There are several causes of ground loops in any instrumentation installation. Some of them are itemized below:
Differences in potential between the points of the ground plane to which the ground terminals have
been connected.
Causes of Ground Loops
- Inductive coupling
- Capacitive coupling
- Use of internally grounded instruments inside an already grounded loop
- Cable shields grounded at both ends
- Grounded thermocouples with non-isolated transducers
- Four wire transmitters used as input to a receiver instrument grounded to a different ground connection