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sintesis avatar image

Venus GX temperature inputs

There are two temperature inputs on the Venus GX, but there is not much information about them in the manual. Are these only for the Victron battery temperature probes or can I connect another temperature sensor to them, like for monitoring for example room temperature, and if so, what kind of sensors will work (types like PT100, PT 1000 etc.)?

Venus GX - VGXTemperature Sensor
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Hi, I am looking for the same Information: I want to add Temperatur sensors to the venus gx. The best would be a pt100 sensor. I only want to log the Information. I have read the comments from Victron - use separate Temperatur Regulators..... But I can see the Venus GX Information online and therefore the easiest way to get more Information is to use this platform and all inputs.

I haven't continued to investigate this issue, but the case is that on my Device List I have two temperature sensors that are called "Generic Temperature Inputs" but there is no information on what kind of sensors that can be connected and how to connect them. Is there any documentation on this?

According to the Venus GX datasheet the part number that can connected is called ASS000001000. But that does not sound as a Generic Temperature Input as that part has to be fixed ON something, while most common temperature sensors are probes that are put IN something (water tank, water flow, air flow, etc.). Is this only part that will work for this "generic" input?

6 Answers
sean avatar image
sean answered ·

The GX temp probes are simply encapsulated LM35X 's.

As per the circuit diagram.

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dr-gerhard-baier avatar image
dr-gerhard-baier answered ·

Hello and thanks for the Information. I had a look at the wiring diagramms and I got the Information about the temperature sensor LM335. Now my question:

The wirering diagramm and the VenusGX Manual Show two Pins for interfacing one sensor:

GND and OUTPUT.

The LM355 has three pins: GND, PWR and OUTPUT.

Is there an Information available how to connect the LM355 to the VenusGX?

Many thanks

Gerhard Baier

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Just Gnd and output are required at the GX - Venus reports them as "generic"

@Dr. Gerhard Baier
The LM335 has three pins: GND, ADJUST and OUTPUT. The ADJUST pin can be left unconnected if you are satisfied with the accuracy of the sensor. Datasheet:
http://www.ti.com/lit/ds/symlink/lm135.pdf

Great, thx a lot for completing the available information on these inputs. Now I can get two LM35X's (or LM335) and embed them so they can used more generically in liquid or in a tube. Now it would be great to have the same added information for the three TANK inputs!

The tank sensors are well documented in the setup of the venus gx. You can either choose 0-180 ohm or 230-30 ohm full scale. And "normal"(that one I don't get).

https://www.nuovarade.com/product.php?productId=6150&categoryId=224 is for instance a very suitable sensor if your tank is not over 60 cm deep.

sintesis avatar image
sintesis answered ·

Hello Guy, thanks for the comments.

This a 48V system with not that many panels but quite generous battery storage, for a small off-grid rural house in an olive grove that isn't used as a residence, but for frequent shorter visits, when it will be used intensively. There is also a wood stove with a heat-exchanger connected to the water tank for when there is not enough sun in winter.

The concept is to create a three-step energy storage solution:

  1. From the solar panels into the batteries
  2. Dumpload of surplus energy into a generous hot water tank
  3. Impulsed into the heavy concrete slab as underfloor heating

The hot water will never used directly, neither for underfloor heating, nor for hot tap water, but is always mixed by a thermostat first to more normal temperatures.

And as you said, the temperature regulation should best be done internally by the water tank control equipment.

So the functionality that I would need from Victron is perhaps already in place, and will be even better with node-RED.

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sintesis avatar image
sintesis answered ·

Thank you for the answers.

What I am trying to do is to set up a chain of logic to use surplus solar power to store it as hot water following:

  • The batteries are almost full (95–99%) (figured that one out as an output relay on the battery monitor)
  • The water is not too hot already (below 90 degrees Celsius) (that is why I got interested in the temperature inputs que already have on the Venus GX)
  • The sun is up (9 am to 3 pm for example) (external clock needed, I presume)

So if you are developing a function that would include all of this functionality in one package that would be great!!

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In my opinion hot water temperature regulation is best done by the dedicated and specifically designed thermostat contactor that is included in most electric hot water units.

90 degree water is VERY hot, and very likely boiling point already at the point of the heating element.

I think about 60 degrees is usually necessary for bacterial disinfection and 50 degrees is scalding point, hot enough to be dangerous and burn people.

The rest of the project has merit for sure, tho not straight forward out of the box, is possible with available tools and documentation.



markau avatar image
markau answered ·

Can the temperature input to the Venus GX be used to drive one of the relays? For example if the temperature reached 24 degrees close a contact to turn a fan on?

Thanks Mark

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A solution for all your particular ‘I want to switch this when such and so’-wishes is being worked on though!


See here:


https://community.victronenergy.com/questions/549/feature-request-scheduled-virtual-switch-for-venus.html

Don't think you can do it in the Venus. It is possible to do it with some remote logic via Modbus Tcp.

mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi, they are specific to our probes. We don’t support others.


Or, determine the circuit from the schematics; here: https://github.com/victronenergy/venusgx-hardware


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Thanks @mvader, a pity though as the Venus GX is a great hub for remote monitoring. Anybody else in the community managed to "hack" these temp inputs ... ?

Why not use our probes? They don’t need to be used to measure battery temperature. You can put them on everything (wired)

laurent avatar image laurent mvader (Victron Energy) ♦♦ ·

Hi,

Can somebody provide victron temperature sensor reference for that kind of use ?

Regards,

You can see the sensor type in the schematic that mvader linked to above.

Is this the part described on your product site as "Temperature sensor for BMV-702"?

No, that is for the BMV and it will not work.

The correct probe for the VENUS is

Victron Temperature sensor QUA/PMP/Venus GX - order Victron part number ASS000001000


manowell avatar image manowell Guy Stewart (Victron Community Manager) ♦♦ ·

I search for this product on your website and only see references to other spec sheets and documents. I can see it on your price list in euros.


Amazon doesn't know about it, doing a google search for it show one seller (PKYS) and one on eBay in the US.


Is it that rare of a part in North American?

Thanks,

Amazon is definitly not a qualified Victron Distributer. You may should think about to contact an official dealer for that.

Have you tried to find a local dealer to you? The "Where-to-buy" tool should offer some guidance. You can even select your state to find local dealers: https://www.victronenergy.com/where-to-buy

The part comes supplied with every Multiplus out of the box, so it is not rare.

It was an oversight that it is not on the Victron website, I have notified that team and they will update it and make it clear shortly. Thanks for reporting this.