Decoupling Devices Reduce Stray Currents
A solid-state decoupler performs two essential functions in the energy industry. It isolates DC current and grounds AC current. Decoupling devices are a cost-efficient, certified fail-safe solution and are used with cathodically protected pipelines, tanks, and other grounding systems.
A decoupling device prevents galvanic corrosion of a pipeline or metallic structure. Normally these function by applying a low voltage DC bias to the structure, isolating DC current flow to equipment or grounding materials. But the other functions that decoupling devices provide are safety grounding protection from AC faults and lightning.
Overall, to ensure a safe working environment, a solid-state decoupler protects against high voltage of insulating joints, isolates DC currents, and grounds AC currents of cathodically protected structures.
How to Use a Solid-State Decoupler
Solid-state decoupling devices have various applications and uses. One practical use is in the energy industry with oil and gas pipelines. When protecting a pipeline or metal structure from galvanic corrosion you will need a cathodic protection system, like a cathodic protection rectifier, in place of worker safety.
If you want to know how to use a solid-state decoupling device, consider its most common use with buried pipelines. With a buried pipeline, laying a zinc or copper mitigation wire and connecting it electrically to the pipeline will safely channel induced AC to the ground.
However, because the mitigation wire is connected to the pipeline electrically, the cathodic protection system in place has to protect both the pipe and the mitigation wire. The wire requires more current protection and could result in less cathodic protection for the pipeline.
When using a solid-state decoupling device between the pipeline and the mitigation wire, the operations are isolated. The cathodic protection system will now be able to work normally, safely grounding and mitigating induced AC current and protecting workers in the surrounding area.
Solid-State Decoupler Features and Benefits
Maintaining an off-state desired range of voltage between pipe and ground gets rid of stray currents, or the imbalances or wiring flaws in electricity flow via buildings. This is what the solid-state decoupler is best known for.
The basic functions of a solid-state decoupler:
- Cathodic protection
- AC fault protection
- Lightning protection
- Mitigation of induced AC current
The standard features of a solid-state decoupler include a wide DC clamping voltage range and a high steady state DC current drain. Conversely, decoupling devices also feature a 60Hz AC impedance of 0.04 ohms and an AC steady state current 45A at 50 to 60Hz. Types of decoupling devices include 1.2kA | 2kA | 3.7kA | 5kA | 9.5kA.
Other features of a solid-state decoupler include:
- Six DC thresholds to choose from
- Four different sizes
- A submersible depth of up to two meters
- Lightning impulse ratings lightning spark voltage ratings
Benefits of a solid-state decoupler include a safe working environment where required potentials can be maintained and controlled.
Technical benefits of solid-state decoupler include:
- Higher blocking voltage capabilities
- Technically advanced
- Large, steady state current clamping strength
- Lightweight, compact design
Decoupling Device Applications
Decoupling devices are useful in a wide range of applications. Oil and gas transmission pipelines, tanks and oil facilities, bulk water pipelines, and refinery and petrochemical industries are some of the industries where decoupling devices excel. They mitigate AC induced voltage while segregating dissimilar metals that need to be AC grounded but also DC isolated.
Looking to convert AC currents to DC currents? See our Cathode Protection Rectifier.