GB/T 11803-2025Marine A.C. low voltage switchboard (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part

1.Structure and drafting rules for standardization documents" Drafting. This document replaces GB/T 11803-1989 "Structure and basic dimensions of marine AC low-voltage switchboards" and GB/T 11634- 2000 "General Technical Specifications for Marine AC Low Voltage Switchboards", compared with GB/T 11803-1989 and GB/T 11634-2000, except for the structure In addition to adjustments and editorial changes, the main technical changes are as follows:

--- Added the term "distribution board" and its definition (see 3.1);

--- Changed the requirements for distribution board fuses (see 4.3.5,

4.8.7 of GB/T 11634-2000);

--- Changed the requirements for measuring instruments on distribution boards (see 4.3.6,

4.9 of GB/T 11634-2000);

--- Changed the requirements for short-circuit protection devices for distribution boards (see 4.4.1.1,

4.8.1 of GB/T 11634-2000);

--- Changed the requirements for switches and protective devices of distribution boards (see 4.4.1.5, 4.1, 4.2,

4.2.4 of GB/T 11634-2000, the requirements for "steering gear feeder protection" for feeder lines were added (see 4.4.1.5.8);

--- Changed the maximum allowable temperature rise requirements for the busbar of the distribution board (see 4.4.2.1,

4.4.2 of GB/T 11634-2000), added Neutral busbar cross-sectional area and current-carrying capacity requirements for grading busbars (see

4.3.3.5 and 4.3.3.6);

1 Scope

GB/T 11803-2025 is the Chinese national standard on marine a.c. low voltage switchboard, in the field of shipbuilding and marine structures. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 1 August 2025 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 February 2026. Classification: ICS 47.020.60, CCS U61. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This document specifies the requirements, inspection rules and marking, packaging, transportation and storage of marine AC low voltage switchboards (hereinafter referred to as "switchboards"). The corresponding test methods are described. This document applies to the main switchboard, emergency switchboard, zone switchboard and Design, manufacture and acceptance of distribution boards.

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document. For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to This document.

GB/T 191-2008 Pictorial symbols for packaging, storage and transportation

GB/T 2423.1 Environmental testing for electric and electronic products Part

3 Terms and Definitions

The following terms and definitions apply to this document.

3.1 switchboard A combination of switchgear and controlgear for distributing electrical power to a ship's electrical loads.

3.2 Main switchboard A switchboard that is supplied directly from the main power source and distributes electrical energy to various facilities on board the ship.