natebert avatar image
natebert asked

Ve.Bus RJ45 cabling order

Is there a proper order for cabling the following Ve.Bus devices?
(Usually with a 'bus' order doesn't matter.)

DMC GX (required for current limiter when using a Ve.Bus BMS)
Ve.Bus BMS (required for Victron SmartLithium batteries)
Ve.Bus Mains Detector (to allow for DC start when AC is present)
Inverter/charger 1 (split phase)
Inverter/charger 2 (split phase)

In a full Ve.Bus chain of devices, the Ve.Bus BMS manual suggests that there is a preferred order (page 4):

This leads me to believe that there is a required Ve.Bus order of devices which with this equipment list would be:
DMC GX -> Ve.Bus BMS -> Mains Detector -> Quattro1(leader) -> Quattro2(follower) -> CCGX

Can Victron confirm this order requirement?

I guess this leads to a bunch of other related questions such as:

Do the specific ports on the Ve.Bus BMS have to be used as labelled?
Remote to DMC GX, and Ve.Bus to the Mains Detector, before the Inverter(s)?

Is there some unspoken addressing conflict if these are wired out-of-order?
Is it that the DMC is on the same address as the CCGX, where we are hiding the DMC behind the Remote port on the Ve.Bus BMS is required?

The DMC manual seems to suggest that you can connect it directly to an inverter which indicates its a Ve.Bus Device, but the Ve.Bus instructions indicate otherwise.


MultiPlus Quattro Inverter ChargerBMSCCGX Color ControlVE.BusDigital Multi Control
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1 Answer
ejrossouw avatar image
ejrossouw answered ·

Hi @natebert I am not sure I see the relevance of these questions given the Victron tested/ supported connections are quite clear. Why do it differently? Maybe I am missing something?

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natebert avatar image natebert commented ·

I thought it would be pretty self evident to use it like a bus architecture. In a communication bus, order usually doesn't matter, especially since its called a 'Victron Energy Bus'. Victron is often referred to as a greener company and using an optimized order would save on cabling lengh and materials. I'd like to be able to simply run the shortest route for each device vs having to pull cables to meet a specific order, which is then more of a point to point connection method.

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ejrossouw avatar image ejrossouw natebert commented ·

I can totally see the sense in that, however I think you will find that typically equipment would be located in close proximity like on boats, RV's, vans etc. with short cables from 0.3m onwards. The future however is becoming more wireless so that should save you some valuable cable and maybe the future may even bring data over power ... then probably not ;)

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natebert avatar image natebert ejrossouw commented ·

I could see in a confined space like a boat where leads could be kept short.
In our 41' RV, the GX devices (DMC and CCGX) are ~17' (cable length) away from the battery/inverter equipment. So reducing the number of long leads from CCGX (Ve.Bus, Ve.Can, Power, USB, relay) without having to run another RJ45 for the DMC, direct to the BMS, where a short jumper between the CCGX and DMC GX would be useful.

I wish the Cerbo was more readily available and its connections weren't so short.

It would still be good if someone like @Guy Stewart (Victron Community Manager) could chime in if the ve.bus bms and other devices do have the very specific order of connection as loosly described across the various bits of documentation. It seems that there is a very specific connection order and I'd prefer to get it right.

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