Control Contactor With CERBOGX by Node-Red

Hi everyone, I have a system with two MULTIPLUS II 5000VA in parallel. I would like to control a contactor via the cerbogx using NODE-RED.

What I would like to do is this: when the battery reaches 24% the contactor closes giving the inverter the shore current. Could you give me some help?

Hi @FABIO57400
Multiplus has an ACIN contactor which can be set up with Assistants. Adding in switching with the 24% SOC logic is quite simple.
So no GX/NodeRed really necessary. If you have special needs though, please say…

hi, thanks for your reply. my need is to connect the manager only when there is 24% in order to bypass when the battery reaches 20%. In this way I avoid as much as possible the presence of the shore that could have overvoltages

I’m not sure what you mean. But That ACIN relay is also used to protect against grid overvoltage. It will open if not within spec anyway, and there’s even some adjustments you can make to the limits within the Multis.

I think it’s better to ask the question this way: I would like to control a relay port of the cerbogx when a certain SOC is reached. For example at 24% SOC close the relay

The best approach would be to setup your shore power as a “Generator” AC supply then user the generator start/stop functionality of the Cerbo relay.

You can then start the “Generator” on a number of different conditions including SoC.

You then connect the Cerbo relay to your contactor to start/stop the shore power.

It can also be done without an external contactor. You can control the internal AC In relay on the Multiplus via an assistant on the MP (requires Ve Configure to setup).

Hello,
The Answer of this question is yes, you can control the Cerbo Relay with a SOC condition…

This is an example with my red node system and one Multiplus + Cerbo…
As a starting point …

Xavier

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it’s exactly what i mean to do. i have to adapt this flow for my system that have 2 multiplus ii 5000va in parallel.
thanks so much

Welcome to Victron World and Happy to help…

Hi I’m still here writing xD I created the flowchart with NODERED and the cerbogx relay activates when the set conditions are met.
Now I can’t figure out how to wire the contactor, I bought a contactor with 220Volts coils but nothing happens when the relay closes, maybe I need a contactor with 24 volt coils?

CerboGX relay only rated up to 125VAC so you shouldn’t be switching 220V with it.

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OK , you need to plug a 220V phase cable to the Com pin of the relay and one other cable from the NO pin to pin 1 of the 220V the relay’s coil. The pin 2 of relay’s coil need to be connected with the Netral cable of the 220V…

on the picture Red cable = L1 or Phase, Black cable = Neutral

image

image

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Check this FAQ about using the GX relays to drive contactors, there were many cases of fused relays on the old forum.

https://community.victronenergy.com/t/using-inverter-mppt-gx-device-programmable-relays-with-higher-current-inductive-or-capacitive-loads/99

In fact, with DC, and, other point is to, preferably; use DC to handle the relay.
Meaning :
image

The switch represent the Cerbo internal Relay used inDC mode.
And the load could be whatever according to Relay caracteristics…

ok but since the 220 Volts will power a coil of a contactor, the absorption, in terms of amps will be minimal so I deduce that there would be no problems in passing the 220 Volts through the COM

In fact there is no problem.
This is only in the way to prevent having 220V too close of the cerbo in case of trouble or if you need to manipulate it like adding / removing wire of accessories…