Victron Multi with Hub-1 5000W

[andrevh]

If there is a little bit of solar power available and the usage is more the the solar power available and the batteries are low with the grid available:

 

1 At which battery voltage does the Hub-1 switch over using  AGM/Gel  48V system.

2 Where can that setting be adjusted?

3  Is the Hub 1 assistant the only assistant required for this.

4 Feed back to the grid in Tshwane municipality, Would the UK: G83/2 grid code on the victron be correct and will it act as anti-islanding when required. 

 

 

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Hi Andre,

First off, hub-1 is dead. It's replaced by ESS. There is only one reason to keep using hub-1 in a new system and that would be if you wanted to use the disconnect-from-grid option, where the inverter runs disconnected (like an Axpert) rather than grid-interactive, and this can also be done using the other assistants (two relay assistants and a general flag assistant). So you don't need hub-1. See here for more info.

It does depend on whether you have a CCGX though. I know some setups used the Can->vebus cable (a very expensive cable) and had no ccgx in the system. Without a CCGX the rest of my answer doesn't apply, but I assume you have one? If not, there are affordable options: You can use the beaglebone black or the raspberry pi to do the job.

1 hour ago, andrevh said:

1 At which battery voltage does the Hub-1 switch over using  AGM/Gel  48V system.

It doesn't use voltage, it uses the SoC indication it gets from the BMV. If there is no BMV in the system, it can make a pretty good estimate by using information from the MPPT.

What ESS does is to attempt to keep your grid consumption at zero for as long as possible. It will run right up to full capacity from the batteries to keep grid import to zero and to avoid feedback (unless you configured it to feed back) until the battery reaches the minimum configured SoC. At this point it stops discharging the battery but it still feeds the available PV to the loads. Any surplus will charge the battery again. As long as demand outstrips supply, the battery simply remains at the minimum SoC. It will not discharge the battery any further but will import the difference from the grid.

If the battery remains in this state for too long, it will switch to forced charge mode and will charge from the grid.

1 hour ago, andrevh said:

2 Where can that setting be adjusted?

On the CCGX, under Settings->ESS. Of course not the voltage, but the minumum SoC.

1 hour ago, andrevh said:

3  Is the Hub 1 assistant the only assistant required for this.

The ESS assistant has to be loaded onto the inverter using Veconfigure. You may need other assistants if you have PV inverters tied to the output of the inverter, but in the general use case no other assistants is required.

1 hour ago, andrevh said:

4 Feed back to the grid in Tshwane municipality, Would the UK: G83/2 grid code on the victron be correct and will it act as anti-islanding when required. 

The MultiPlus does not have NRS097-2-1 certification. The new MultiGrid inverter is presently in the process of being certified (already has German and Australian certification), though I have no info on when that might be. However... (here comes the part where I rescue your shattered nerves), if you install a Ziehl UFR-1001e anti-islanding device before the multiplus, then it does comply with NRS097-2-1.

The UK code is not sufficient for South Africa. Our regulations require two disconnecting switches between the grid and the equipment, and only one of them is allowed to be an electronic switch. The other one must be physical (eg a contactor). The Multiplus only has one electronic disconnect, which is sufficient in the UK, but not here.

The UK program is however perfect when you use it along with the Ziehl anti-islanding. If you're going to wing it an bend the rules a little, which officially I cannot endorse and all that, then use the UK program.

I assume you already have the password required to change the grid code? You can get it by sending an email to service@victronenergy, if I recall.

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If you want a simpler setup that switches on voltage only, then you need no CCGX, no special cabling, and no anti-islanding. Simply disable the charger on the Charger tab, and configure your assistants like the image below.

Note that in this image, I have a switch wired to my temperature input so I can force the inverter to stay on the grid by closing the switch. Your inverter will have more analog inputs (three in total as I recall), so you may want to use one of those instead, or completely leave it out. It's very useful to have this switch though, prevents the inverter from going back and forth on a cloudy day.

This setup does not use any of the hub or ess assistants, it works exactly like the popular Axperts do, switching on voltage. You set the voltage when configuring the assistant.

If you have a BMV, you can wire the BMV relay to the analog input on the inverter to switch on SoC too. I'll go into detail if you need this info :-)

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And here is a screenshot from the CCGX, showing how it works. The AC loads are all powered and it's pushing back slightly (8W) while charging the batteries with the surplus.

 

[andrevh]

Thank you for feedback.

I used the simpler setup for a year.  What I had wrong is the auto syncing of the BMV. Although I waited till 57V and 20 min and .4 Amps, I think it synced to soon

I had it to only use 20% of the battery, having 80% left inside battery.

