I connect 3 temperature sensors to the cerbo gx to control a fan to cool my mppts.
If one of the sensors detect > 50° then fan = ON
If all sensors < 40° then fan = OFF
Manual Page 58:
In GX products where two relays are available (Cerbo GX & Cerbo-S GX, Ekrano GX), it is possible to have a single temperature
sensor control both relays. It is also possible to have a single relay controlled by multiple different temperature sensors......
How can I do that ? Example ?
Thanks for your help
Wolfgang
What temperature sensors are you using?
There are a number of ways you could do this. If you are using the Victron temperature sensors then a lot of the hard work is done for you... basically if any of your sensors are over 50° you want to close a relay contact, to switch a fan (AC/DC? , what current?) until the temperature reduces to 40°? ie Activate at 50 and De-activate at 40..
Connect your 3 sensors to the Cerbo and make sure you are "seeing" them in your device list.
Assuming that you use the NO (normally open contact on the relay, since this is more efficient), to switch an earth to the fan? Just be aware of the voltage/current limits that you are switching.
https://www.victronenergy.com/live/venus-os:start#comparison_table
Consider also some protection diodes to prevent any inductive flyback, and/or reverse polarity from fan or external relay switch??
I have just checked on my system where I have relay 2 controlled by temperature from one sensor and found that it can be programmed to work from all of your temperature sensors in the temperature rules page. See example where it is configured to switch on 2 of my 5 sensors.
I use the 'Temperatursensor for Quattro-, MultiPlus- and GX-Device' direcly connected to temperatur input of the GX- the connecton of relay and fan is no problem - I am electrican...
Configuration:
Temperatur is shown:
Condition ?? - What means Bedingung (Condition) 1 and 2 ???
Can you show me your relay settings
and rules for temperatur settings for relay
I do not understand the 'LOGIC' of that system...
Thank you
Wolfgang
On my central heating system I have a motorised valve that opens to heat the hot water tank once the heating water is above 55degC and closes when the heating water is below 50degC. It is a bit like your fans on at high temperature, off at lower. Here are my screenshots. When taken the water was 20degC so the condition is "Inactive".
The Condition (1 or 2) is just the logical requirements for performing your required switch.
eg Condition 1 - Turn on at 50°, turn off at 40°. This will be "inactive" if the condition is NOT met.
It is possible to have another condition (Condition 2) with another set of limits for the same temperature sensor (I don't think you need that for your requirement). You need to set-up the same Condition for each sensor, but for the same relay??
