I am running a VM148 on a solar system to run a freezer at fridge temperatures. The setting is 0 - 8 degrees C. The displayed temperature keeps on jumping up to 3 degrees, up or down. Could it be that the temperature sensor is defective?
Further information:
- In the setting mode the A and B temperatures are displayed stable. The calibration temperature is displayed unstable, jumping at the same rate as the fridge temperatures.
- An earlier, different jump problem has already been solved satisfactory. The display used to jump whenever an inductive load like a pump or similar devices were switched on in the same solar system setup. This problem has been solved by installing a galvanic isolation module in the panel’s 12 V power supply wire.
The current problem must therefore have other possible causes. I would be grateful for your suggestions. If the sensor is the culprit and must be replaced, what are the specifications of the part?