The resync caused the batteries to discharge more every time.  (My assumptions, others say batteries just don't last that long. Mine is a year old and went through the 40 degrees heat wave we had.)

Second problem I had, (could not afford it at the time) was battery balancers.  I do have it now.

I have 4 banks with 4 batteries.  On each bank one of the batteries went to 10.n V while the others were at 12.n V,  therefor the change in setup.

 

 

So, now state of charge is meaningless because the Voltage goes to low at 80%. (My assumption)

The ESS setup  (did not know about it, till now) does not give the option not to feedback to the grid.That's why I want to use Hub-1, but without any devices if using the British grid is technically safe, that is an option

I do have all the required hardware for Hub1. CGX Monitor BMV Monitor, 18 CIS panels and 70 Amp charge controller and VE Bus to CAN cable

The firmware on it was to old but I got it updated to be able to use Hub 1.

 

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16 minutes ago, andrevh said:

The ESS setup  (did not know about it, till now) does not give the option not to feedback to the grid.

It does! This is the default setup. See attached image. You can either use the meter inside the multiplus, or you can use an external modbus power meter. If you use the one inside the multiplus, it won't feed back at all and all power goes only to the output of the inverter, but in a grid-interactive way so that a shortage can be imported from the grid. The external modbus meter option is used when you have loads that are not on the output of the inverter. You put the meter at the entry point of your home (just after your municipal meter) and it then pushes back just enough power to cancel out your loads but not so much that it pushes back into the grid. Unless you move that slider as in the image.

Multi should have firmware version 408. On the CCGX you want to run the latest release (not the testing release). There is a tiny problem with the latest testing release. I run the testing release at home at the moment: the problems are that when it hits the minimum SoC it doesn't stop discharging, I think a small calculation fault causes it to continue discharging at a low rate. I think this happens because the control loop has to do a AC-power to DC-current calculation and factor in inverter efficiency, and that calculation overshoots slightly. The guys up North know about it.

There is also a problem with the "Keep batteries charged" mode. I think it is also related to the loop calculation. Once again, this only affects the latest testing release.

The option that works best at the moment is "Optimized (with BatteryLife)". I presently use "Optimized (without BatteryLife)" with a 90% limit, because I have enough loads in the day that I can consume my PV directly give or take 10% (though that will change, I have more PV panels on the way).

I don't know if you should still use the can->vebus cable. This cable bridges the two busses (vebus and canbus) so that the inverter can address the mppt. In the latest version the CCGX sets up a dummy inverter that can talk to the MPPT, and relays info from the real one, acting like a proxy. I think you should probably leave the cable out if you're going to use ESS.

Also, regarding your batteries, it depends what you have there. If its Lead Calcium 100Ah jobbies, that sounds about right. After a year some of them may well start failing. Failing batteries may also progressively refuse to accept charge causing the voltage to rise and the current to drop, causing the BMV to auto-sync prematurely. In other words, I think the BMV is working perfectly, its just that your bank no longer has the original capacity. If the bank only has say 40% left of the original capacity, then taking it down to 80% SoC (calculated by original capacity) is really 50% DoD.

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54 minutes ago, andrevh said:

What I had wrong is the auto syncing of the BMV. Although I waited till 57V and 20 min and .4 Amps, I think it synced to soon

I don't think you did anything wrong. I have mine set to 1% (which is 2A for my bank) and 15 minutes, syncing above 27V (54V in your case). It's just about bang-on every day, going to over 98% every time before it syncs (which happens infrequently, it doesn't sync every day, maybe once a week).

If I understand you correctly and you have 4 strings of 4 batteries (16 batteries total), and assuming they are the 100Ah variety (don't ask me why I suspect this), you have a 400Ah bank there. If its only accepting 400mA by the time you sync... and it is not full... something is seriously wrong.

[andrevh]

Unfortunately, I have 16  Omni Power 260Ah 

OmniPower Fully-Sealed Deep Cycle AGM+Gel VRLA Maintenance Free Solar Batteries.

 

I just want to get out off them what is left for as long as possible. That's why the feedback to grid can also help to recover some cost.

I do have a mechanical meter but no other external equipment.

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1 minute ago, andrevh said:

Omni Power 260Ah

Those are 200Ah batteries (at C20), the 260Ah rating is for C100.

Still means you have a 800Ah bank there.

Other than moving to ESS, I would also recommend that you find the bad batteries and reconfigure the remaining ones to three or even two strings. As it stands now, the bad batteries will take down whatever good remains in those that are still alive.

