IEC 61892-2:2012

Overview

IEC 61892-2:2012 - "Mobile and fixed offshore units - Electrical installations - Part 2: System design" is an international standard for the system design of electrical installations on offshore petroleum units. It covers mobile and fixed units used for drilling, production, processing and storage, including pipeline/pumping (pigging) stations, compressor stations and exposed single buoy moorings. The standard applies to permanent, temporary, transportable and hand‑held installations for a.c. systems up to 35 000 V and d.c. systems up to 1 500 V (nominal). It excludes fixed medical equipment and the electrical installations of tankers.

Key topics and technical requirements

IEC 61892-2 focuses on practical system design elements for offshore electrical installations. Major technical topics include:

• Sources of electrical power - requirements for main and emergency power, starting arrangements for emergency generators and provisions for renewable sources (photovoltaic, eolic). (See Clause 4; emergency power consolidated in Clause 4.3.)
• System earthing - neutral earthing methods, earthing for systems up to/above 1 000 V, earthing resistors and connection to the hull/structure. (Clause 5)
• Distribution systems - AC and DC distribution topologies (TN, IT), DC system types, specified AC/DC voltages and control voltages. (Clause 6)
• Distribution design requirements - final circuits, lighting circuits, socket‑outlets, shore connections, motor circuits and starting arrangements. (Clause 7)
• Load modelling and studies - load/demand factors, load flow, short‑circuit, protection coordination and harmonic/power quality studies. (Clauses 8–9)
• Protection - selection and coordination of protective devices, generator/transformer/motor protection, undervoltage/overvoltage measures and rated breaking/making capacities. (Clause 10)
• Lighting and emergency lighting - general, emergency and escape lighting, navigation/obstruction signals and luminaires. (Clause 11)
• Control and instrumentation - safety, segregation, EMC, monitoring and design for safety‑critical and fire/gas protection control systems. (Clause 12)

Notable technical updates in this edition: d.c. voltage updated to 1 500 V for series consistency; nominal a.c. volt tables aligned with IEC 60038; earthing conductor cross‑sectional requirements depend on earthing arrangement; emergency stop requirement added for motor‑driven fuel‑oil pumps.

Practical applications and who uses it

IEC 61892-2 is used by:

• Offshore electrical and systems engineers designing platform and floater distribution systems
• EPCI contractors and integrators responsible for power system layouts and protection coordination
• Asset owners/operators planning upgrades, shore connections and emergency power schemes
• Classification societies and regulatory authorities reviewing compliance for offshore units
• Control, instrumentation and lighting designers ensuring EMC, safety and emergency requirements

Typical applications: design of power generation and distribution on drilling rigs, FPSOs, production platforms, compressor/pumping stations and single buoy moorings.

Related standards

• IEC 61892 series (other parts covering installation, selection of equipment and verification)
• IEC 60038 (standard voltages) - used to align nominal a.c. voltage tables

Keywords: IEC 61892-2, offshore electrical installations, system design, mobile and fixed offshore units, emergency power, system earthing, distribution systems, offshore petroleum industry.