AC Voltage Mitigation

Problem:
When pipelines are in a common corridor with energized power lines, electric and magnetic fields can cause unwanted voltage to appear on the pipeline. This induced voltage requires low resistance grounding for mitigation, while cathodic protection demands complete isolation for the pipeline.

Solution:
DEI products provide continuous AC grounding for pipelines with induced voltage, while leaving the cathodic protection voltage unaffected. The device presents low impedance to alternating current and high impedance to direct current, and connects between the pipeline and a grounding system.
 

Mitigation designs for induced AC voltage are best done by specialists trained in the proper analysis techniques. Such analysis involves measurements and electrical modeling, using software developed for this task. While an overview of the issues involved is shown below, complete analysis may involve the use of such specialists.

Small projects can have reasonable estimates applied to determine product ratings and a basic system design. Examine the issues outlined below or call DEI for additional guidance.

To implement an induced AC voltage mitigation system, the following issues
need to be addressed.
1. A suitable low resistance grounding system is needed
2. The Measuring Induced AC Voltage and Current flowing to ground needs to be known
3. Determining AC Fault Current exposure exists and should be estimated
4. Is this site considered a Hazardous Locations Definition?
5. Mounting the DEI device for above-grade or underground connections

See Application Note 6 for a full review of this application, including mitigation considerations.