A few months ago I purchased an RV. The RV is equipped with what I have come to understand is a relatively complex Victron solar system.
I have been learning about the system and have started generating a wiring diagram.
My question today has to do with the VRM Portal. I can understand most of the information displayed, but it doesn’t seem to match the installed components. Below is a screenshot of the display.
Based on what I understand, the screen tells me the following: there are 0W produced by the PV array (it is nighttime), the DC consumption in the RV is 174W, the batteries are at 100% SOC, the grid is providing 1459W of AC power, the RV is consuming 1236W of AC power
Question 1: Is my understanding correct?
Question 2: What are the two devices circled in red and green. I think they are the two Multiplus inverter/chargers, but I’m not sure.
The following is as far as I have been able to get to with the wiring diagram. The wires are not easily accessible for tracing. This system doesn’t use a Cerbo GX. It used a Raspberry Pi.
Looks like you may have 2 Multiplus inverters operating in parallel or as part of a split phase system. These will both be shown as the device circled in Red.
The device circled in Green is the MPPT solar charger. This should also charge the main house bank. The other Voltage regulator drawn in would regulate the charge from the vehicle engine, also to the main bank.
The device you label as an auto-transformer should perhaps be an isolating transformer….??
My system does have 2 Multiplus Inverter/Chargers. Based on what the previous owner told me, 1 Inverter is connected to L1 coming from the grid, and the 2nd inverter is connected to L2 coming from the grid. I believe this is called a split phase system?
If there are two inverters, shouldn’t they both show up on the VRM portal?
This system is installed in a 5th wheel RV. It doesn’t have its own engine. I have not been able to determine yet what the black and yellow wires from the Voltage Regulator, are connected to. My understanding is that it reduces the higher voltage coming from the solar panels into a lower voltage that the system can use. I would guess that the output from the Voltage Regulator would have to get to the batteries somehow.
Regarding the wiring diagram (see below), the connections shown for the components circled in green are confirmed. I have not been able to determine the connections for the components circled in black. The junction box circled in red is a mystery at the moment. I will open it up today and see if I can make any sense of what I find inside.
I am also not sure of the direction of current flow among all of the components. I read that some of the components work both ways, depending on the presence of power from the grid, presence of a generator or lack of any external power in which case the RV will be powered from the batteries. I will have to do some more learning.
The system is working fine. I just want to understand it so that if it stops working, I have a better idea of what questions to ask.
Red are the inverters (VE.bus system, can be one inverter or a couple working together, in your example two in splitphase config. But for the system they are one thing)
Green is the MPPT, solar charger
Not necessary, the MPPT does that on its own without the need for further voltage regulators.
I rather think this regulator takes 12V power from the tow vehicle to supply 24V while towing.
Concerning the 24V, your batteries are wired wrong in the schematic (since the MPs are labeled 24V in the schematic i guess the system is 24V). They should be wired two in series, then those packs in parallel
Concerning the 24V, your batteries are wired wrong in the schematic (since the MPs are labeled 24V in the schematic i guess the system is 24V). They should be wired two in series, then those packs in parallel
I have full access to the batteries and the schematic is correct. The batteries are wired exactly as shown in the schematic. Each battery is 25.6V & 200AH The way they are wired now, in parallel, they produce 25.6V & 800AH.
I rather think this regulator takes 12V power from the tow vehicle to supply 24V while towing.
The regulator converts 24V/36V to 48V. It could get a max of only 12V from the tow vehicle.
Updated schematic. I still haven’t been able to see where the output from the voltage regulator goes, but after looking in the large junction box, I found that L1 goes to Inverter 1 and L2 goes to inverter 2. I still have to find out where L1 out and L2 out go after the junction box.
The voltage regulator, which turned out to be a Step-Up DC to DC Converter (24VDC to 48VDC), feeds 48VDC to a PoE injector, which in turn provides power to the Starlink dish via a custom Ethernet cable.
It’s taking a while, but I’m getting there. Thank you all for your help.
One item remains and I’m not sure where it goes, the DC-DC converter circled in blue in the lower left corner of the schematic. I believe that it supplies the 12VDC side of the breaker panel, but I can’t trace the wires to see where they go.
Can anyone offer ideas of how this may be connected to the system? There are 3 cables attached to it. See pictures below.
My best guess is that the positive 18-32V input & the negative cable, come from the Lynx Distributor and the positive 10-15V output goes to the 12VDC side of the breaker panel, but I’m not sure. Shouldn’t there be a negative cable going to the 12VDC side of the breaker panel as well? Where would it come from?
