New install with a couple of issues

DIY
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1

I’ve got a “brand new” install of 2 Quattro 24/5000-12 units connected to a Cerbo GX in a motorhome. These are replacing 2 Magnum Inverter/Chargers of slightly smaller size but older technology, thus the brand new in quotes.

The connections, other than the network cable between the units and the Cerbo are the same from old to new. Relatively straight forward install. Disconnect the various AC and DC wires and reconnect them to the appropriate new points. Both Quattros are mounted on the factory hanger in a vertical orientation.

They’re charging 10 (ten) 4D agm batteries when connected to shore power, as it usually is. While it took a couple of days to get both new Quattros installed, I did have a small battery charger connected and going during this time. The initial DC output was 10A or less after the system was configured and running. I don’t exactly remember the amperage, but it wasn’t large.

I’ve been through the MK3 to set one Quattro up as a Master and one up as a Slave and had zero issues doing so.

The Cerbo reads both units and appears to be doing what it’s supposed to do, though this is my first Victron system, so I don’t know what I don’t know.

The firmware is up to date on the Quattros as of today (they already had the latest).

I can’t get the Cerbo to update, but it has version 2.91 so it’s not that old. I get the Cerbo on my wifi, but every time I tell it to “check for updates” I get an “Error during checking” message. I cannot get to the Cerbo from VRM, so it’s a wifi/network issue someplace.

To be honest, I’m not that concerned about that. I’ll get the Cerbo updated when I get to a location with much better wifi abilities.

My real issue that has just quit after 4 days of doing it is the Slave Quattro has been pulsing the charger for a split second every split second. This physically buzzes the Quattro chassis, which is audible from inside the motorhome. Very annoying, to say the least.

It did finally quit for a short period, though comes back. Apparently the Slave acts as the finish charger, pulsing the charge to fully top off the batteries.

Because I’m using agm’s and everything is very simple, I did not make many changes to the original setup. I left everything alone other than creating the Master/Slave relationship. There is a generator, but I haven’t tried it yet. There is no solar, so no issue there.

Is there a setting I’ve missed that would stop the pulsing of the Slave or do I need to rubber mount it to stop the buzzing?

Thank you for your help.

2

You have to update the firmware. It is the first step in programming in comissioning. FYI 2.9 is hecking old.
{Both the inverters and the GX}

Side load it if you need to instructions here.

3

You need to test the system under load and see the current sharing.
As an FYI parallel set ups take a bit of knowledge and finessing. And wiring balance is the key.

4

I updated all software to the latest version(s). As I previously stated the Quattros were already running the latest versions.

The Cerbo now has the latest version. I now get several new error messages and the slave still pulses the charger every second or so. It also trips the circuit breaker for the slave inverter shortly after start up.

The system does not like to be running when I start the diesel engine, as I get over voltage warnings from the Cerbo. I’m assuming there is a setting for that, but I have not found it.

The system also does not like to have the shore power turned off. I have to currently turn off and restart the system to get the inverters to take over. That also has to be a setting I’m not seeing someplace.

It also does not seem to like getting shore power turned on. It seems like neither inverter goes into “pass-through”, so they are regulating the incoming AC power when it really doesn’t need to be regulated in my set up. The RV already has a power shedding system built in from the factory. The pass-through setting must be there, but again I’m not finding it. I did find what seemed to be an AC current limit but reducing it on the Cerbo does not stick. If I go back to that setting after a little while, it’s back to the 120 setting.

After rebooting the system several times, turning the Quattros off and on, running the slave only on charger for a bit then back to fully on, I am not tripping the slave circuit breaker anymore.

I’ve been working with parallel inverter systems now for almost 20 years, so I think I have a good handle on them.

I have never had a Victron system, so their software is still mostly a mystery to me. It is involved, to say the least.

The previous system was a working 2 inverter system, as was the system before that one, as well as the RV before it. I expect all of my issues are simply my inexperience with the software and the programming.

The physical install was very straightforward, simply moving stuff from the old inverter(s) to the new inverter(s). The only change was running an 8-wire network cable instead of the 6-wire the old system used. Everything else was exactly the same. That’s why I say it’s all in my lack of knowledge about the software, nothing more.

Further complicating things is some conflicting info in the various manuals. The Quattro manual seems to indicate any programming needs to be done with nothing else connected (only the slave, no Cerbo). The Cerbo manual seems to indicate do the programming through the Cerbo. Which is correct? Are they both correct? Can you do all programming through the Cerbo?

My real question and issue is how to get the slave charger to stop pulsing every second. I don’t think it should be doing that, but I can’t find any setting that seems to relate to that occurring.

5

Success, finally. Meaning finally I got smart enough to rethink the entire system and understand how it needed to be set up and initially programmed. Reading the links several times over helped. :wink: I’d read them prior to initially starting, but didn’t fully grasp what they were trying to tell me.

I’ll have to get further into the details and tweak things, but it’s currently quiet and functioning as it should have been all along.

Thank you LX for your help!

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6

Is there any reason to reduce the allowable voltage spread? I’m wondering if reducing the spread it would help protect the electronics in the motorhome. Currently the spread is 180V low to 270V high. Should it be narrowed to something close to 200V low and 260V high?

Or would I be better to turn on the Power Assist and let the shore voltage do as it will and have the Quattro(s) make up any differences?

I do have a huge battery bank, so I should be fine there. (Ten 210AH at 20hr agms) Also, there is a surge guard transfer switch already in the system which has similar voltage limits to the stock Quattro(s).