Hello colleagues! In many of our systems, I connect the temperature sensors that come with the inverters to the GX devices (Victron Part Number ASS000001000: Temperature sensor Quattro, MultiPlus and GX Device). The batteries that we install have a built-in temperature sensor, so we use these "extra" sensors to measure the temperature of the environment, water heaters and so on. We already have quite a few of these sensors, and they all work very well. Here is an example:
In one of the new systems with Cerbo GX, I noticed that the displayed temperature is about 10-11°C higher than the actual one. At first I thought that I got a defective sensor, so I connected two more of the same sensors (from other lots) to this Cerbo, but they all showed approximately the same wrong temperature.
P. S. I know that the type C temperature sensor that comes with RS products (Victron Part Number ASS000020000) is not compatible with GX devices.
Then I connected one of these sensors to the Quattro inverter, and it immediately showed the correct temperature:
It looks like there is some problem with this Cerbo GX. Interestingly, the serial number of this Cerbo GX falls within the "HQ2201xxxxx up and including HQ2220xxxx" range, for which Victron officially announced a problem with the power supply and recommends installing a capacitor on the power terminals. Here is an excerpt from a letter from Victron about this "What started the issue is a recent design change. The change was needed to overcome a sudden semiconductor failure and ensure a stable supply of Cerbo GX-es. But unfortunately we made a mistake in that re-design."
Is it possible that this Cerbo GX is supplying a slightly incorrect reference voltage to the temperature sensor? How can this be fixed?
