Control a fan with Cerbo GX temperature monitoring

DIY
, , , ,
1

Id like to control the temperature of the technical “room” of my van (containing Orion, Multiplus, Smart MPPT and more) with two small fans, controlled by the temperature monitoring of the Cerbo GX. Can I use the standard temperature probe of Victron and how should I connect the fans ? Is the Cerbo providing the power to the fans ? Could someone share a wiring diagram ? Thanks in advance

2

You need to use the temperature probe type " Temperature sensor Quattro, MultiPlus and GX Device" model number ASS000001000

GX temperature sensor

The relays on a Cerbo GX are just switches, they have no power so you need to provide power. Go from power supply/ battery positive to relay COM, from relay NO to fan positive, from fan negative to power supply/ battery negative. Most low power fans running on 12V should be OK from the relays 6A rating at 12V BUT if you have lots of fans or powerful fans take note of this link

3

Thanks a lot, very clear answer. I plan to use two small fans (https://www.amazon.com.be/dp/B0DFXYMYSL/?coliid=INMZ9FZPKXY20&colid=2TPCYF59NUIEL&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it_im)
1.8W each, 0.18Amp (12VDC)
Should be OK to connect them in parallel, right ?

4

You should be OK to connect those in parallel. They should (not guaranteed) be OK to.power from the relay direct, a start up surge of 10 times normal current will be 3.6A so.in the relay limit.

5

Great - is the “10 x normal current” a general rule to apply broadly for the surge current ?

6

Just to be sure, I have already one similar temperature sensor connected from my Multiplus to the LiFePO4 battery - (PowerQween 300Ah) to monitor battery temperature (not sure this battery has self heating or any type of regulation through its internal BMS), so my question is if there is maybe a risk of kind of “confusing” the system by installing a second temperature probe on Cerbo GX for the fan control ? I would guess no but would like to be sure …

7

For a motor start up surge 6 times normal current is often used, 10 times is to be on the safe side.

There will be no confusion, when you add a temperature sensor to the GX you have to go into I/O settings to turn it on, then go into the devices menu to the new temperature sensor to set it up and give it a name. Then when you set up the relay temperature rules you can see which sensor to use. I have 6 temperature sensors and have no problems setting the right one to the relay function. Everything is in the manual.

8

Another question, can I control the two relays of the Cerbo with the same temperature sensor ? (idea would be to distribute more fans between the two relays in case I need more cooling power , to avoid approaching the limit of current at fan motor start-up (surge coming close to relay current limit) - thanks

9

Yes. Under temperature control rules, for one temperature sensor you can activate 2 different control rules and assign then to different relays.

10

Works perfectly, thanks

1 Like