I have now assembled all the components, Multiplus 11, MPPT 450/100, Cerbo, Touch Screen 70.
Lynx distributor wired up but not comms cables. Not sure what the next step I should take. Having seen a video of the Multiplus being configured as a stand alone job I wonder if that should be the next step. I have yet to install the BMZ battery it is the last of the components and I am not sure how best to do this and at what stage as that will need to be set up with its own parameters. From what I can make out the battery is configured within the inverter configuration and elsewhere but does the battery need to be in place and wired in for this?
It has become a bit murky at the moment and I have not managed to find a way to go forward from here.
Yes, the multiplus needs to be configured before any AC connections are turned on. To do this the battery MUST be connected first. Use a Mk3 and VE configure to do this.
So finish the installation of the battery, and make sure that you have a stable output voltage. Connect the BMS data to the cerbo, and access the Cerbo to configure the BMS connection.
Configure the inverter, then connect the inverter VE bus to the cerbo.
Thanks Mike. That sounds like a good method but I am concerned how much pre-connections I will have to do. My battery needs a continuous communication from the inverter otherwise it will switch off after 10 or 20 mins. That means I need to connect that up via the Cerbo et al. The Victron video demonstration on a bench looks like it is AC powered and no battery attached. I have downloaded the Connect app and it lists the equipment covered. My Multiplus 48/8000/110-100 230V is not listed so wonder if it is covered. I had a play with the demo using the next one down the 5000VA to get a feel for it. Changing the values and working through it looks easy enough the issue for me is I do not know enough about what to change on a lot of the values. My BMZ battery is well documented so can input those values and I am ok on the AC side of things.
You need a resistor or similar (lamp) between the batteries and inverter, to avoid a spark when the capacitors fill up. Unless the batt bank is huge.
Why would the batteries shutdown after 10-20 mins? What model do you have?
Thank you. I do not know why it switches off safety or conservation or similar? Must reside in the BMS I guess. The battery is a BMZ ESS X 10 kW. I chose a Victron replacement when my Delios inverter failed and company gone into receivership. VE was only one of 2 makes I could replace it with, that could be configured with the battery. I have checked the manual and it switches off after 20 mins not 10 after loss of inverter communication. I only found out when after an outage that the battery had switched off. I did not have critical loads set up which would have kept it going. I would prefer to configure the inverter using AC to avoid battery complications when configuring. It looks like I also need to download ESS to the inverter but looking at the Connect software I have downloaded it does not look like Connect 3, that is shown on an ESS video I looked at. My version of connect has no tabs and I cannot locate connect v 3. Maybe it show different when inverter is connected up to the PC and connect.
@sylulu yes, this is for safety.
IF you connect the remote voltage sensing of the inverter to the battery bus, then this path includes the precharge resistors. Some battery management systems also include a ‘soft start’ mechanism, where the BMS drops about 1- 2A (current limited) onto the battery bus when turned on. For batteries like this, the external precharge is not required (!) BUT all of the inverters and solar charge controllers must be connected to the battery bus before the first battery is started.
The Cerbo will provide the ‘keep awake’ signal to the battery with or without the inverter connected to the Cerbo.
If the bank is large then you still have the problem. This (precharge requirement) is Voltage related, and needed for 48V, a good idea for 24V and normally ignored for 12V.
NO!! you must not do that. The inverter configuration out of the box is ok for connection to the battery. Then as you set up the inverter, you start by configuring the AC parameters. The Mk3 connects to the inverter and normally to a laptop for configuration, this does use different software (VE configure) than VE Connect , However VE configure (latest versions will work for single phase cases). If you have only a phone to configure with, you may be better off with a ve bus to bluetooth adapter if they make one - or Mk3 to USB-C.
From a Victron specialist, I have been told because of the high demand on the juice to charge up the capacitors, the answer is to power up the inverter 1st swith AC so that there is “less” demand on the battery when that is switched on to the system. To connect battery 1st cause a surge into the inverter. After about 30 secs the battery can be switched on. With the BMZ it needs constant communication with the inverter otherwise the internal BMS switches it off.
