It would be great if there was an option on the Multiplus controls via the Cerbo GX and VRM to manually ignore the AC input. It would be useful when you need to use a load at the AC frequency set on the inverter, and not at the AC input frequency. When this is necessary, having to physically disconnect the AC input can be difficult and it can be much more practical to do it via the GX Touch. It is possible to have this functionality using a Cerbo relay and a Multiplus AUX input, programming an assistant on the Multiplus to ignore the input depending on the state of the AUX input. But having to make this electrical connection, taking up a Cerbo relay and a Multiplus AUX input just to make a communication that could be made by the existing communication connection between the Cerbo and the Multiplus is a rather stupid way of adding this functionality.
I do it with node red, no hardware required.
@MiPaul can you give the node red string how it look like
This is what I have. There is a little delay when setting back to shore power.
[
{
"id": "9ee0cefc4599106f",
"type": "victron-output-vebus",
"z": "4d463eef0b6d8244",
"service": "com.victronenergy.vebus/276",
"path": "/Mode",
"serviceObj": {
"service": "com.victronenergy.vebus/276",
"name": "Inverter"
},
"pathObj": {
"path": "/Mode",
"type": "enum",
"name": "Switch Position",
"enum": {
"1": "Charger Only",
"2": "Inverter Only",
"3": "On",
"4": "Off"
},
"mode": "both"
},
"name": "",
"onlyChanges": false,
"x": 570,
"y": 2120,
"wires": []
},
{
"id": "348698a073c8845f",
"type": "inject",
"z": "4d463eef0b6d8244",
"name": "Inverter Only",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "2",
"payloadType": "num",
"x": 270,
"y": 2080,
"wires": [
[
"9ee0cefc4599106f"
]
]
},
{
"id": "729639e9e3f501af",
"type": "inject",
"z": "4d463eef0b6d8244",
"name": "ON",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "3",
"payloadType": "num",
"x": 250,
"y": 2140,
"wires": [
[
"9ee0cefc4599106f"
]
]
}
]
Good to know, if I ever need to free the Cerbo relay or the Multiplus AUX input I will research this Node red, which I happened to hear about for the first time yesterday. In any case it would be great to have this option directly through Cerbo/VRM so we don’t have to study yet another feature and learn how to program it, which doesn’t seem trivial.
No, because in inverter-only mode it synchronizes the inverter frequency with the AC input frequency, instead of using the frequency configured for the inverter. But your question made me think that this would be another solution, even better and more practical: ignore the AC input when in inverter-only mode. In fact, I don’t know why it isn’t already like this, it almost seems like a bug.
Agreed! I am installing a system on a boat where the boat is all 50Hz and the incoming power is 60Hz. I would like the Multis to ignore AC input/frequency when it senses 60Hz. We only have this issue when at the dock. The genset is 50Hz and we plan to go to Europe. This could be a very simple change in programming at Victron.
I’m currently looking at a Frequency driven relay to open a contactor that feeds the Multis when 60Hz is sensed.
To automatically reject the AC input on another frequency is easy, there is an option in the Multiplus settings for this (see the attached image of VE Configure), you don’t need to add any other equipment. What is not there is a simple and direct way to manually ignore the AC input, when necessary. I want to have the AC input connected most of the time, to charge the battery, and I want to be able to turn off the AC input only when I need to use an appliance that does not work with the incorrect frequency (the microwave oven).
Understood. I think we are both looking for the same thing. I’ve decided to use a frequency monitoring relay in conjunction with a contactor. When the vessel senses 60Hz coming in, it will disconnect the power supplied to the Multis. At that point, they should go to invert @ 50Hz.
The main issue is that when you uncheck the “accept wide range…” box, the inverter may disconnect itself from the 60Hz supply, but it still senses 60Hz and it only outputs 60Hz. Only when it can’t sense 60Hz does it switch over to 50Hz.
That is does that sounds odd to me to.
But usually the conclusion, after checking things like these with the responsible dev team, the conclusion is that there are good reasons for things to are as they are.
I’ve listed this to discuss and check. Might take a while: the list is long and I’m always balancing questions vs. focus and development.
Thanks, Matthijs / Victron.
No. In this case, it completely ignores the AC input and the output is at the frequency set for the inverter. What you are talking about happens when you configure it for inverter mode only. In this case, yes, it just does not charge the battery, but it does not ignore the AC input and synchronizes the inverter with the input voltage.