ESS allows you to limit the discharge rate on the batteries, so you can set it to a lower value (taking the rest from the grid) and avoid pulling them down too low. You can see the slider in the image right at the bottom :-)

[andrevh]

Quote

 If its only accepting 400mA by the time you sync... and it is not full... something is seriously wrong.

I think the problem might be, because the battery might be in absorption phase for the amount of time required, but because I am using almost everything from the Solar array, the remaining amps going into the battery is the .4 Amps that triggers the sync????

[andrevh]

Quote

Other than moving to ESS, I would also recommend that you find the bad batteries and reconfigure the remaining ones to three or even two strings. As it stands now, the bad batteries will take down whatever good remains in those that are still alive.

I took all four out and recycled them individually on a 12 V charger and run them down on a separate inverter  just powering my study room. (+-400W)

On each the first use took 10 minutes till the (seperate) inverter shut down but after 3 cycles I got an hour out of them.

I presume they are fine again.

[andrevh]

Quote

Those are 200Ah batteries (at C20), the 260Ah rating is for C100.

This then is the part that I missed, but was under the impression that the Peukert exponent took care of that.

 

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20 minutes ago, andrevh said:

I think the problem might be, because the battery might be in absorption phase for the amount of time required, but because I am using almost everything from the Solar array, the remaining amps going into the battery is the .4 Amps that triggers the sync????

Yes, that's sometimes a problem. You normally solve it by setting a longer "charged" time.

It's unusual that you could balance your loads so exactly (not just once, but frequently) that the batteries sit at float/absorption and yet have only 400mA left. In my experience, you either use your PV so effectively that it fails to raise the voltage on the batteries (which should sit around 52V or lower in that condition), or you have at least a few ampere surplus. To have it balanced that finely for more than 15 minutes straight... no I don't buy it. Not as high as you have the voltage set.

2 minutes ago, andrevh said:

This then is the part that I missed, but was under the impression that the Peukert exponent took care of that.

There is an example in the manual. I think the one you enter should be the C20 rate, and then you calculate the Peukert exponent by using the second value you have available (preferably a C10 value). If you used 260Ah as the C20 rate, but you still only used the top 20% (of 260), that's still no reason for them to die within a year.

[andrevh]

8. Comparison to Hub Assistants

 

8.1 Hub-1 Assistant -> ESS Assistant

 

Policies

Hub-1 policies that are deprecated in favor of ESS:

• Policy 1: Connected to mains, feedback: use ESS and enable solar charger feed-in.
• Policy 2: Keep batteries charged: Use ESS, select the “Keep batteries charged” mode. And enable “Feed-in excess solarcharger power”
• Policy 4: Prevent feeding energy to the grid: two options, one use ESS and do not enable Solarcharger excess feed-in and it will be always be connected to the grid. Or, use the Virtual Switch with ignore AC-Input.
• Policy 5: Connected to mains, no feedback: Use ESS, select the “Keep batteries charged” mode.

Above leaves us one policy where the Hub-1 Assistant can do things that ESS cannot.

• Policy 3: Disconnect from the mains when possible: Keep Hub-1 Assistant or, often a simpler and therefor better solution, use the Virtual Switch with Ignore AC-Input.

 

 

This is why I will use Hub-1 until grid feedback is official sorted out.

But then the original 2 questions:

 

1) Using Hub 1 battery low cut-off switch back to mains setting.I assume by now it is the standard Inverter tab  DC Input low shutdown.

 

2) Without any external anti Islanding device, except for the UK Region code inside the inverter,   would it be technically (ignoring regulations) safe to use.

 

 

 

[andrevh]

Quote

There is an example in the manual. I think the one you enter should be the C20 rate, and then you calculate the Peukert exponent by using the second value you have available (preferably a C10 value). If you used 260Ah as the C20 rate, but you still only used the top 20% (of 260), that's still no reason for them to die within a year.

That's why I think the battery balancer would have solved the issue.   Ok, they are not completely dead, just a bit less what I expected.

Obviously the 4 10V  batteries took the overall voltage down by 2V getting to a battery low alarm faster.

But those 4 are now on a separate bank, again part of the system after the reviving of them

 

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5 minutes ago, andrevh said:

1) Using Hub 1 battery low cut-off switch back to mains setting.I assume by now it is the standard Inverter tab  DC Input low shutdown.

No, I believe when you configure the hub-1 assistant and you choose policy 3, then it asks for the voltages you want to use. It's separate from the DC input low shutdown. The latter is a safety function meant to protect the batteries and is usually set fairly low (around 42V or so). Your switch-back-to-mains voltage should be much higher. I used to use 24.7V (or 49.4V for you), which at my typical loads was about 80% SoC.