EVERY INVERTER has a printed warning on the front cover “Disconnect the supply before making or breaking the connection to the battery.”
To prevent the inrush surge, the remote voltage sensing connections should be made and energised BEFORE the main battery power is applied. There are built in current limiting resistors. Making the remote voltage sense connection allows the main capacitors to pre-charge.
Your so called “victron specialist” should read the manual more carefully.
Some lithium batteries have built in slow start circuits, many do not. For 12V systems, this is usually ignored. For 48V systems, this inrush current can be harmful so the precharge wiring is essential.
The Cerbo provides the CAN keep alive signal to the BMS,not the inverter, so setting up the Cerbo - BMS communications should be a first, then power up the inverter.
You are very correct and it makes sense. After my post and late last evening it occured to me that the out of the box settings for the 8kVA current is up to 50A. If on power up it wants to take more than my supply of 32A then my RCBO will trip. The AC input limit I think need to be sorted 1st. Maybe the approach intended was to power up the inverter to charge up then turn off and then connect the battery that might make sense but the “turn off” was not included in his email.
I did know about this. Is it 4.5.5 Voltage sense in the manual? I had picked up somewhere that the multiplus has a soft start facility but could not verify it. Would this be it? So bridging the terminals + & - will prevent an inrush surge?. The manual desctibes it as a compensation for potential cable losses during charging. Am I loooking in the right place.
The battery BMS may have soft start but I cannot confirm that either.
I have consulted the procedure used when I commissioned the BMZ battery to the previous inverter. So I was thinking on the following for connecting to the Multiplus.
Condition, all comms cables connected. Inverter off. MPPT strings isolated.
- Connect battery.
- Switch on battery the BMZ manual says it takes 30 secs to 2 mins to pre charge the capacitors
depending on Inverter type. - The Cerbo should power-up and maintain the comms to the battery.
- After 2 mins the Inverter can start to be configured on battery.
- Post configuring the inverter could then be switched on as there will then be no danger of exceeding 32A as the default 50 will have been changed.
Would that be a good approach?
When you are setting up, the inverter gets turned on by it’s small switch. It will power up into invert mode first. You leave the AC in breaker and AC out breaker OPEN (off) at this stage. Then the inverter will stay in invert mode, and only take a small current from the battery. At this time, you can then configure the inverter grid,charger and battery parameters. You cannot communicate with the inverter until it is switched on.
After configuring the inverter, the Mk3 is disconnected and the VE-bus from the inverter is connected to the Cerbo.
I would follow the advice of @MikeD Just to add that though I have never had to use it, you can pre-charge the capacitors by connecting and switching on the PV MPPTs. First. This is apparently covered by warranty. But I think you still need the batteries to program the inverter.
Doing it on AC can “work” but it can have unpredictable or even adverse consequences. It is discouraged and not covered by warranty.
Thank you. What is not to like about the step procedure I have outlined above. The configuration is done on the battery. From the previous set up I had the battery was used to precharge the capacitors. It is in the BMZ manual. The previous inverter was a similar size to the multiplus so why would not connecting the battery 1st and do the congiuration. That avoids my concern of inverter trying to draw more than 32A.
Your procedure looks good, assuming your batteries can support the inverter. It’s not a great idea to compare inverters that way as their surge demands and capacitor capacity can be quite different. But it’s better to try the batteries first.
Thank you all, l was sitting on my ticket all the time. By use of Ai search that delved into the Victron and BMZ manuals have confirmed that the BMZ has a pre charge protocol as the first squence of powering the inverter as I previously thought. On the Inverter side the power up to be done with the Multiplus 11 switched off. When the main BMZ contactors have operated a green LED lights inside the battery casing to indicate pre charge has completed and normal procedure can continue. So this confirms what I thought a couple of days ago. Best to be sure though, will proceed with this. When successful will close off the post.
Deleted due to other info.
Deleted due to other info. Will do new posting,