What to do if Endress+Hauser Proline Prosonic Flow 91 Measuring Instruments have no display and output signals?
- DdustinevansAug 4, 2025
If there is no display and no output signals from your Endress+Hauser Measuring Instruments, first check the supply voltage at Terminal 1 and 2. Then, inspect the device fuse. For 85 to 250 V AC, it should be a 1 A slow-blow / 250 V fuse. For 20 to 28 V AC and 11 to 40 V DC, it should be a 1.6 A slow-blow / 250 V fuse. If these steps don't resolve the issue, the electronics may be defective, and you may need to order a spare part.