Signal Issues in Process Control Equipment
Ground loops and non-isolated commons can be a nuisance for both industrial process control equipment installers and maintenance personnel, but they can be easily avoided by good planning and installing practices. These two signal connection problems can lead to unpredictable, incorrect, out of range or averaged process signals and, in rare cases, damage to devices. Problems can be avoided by following standard installation best practices that can reduce or potentially eliminate signal issues”.
(Precision Digital Corp., ‘The Current Quandary’, August 2017).
A common issue after liquid level sensor installations is damaging spikes or inaccurate 4-20mA signals from the sensor that is caused by improper grounding. This article from Precision Digital discusses causes, troubleshooting and best practices for preventive maintenance:
Ground Loops & Non-Isolated Commons | Precision Digital
Other Electrical Considerations
When using Madison level switches, it is important to consider the applications electrical parameters. Our level switches utilize reed switch technology, which are glass encapsulated, magnetically actuated switches. Madison generally provides electrical ratings for resistive loads; however, where the maximum current of the load permits, the switches are capable of controlling devices such as motors, solenoids or coils that produce capacitive or inductive electrical loads. Where possible, Madison recommends the use of general-purpose/isolation relays or controllers to protect the switch.