Section 5 Switchgear assemblies, switchgear and fusegear - Construction and testing
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Inland Waterways Ships, July 2022 - Part 6 Control, Electrical and Fire - Chapter 2 Electrical Installations - Section 5 Switchgear assemblies, switchgear and fusegear - Construction and testing

Section 5 Switchgear assemblies, switchgear and fusegear - Construction and testing

Parent topic: Chapter 2 Electrical Installations

5.1 Switchgear assemblies

5.1.1 Switchboards, section boards and distribution boards are to be so installed that live parts are sufficiently guarded and adequate space is provided for maintenance, also they are to be protected where necessary in way of pipes and to be constructed from, or enclosed with, non-flammable non-hygroscopic material.

5.1.2 All measuring instruments and all apparatus controlling circuits are to be clearly and indelibly labelled for identification purposes. An indelible label is to be permanently secured to, or adjacent to, every fuse and every circuit-breaker, and marked with particulars of the full load current of the generator or cable which the fuse or circuit-breaker protects. Where inverse time limit and/or reverse current devices are provided in connection with a circuit-breaker, the appropriate settings of these devices are to be stated on the label. Nameplates are to be of flame-retardant material.

5.2 Instruments

5.2.1 Sufficient instrumentation is to be provided for measuring voltage, current, frequency and power for alternating current generators greater than 50 kW.

5.2.2 Where alternating current generators are required to operate in parallel, synchronizing arrangements are to be fitted.

5.3 Instrument transformers

5.3.1 The secondary windings of instrument transformers are to be earthed.

5.4 Switchgear

5.4.1 Circuit-breakers and switches are to be of the air break type and are to be constructed in accordance with an acceptable National or International Standard.

5.4.2 Reports of tests to establish the capacity of circuit-breakers, are to be submitted for consideration when required.

5.4.3 Overcurrent releases are to be calibrated in amperes, and settings marked on the circuit-breaker.

5.5 Fuses

5.5.1 Fuses are to comply with an acceptable National or International Standard.

5.5.2 Fuse-links and fuse-bases are to be marked with particulars of rated current and rated voltage. Each fuse position is to be permanently and indelibly labelled with the current-carrying capacity of the circuit protected by it and with the appropriate approved size of fuse or replaceable element.

5.6 Testing

5.6.1 Before installation, switchboards complete or in sections with all components, are to pass the following tests at the manufacturer’s works and a certificate furnished. A high voltage test is to be carried out on all switching and control apparatus for systems greater than 60 V with a test voltage of 1000 V plus twice the rated voltage (minimum 2000 V) at any frequency between 25 and 100 Hz for one minute applied between:

  1. all current-carrying parts connected together and earth; and

  2. between current-carrying parts of opposite polarity or phase.

5.6.2 For systems of 60 V or less, the test shall be at 500 V for one minute.

5.6.3 Instruments and ancillary apparatus may be disconnected during the high voltage test.

5.6.4 Immediately after the high voltage test, the insulation resistance between:

  1. all current-carrying parts connected together and earth, and

  2. between current-carrying parts of opposite polarity or phase,

shall be not less than one MΩ when tested with a direct current voltage of at least 500 V.

Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.