question

dfraizer avatar image
dfraizer asked

Temp sensors for Cerbo GX

I am looking to add temp sensors in my refrigerator & possibly a sensor reading supply air from my AC. What types of sensors do I need?

cerbo gx
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

9 Answers
Stefanie (Victron Energy Staff) avatar image
Stefanie (Victron Energy Staff) answered ·

Hi @DFraizer,

you'll need the temperature sensor for Quattro, MultiPlus and Venus GX, which is also good for the Cerbo GX. See: https://www.victronenergy.com/accessories/temperature%20sensor%20qua%20pmp%20venus%20gx?_ga=2.10551028.1933131784.1590438491-1969333987.1588075539

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

dfraizer avatar image
dfraizer answered ·

I appreciate the answer, but the temp sensor for the multiples does not seem appropriate for a refrigerator. Will a 2 wire sensor work?


1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

The sensor for the MultiPlus is exactly designed for such things. The big cable lug is electrically isolated as is the rest of the sensor.

0 Likes 0 ·
chad-poindexter avatar image
chad-poindexter answered ·

So can I use the temp sensor that came with my Multiplus 12/3000 and hook it to my Cerbo and simply expose the lug to the outdoors and get a reading from that?

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

permawatt avatar image
permawatt answered ·

hello

use LM335 TO-92 sensor.

permawatt

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

permawatt avatar image
permawatt answered ·

hello

inexact, le capteur d'un M+ est une sonde LM 335Z dont la plage d'utilisation habituelle est de

- 40/+120°C ... donc parfaitement utilisable pour un frigo.

2 fils = no adjust possibilities, 3 fils= adjust possibilities sonde-victron-lm335z-6804.jpglm-335-broches.png

benoit Permawatt


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

laurenceh avatar image
laurenceh answered ·

I made myself these.

See my post in this thread.

https://community.victronenergy.com/questions/63811/temperature-sensor-for-water.html?childToView=63865#comment-63865

These are attached to my Rpi 3B+ but they should work on a real GX device.

4 comments
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Rob Duthie avatar image Rob Duthie commented ·

Hi

Yes i use those on my raspi systems and they work perfectly. I fit them into a stainless steel tube enclosure, as per photo.

20210113-105653.jpg

0 Likes 0 ·
Nick Hardy avatar image Nick Hardy Rob Duthie commented ·

Looks good, Rob. Where did you find the stainless tubing?

Nick Hardy

0 Likes 0 ·
Rob Duthie avatar image Rob Duthie Nick Hardy commented ·

You an buy it anywhere on line, i do carry a stock of these tubes.

Regards

Rob D

NZ

0 Likes 0 ·
cpt-pat avatar image
cpt-pat answered ·
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

raymiller avatar image
raymiller answered ·

One problem with the LM335Z is the absolute accuracy, from the specification data sheet the uncalibrated figure is 6C max. Not the most useful these days, you could be lucky but my experience with my sensors I've been closer to the max. I needed to add the calibrating circuit on the adjust pin and calibrate to +/- 0.5C from a known reference. Works well, the down side is extra components and where to mount. The adjust circuit is found in the LM335 Ti specification data sheet.

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Kevin Windrem avatar image Kevin Windrem commented ·

I would mount the calibration potentiometer right at the 335 and enclose the entire assembly in heat shrink tubing. They make heat shrink tubing with a sealant inside that would waterproof the circuitry inside. I've even done this with a long pieces of regular heat shrink and pinch the sensor end while still hot to seal it. The tubing is long enough to take the other end to an area that doesn't need to be waterproof.

To make a smaller temperature probe, you could calibrate the 335 then remove the potentiometer and replace with fixed resistor values.

There is also a way to calibrate the sensor in the GX device.

0 Likes 0 ·
aaxc avatar image
aaxc answered ·

I can highly recommend RuuviTag bluetooth sensors. I have 12 of them in my house and some of them also connected to my Cerbo GX in parallel. RuuviTags can also been placed inside a fridge. Just make sure they are in range of the Cerbo.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.