Overview
EN 61334-3-21:1996 (CLC) is a technical standard in the EN 61334 series that specifies requirements for MV phase-to-phase isolated capacitive coupling devices used in distribution line carrier systems. The standard establishes definitions, requirement criteria, methods of testing and rated values for these coupling devices used in medium-voltage (MV) mains signalling and distribution automation.
Key topics and requirements
The standard focuses on the following core areas:
- Definitions and terminology relevant to phase-to-phase isolated capacitive coupling devices and distribution line carrier systems.
- Performance and rated values, specifying the electrical and functional characteristics that manufacturers and users should expect.
- Requirements for safe and reliable operation when coupling carrier signals onto MV distribution lines while maintaining phase-to-phase isolation.
- Methods of testing, describing how to verify compliance with the specified requirements and rated values.
- Scope for application within mains signalling and distribution automation contexts on medium-voltage networks.
(Keyword highlights: EN 61334-3-21:1996, MV phase-to-phase isolated capacitive coupling device, distribution line carrier systems, mains signalling requirements.)
Applications
EN 61334-3-21:1996 is directly applicable to:
- Distribution automation projects using line carrier communications to convey control, telemetry and protection signals over MV networks.
- Selection and procurement of phase-to-phase isolated capacitive coupling devices by utilities and system integrators.
- Product design and manufacturing, guiding vendors on required device characteristics and testability for MV mains-signalling applications.
- Type testing and conformity assessment performed by test laboratories to demonstrate compliance with mains signalling requirements.
Who should use this standard
Primary users include:
- Electric utilities and distribution system operators specifying coupling devices for line carrier systems.
- Manufacturers and suppliers of MV coupling devices and distribution automation equipment.
- Testing and certification laboratories assessing device conformity.
- System integrators, design engineers and consultants working on MV mains signalling and distribution automation solutions.
Related standards
- EN 61334 series (mains signalling and distribution line carrier systems) - EN 61334-3-21 forms part of this broader family of documents addressing mains signalling requirements.
- ICS classification: 33.040.50 (Lines, connections and circuits).
EN 61334-3-21:1996 helps ensure consistent definitions, measurable rated values and reliable test methods for MV phase-to-phase isolated capacitive coupling devices, promoting interoperability and safety in distribution automation and mains signalling applications.