IEC 61950:2019

Overview

IEC 61950:2019 - Cable management systems - Specifications for extra‑heavy‑duty electrical steel conduit fittings and accessories - is the third edition (2019) international standard that defines requirements for fittings and accessories used with extra‑heavy‑duty electrical rigid steel (EHDERS) conduit conforming to IEC 60981. This technical revision narrows the scope to fittings and accessories for EHDERS conduit, introduces new/updated definitions, adds requirements for expansion, expansion‑deflection and deflection fittings, and removes requirements for cast metal boxes. The standard excludes fittings intended for potentially explosive atmospheres.

Key Topics and Technical Requirements

IEC 61950 covers functional, constructional and testing requirements for EHDERS conduit fittings and conduit bodies. Key technical areas include:

• Materials and corrosion protection
  • Metallic materials and coatings, plus non‑metallic materials (bushings, insulating liners, elastomers, gaskets).
• Mechanical construction
  • Threads, offset and angle fittings, screws, locknuts and dimensional requirements for hubs and bushings.
• Classifications
  • Concrete‑tight and wet‑location types, plus classes for expansion, expansion‑deflection and deflection fittings.
• Electrical performance
  • Requirements for electrical continuity and earth‑fault current capability for both threaded and unthreaded fittings.
• Conduit bodies and covers
  • Cross‑sectional area, openings, straight/angle/short conduit bodies, and marking requirements.
• Marking and documentation
  • Manufacturer identification, installation instructions, temperature and material coding.
• Type tests and quality assurance
  • Concrete‑tightness, wet‑locations spray test, flammability, electrical continuity, earth fault current, conductor pull, metallic‑coating thickness, thermal ageing and gasket tests, plus specific tests for expansion fittings and locknuts.

Practical Applications

IEC 61950 is intended for specification, design, manufacture, testing and selection of fittings used where extra mechanical protection and robust electrical continuity are required. Typical practical uses include:

• Heavy industrial and utility installations requiring EHDERS conduit systems
• Service‑entrance heads, nipples, hubs and conduit bodies exposed to wet locations or concrete encasement
• Installations requiring thermal or seismic movement accommodation using expansion or deflection fittings
• Product design and type‑testing of conduit fittings and accessories for procurement and compliance

Who should use IEC 61950

• Manufacturers and designers of conduit fittings and accessories
• Test laboratories and quality assurance teams performing type tests
• Specifiers, electrical engineers and procurement professionals writing technical requirements
• Contractors and installers selecting fittings for heavy‑duty EHDERS systems

Related Standards

• IEC 60981 - specifications for extra‑heavy‑duty electrical rigid steel conduit (EHDERS) (referenced by IEC 61950)
• National electrical codes and procurement specifications (for installation and compliance)