, and three years ago it was a standard, and mono a novelty. I am of the opinion that the refund should be as quick as possible, and the current on-grid settlement conditions are really good. OFF-Grid is not profitable, but it is convenient in the event of a power outage from the network, the switching is at the level of the UPS, i.e. it is not noticeable and there is no need for significant interference in the switchgear, nor a costly inverter or ATS system.

Yes, it all depends on the intention. Your intention is reimbursement and profit, mine is my own energy security. When it comes to unused panels, once again, you can choose the size of the system so as to use them to the full. It is enough to know the maximum power (the amount of energy produced) and adjust it to the number of receivers. The batteries are only in such an amount that they can last overnight, supporting, for example, pumps from the stove and the refrigerator. On the other hand, the rest of the energy, apart from the one consumed during the day, consists of buffer tanks and boilers.

rademenes787 wrote:

Yes, it all depends on the intention. Your intention is reimbursement and profit, mine is my own energy security.

What is electrical safety, as you write:

rademenes787 wrote:

The batteries are only in such an amount that they can last overnight, supporting, for example, pumps from the stove and the refrigerator

Cloudy or winter day with snow and the next day there is already a problem. In addition, the panels must be oversized so that they can charge the batteries on a short winter day.

That's why this topic was created, and that's why you need to experiment. If in the face of total lack of energy I have options like the above or nothing, then I take what is. Others will sit by the candle. From poverty you can let go of the generator, although this option is rather not satisfactory to me. I would say that you can attach a wind turbine, but I will soon hear that there will be a cloudy and windless day of the year ... Really, it's probably not very reasonable to drop everything because such a day will come ... I would rather ask for constructive criticism, because it would be to throw away 30 thousand zlotys and It's a bit naive these days to expect it to pay back in 10 years. Especially since if there is a power failure, what are the options then? After all, you can see with the naked eye what these psychopaths in the governments of the world are preparing for people ... What we will be vainly beating here, time will show. As of today, I am slowly finishing the installation and will go to the testing phase. I have 3kwp on the roof, 100ah/24v battery and I'm still thinking about choosing a heater. I don't even know what my Chinese inverter actually has. Regards

Interesting ;-)

rademenes787 wrote:

That's why this topic was created, and that's why you need to experiment.

a few sentences later:

rademenes787 wrote:

What we will be here in vain to foam, only time will tell.

rademenes787 wrote:

I have 3kwp on the roof, 100ah/24v battery

In my opinion, the capacity of the battery is much too small in relation to the power of the panels. If they are AGM, then discharging them to 70% capacity is max. So you really have 0.8kWh at your disposal. A 1.5kW heater in a 100l boiler heats water in 3 hours. 3kW panels will be able to produce 10kWh a day in April - September. Can you manage most of it?

rademenes787 wrote:

I would rather ask for constructive criticism, because it would be to throw away PLN 30,000 and count on it to pay back after 10 years

No criticism, in this case you can't count on a refund at all, but you won't have comfort with this battery capacity either. Even if you set the discharge level to 50%, you only have 1.2 kWh at your disposal with new batteries, then it will decrease drastically. In the best conditions, AGMs have a declared durability of 10-12 years, but in buffer operation and at a temperature of 20C. With a cyclic discharge to 50%, it is only about 400 cycles, which means after a year you have only 60% of the capacity. Of course, assuming that there will be no cases of deeper discharges along the way.

My opinion is that in this system you should have at least 8, and preferably 12 batteries like you have and a bit of a mistake that the inverter is 24V, not 48. With more batteries, there will be no need for deep discharge, so you can count on significantly longer life.

I agree about the batteries BUT:
1. The batteries are the Carbon series, so they are slightly more resistant
2. I'm going to expand them as needed, but only by another 100 Ah
3. I do not intend to use the batteries on a daily basis only in the event of a lack of energy, and then:
4. They are only intended to hold the most important things: furnace and pump electronics, water pumps, fridge/freezers, and possibly a few light bulbs. Here, from the calculations, I got about 4.5 to 9 hours on the batteries, depending on the load

"No criticism, in this case you can't count on a refund at all, but you won't have comfort with this battery capacity either."

As I emphasize for the second time, I do not count on any return, unlike all the rest of the enthusiasts of renewable sources. last minute ps... Turów sold... so our safety is = 0. I want to put the meat in cans or jars on time if the merciful ruler surprises us and it may not freeze due to the fact that heating requires electricity... Any kilowatt gain there is just a minor good.
Returning to the batteries, I want to set it to charge from the battery only when there is no power ...
Since I am supposed to have such surpluses as my colleague writes, then the batteries will be charged and I will still push this heater somewhere.

"...a bit of a mistake that the inverter is 24V and not 48."

Well, I know it was a mistake, but the handle has already fallen. Today I would buy the most powerful model because I would also have no problem with the load on the inverter contacts, so I had to separate the kitchen from the rest of the installation

Welcome back. Well, I'm trying to turn on the system. Unfortunately, at the first moment the phase switch started to go crazy and switch contacts in fractions of a second "jump on them" so I disconnected the solar mode and it went back to normal. I set the PV power mode on the inverter because it was on BYPASS. I also disconnected the kitchen because I thought maybe there was a short circuit through the kitchen ... So now I switched the power mode to the one from the inverter and ... it worked for 3 seconds and the phase switch exploded. It exploded like firecrackers for the new year, I quickly disconnected the power. Phase switch fried and now I wonder what went wrong...

