question

jeromed avatar image
jeromed asked

Node red : Multiplus II primary relay

Dear all,

My installation consists of solar panels, Pylontech batteries, a Multiplus II, and a Solar Charger MPPT 450/100. This set is controlled by a CERBO GX. I have installed Venus Large and Node-RED.

I already control a hot water tank from a CERBO GX relay programmed with Node-RED.

I would also like to program the primary relay of the Multiplus II via Node-RED. I can do this with the Relay Assistant but cannot find it with Node-RED. Do you have an idea?

Jérôme

Multiplus-IIRelayNode-RED
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3 Answers
liam-hogan avatar image
liam-hogan answered ·

Hi @JeromeD

Controlling the relays in the Multiplus (including AC relays and AUX relay) are currently not possible through Node-RED unfortunately.

It is my understanding that this is due to a firmware limitation in the Multiplus units themselves, so adding the feature would mean updating the firmware on every Multiplus which is not something the team is planning on doing right now.

This has been mentioned a few times on the forum and also on the Victron Node-RED github like here: https://github.com/victronenergy/node-red-contrib-victron/issues/99

You could use the second relay in the Cerbo if you need to switch something else.

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jeromed avatar image
jeromed answered ·

Hi @Liam Hogan ,

Thank you very much for this clear and detailed answer. :) It will save me time searching for the relay in the Node-RED interface.

Nevertheless what a pity to be limited to the 2 relays of the CERBO GX.

Node-RED interest, is precisely to be able to control loads in a smart way (hot water tank, EV charging, pump, standby...). 2 relays only, it's not that much :o(.

I hope that updates will allow to remedy it soon.

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liam-hogan avatar image liam-hogan commented ·
This sort of thing is indeed one of the reasons for implementing the Node-RED system on Venus. But it just so happens in this case that it's a limitation built into the physical Multiplus devices and is not something that is easily fixed or made available in software.


If you require more relays to control than the two in the Cerbo, there are other ways to do this (albeit requiring a bit of technical know-how) like using a USB relay board or one that is controllable over the network using MODBUS, MQTT, websockets etc. You could then integrate control for those into Node-RED.

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apple047 avatar image apple047 commented ·

I take it the MPPT relay can't be controlled in node-red either. (250-60TR)

I was trying to wire a fan when the output is >85% for assisted cooling, I've tried all options available with no state changes on the relay.

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Dirk-Jan Faber avatar image Dirk-Jan Faber apple047 commented ·

It is possible on the MPPT. Make sure that the relay is set to manual mode (which can be done with VictronConnect).

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apple047 avatar image apple047 Dirk-Jan Faber commented ·

i suspected this must be the case but can’t see such setting available, what am I missing?

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Dirk-Jan Faber avatar image Dirk-Jan Faber apple047 commented ·

You are right. The documentation also says that it is not possible yet (https://www.victronenergy.com/live/venus-os:large#solarcharger_mppt_relay).
I thought it had already been added, but was wrong about that.

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wkirby avatar image wkirby ♦♦ commented ·
If you need extra relays that are for swtching AC powered devices the you could use IP smart plugs and address them directly from a Node-RED.

I use the TP Link Kasa ones, there are nodes available for the smart plugs and smart bulbs to address them directly from Node-RED, no need for internet or any cloud nonsense.

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wdh2550 avatar image
wdh2550 answered ·

The CerboGX relays can be operated by the "Relay Control" node. See attached
relayflow.txt


relayflow.txt (4.4 KiB)
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