The image I posted above is similar to the "Virtual Switch" the documentation mentions. VS was used in the older 1xx firmware versions. The 2xx and 3xx ones use assistants only, and the 4xx firmware can do both (but not at the same time).

9 minutes ago, andrevh said:

2) Without any external anti Islanding device, except for the UK Region code inside the inverter,   would it be technically (ignoring regulations) safe to use.

Technically, when you ignore regulations, it can't be called safe. Honestly, this is a public forum, I cannot in good conscience tell all the world to ignore the regulations. I personally believe it is safe to use, I mean seriously, those Whiney health-and-safety Brits are okay with it, but that's as far as I'll go on a public forum :-)

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Just to be clear: Hub-1 policy 3 is in essence no different from using one of the other switching mechanisms, be it the relay assistant stack as per image above, or using VirtualSwitch. If you already have trouble with that setup, hub-1 is not going to help. If you're going to use one of the other policies, and you already have a CCGX, you might as well go with ESS as the others are deprecated.

[andrevh]

Quote

No, I believe when you configure the hub-1 assistant and you choose policy 3, then it asks for the voltages you want to use

I have gone through options feedback and do not feedback.

The options here are the only available.

Yes, I will do the ESS option, but will need to do more reading on it and what they say you do need an anti islanding device can delay its implementation here.

[andrevh]

Quote

Just to be clear: Hub-1 policy 3 is in essence no different from using one of the other switching mechanisms, be it the relay assistant stack as per image above, or using VirtualSwitch. If you already have trouble with that setup, hub-1 is not going to help. If you're going to use one of the other policies, and you already have a CCGX, you might as well go with ESS as the others are deprecated.

Is there a cabling diagram for ESS somewhere as there is for Hub-1

 

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It seems to me the hub-1 assistant has changed. I seem to recall it had voltage settings you could configure.

It might have something to do with a new feature called dynamic cut-off, which attempts to use a lower voltage for cut-off based on the load. I know the old hub-4 assistant also used the voltage on the Inverter tab, but with dynamic cut-off. Perhaps it is as you say.

The best place to start is probably the old hub4 page and also the venus 2.0 release post. That shows a connection block diagram. The various PV parts in dotted lines are all optional, you can have more than one of them, or even none at all (in cases where you want to do peak shifting for example).

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Also, this webinar.

[andrevh]

Thanks for all the feedback.

I need to upgrade my CGX Controller, just got a SD card to do it.

Just to confirm, you did mention earlier, the SOLAR Control must go directly to the CGX again , the same way I used it with the relay setup and not through VE Bus to CAN interface?

 

 

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8 minutes ago, andrevh said:

Just to confirm, you did mention earlier, the SOLAR Control must go directly to the CGX again , the same way I used it with the relay setup and not through VE Bus to CAN interface?

I assume you have a the 150/70 MPPT with the canbus connection? You use a RJ45 cable to connect one of the canbus ports on the MPPT to one of the canbus ports on the CCGX. Leave the vebus-canbus cable out of the system completely. Remember to terminate the canbus by plugging terminators into the open ports on the MPPT and the CCGX. The CCGX ships with two terminators.

When it is all working, the MPPT will show Hub-1 on its LCD. That doesn't mean it is really in Hub-1, it just means the Multi (via the CCGX) is in charge of charge parameters. On the canbus controllers it can only control the charge voltage and not the charge current, so all it does is tell the MPPT what voltage to aim for. That way you can set the charge parameters in only one place and all your MPPTs (if you have more than one) work in tandem.

You should still configure the MPPT with the right voltages and set a safe current limit, because if something goes wrong and comms with the CCGX break down, the MPPT will go back to that configuration.

[andrevh]

I need to update the firmware of the multi to proceed, but yes ESS makes especially that you can adjust it not to use all the battery as with the relay setting and Hub-1 when main available.

At the moment I am running Hub-1.

 

Battery condition:

 

Battery monitor reads 88%    Battery voltage = 49.2  and Amps being withdrawn = 30.7 Amps.

 

Is this the correct voltage or should it be higher.     ( 4 x 4 x 12 V) - 260 AH  total = 1040 AH battery bank.

 

 

 

 

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3 hours ago, andrevh said:

Is this the correct voltage or should it be higher.

Difficult to say. With a battery of that size charged to over 85%, and assuming equal distribution of current, you're talking a 12.3V battery at 7.5A discharge. Doesn't sound completely wrong to me. It would depend what happens as it discharges further, I'd expect it to stay well above 48V until it drops below 50% SoC at least.

On my batteries I get 24.2 (48.4V) at around 65% SoC while drawing around 10A.