I do not know how you connected this ESB to the current circuit, I also had OffGrid with the same inverter at one time, connected to a separate circuit and there were no "circuses".

I had the connection to the inverter directly from the main switchgear from the bus where the output from the meter was connected, in your case one of the phases, of course through an additional small switchboard with protections.

In the main switchboard, I separated the circuit that is to be powered by the PV installation, i.e. I disconnected its power from the main switchboard, the separated circuit was connected to the return cable from the inverter and everything worked as it should.

This was my philosophy with a separate circuit, such separate circuits can be two or even more, then each can be protected with an overcurrent protection in a small switchgear I wrote about.

It's strange to me that something is wrong with you .

that's how I more or less connected ... in tracking the babola I have already detected one (the only one?). I connected the "N" wire of the phase switch from the N bus of the inverter instead of the mains. I'm still looking to see if I missed something. So far, the phase switch for PLN 300 has gone up in smoke, unless I can fix it (Apparently the PN274PN system, a few varistors and probably something else was on fire)

Added after 17 [minutes]:

rokbok wrote:

I do not know how you connected this ESB to the current circuit, I also had OffGrid with the same inverter at one time, connected to a separate circuit and there were no "circuses".

I had the connection to the inverter directly from the main switchgear from the bus where the output from the meter was connected, in your case one of the phases, of course through an additional small switchboard with protections.

In the main switchboard, I separated the circuit that is to be powered by the PV installation, i.e. I disconnected its power from the main switchboard, the separated circuit was connected to the return cable from the inverter and everything worked as it should.

This was my philosophy with a separate circuit, such separate circuits can be two or even more, then each can be protected with an overcurrent protection in a small switchgear I wrote about.

It's strange to me that something is wrong with you .

And since only N and L come out of the inverter, what did you do with the PE protective cable from the devices? In my case, it is fastened in the box with the N strip as I converted the TN-C system I have to TNC-S in this way. Now I'm wondering if this fact, i.e. I receive L and N from the inverter and at the same time PE bridged with the N network, does not affect the system?

For me, as the old cottage is an installation of only L and N, the pins in the sockets are connected to N, I made a pin earthing for the PE inverter.

rokbok wrote:

for the PE of the inverter, I made a pin earthing

Why so?

kosmos99 wrote:

Why so?

Expand the question/thought.

Why does the inverter housing have a separate earth ground not connected to PEN?
At least that's how I understood it.

rokbok wrote:

For me, as the cottage is old, it is only an L and N installation

So that the inverter, currently On Grid, does not report a grounding error, he got his own individual / personal, this is a distinction for him .

kosmos99 wrote:

Why does the inverter housing have a separate earth ground not connected to PEN?
At least that's how I understood it.

the housing is like a housing, but the electronics inside also has a PE contact, so what should I connect a separate ground to it, and take L and N from the mains?

rademenes787 wrote:

the housing is like a housing, but the electronics inside also has a PE contact, so what should I connect a separate ground to it, and take L and N from the mains?

The fact that I specially made an earth wire for the inverter is only because my installation in the building is only phase and neutral, no ground wire, old shack, the regulations were completely different in those days, so to connect the inverter to PE I had to do it.

In your case, there is no such need, you have an earth electrode in your installation, so you connect to it.

rokbok wrote:

rademenes787 wrote:

the housing is like a housing, but the electronics inside also has a PE contact, so what should I connect a separate ground to it, and take L and N from the mains?

The fact that I specially made an earth wire for the inverter is only because my installation in the building is only phase and neutral, no ground wire, old shack, the regulations were completely different in those days, so to connect the inverter to PE I had to do it.

In your case, there is no such need, you have an earth electrode in your installation, so you connect to it.

Not quite so ... I have a TN-C installation, so the neutral in the box was made on PEN so that it was TN-CS ... so probably like you

I fired without the phase switch, with small corrections and so far it works ... I don't know 100 yet if this correction is everything or something else. A little afraid to install a new phase switch ... However, however, the system seems to work. However, I have not deciphered the inverter yet and I have not connected the OW batteries and the new grounding from the panels ...

Your phase switch probably burned out because it did not have a N-ki, the inverter turns on the output after a while, and I cannot turn it on after the switch switched the phase every now and then. If N is from before the inverter, it will be ok.

Sounds reasonable, tomorrow I'm connecting a new phase switch ... it will cry if this one burns out too ...
I also have another dilemma - it's about the fuse for the batteries. In the instructions, they write about the thickness of the cables and give 142A, but it is not known what it is about, while the maximum charging current is somewhere around 60-70 A ... So what fuse should be installed in the end, they confused me a bit

rademenes787 wrote:

... a bit of a mistake that the inverter is 24V and not 48.

I have 3 converters (ultimately there will be 4) for 12V and I think that I don't need either 24V or 48V. Each converter has its own, as I write it, service area. I don't load one device.
The system is running nice ... fridge, automatic machine, computer, TV, lighting and other ... batteries practically constantly charged .. this is a support, not a power factory.
And the goal as a friend ... that it has to work practically everything from the furnace up ...