Section 5 General Requirements of Electrical Equipment

501. General

1. The design and installation of electrical equipment are to be such as to minimize the risk of fire or other electrical accidents due to its failure.

2. Electrical equipment is to be suitable construction for marine use and provided with effective pro- tective enclosure for environmental conditions in which the equipment is installed.

3. Insulating materials and windings of electrical equipment are to have sufficient resistance for mois- ture, sea air and oil vapour.

502. System voltage 【See Guidance】

1. System voltage is not to exceed:

(1) 500V for generators, power equipment, cooking and heating equipment connected to fixed wiring.

(2) 250V for lightings, heaters in cabins and public rooms, and other appliances than mentioned in (1).

2. In case where system voltage exceeding the required prescribed in Par 1 is adopted, they are to be subject to the approval by the Society in advance.

503. Clearance and creepage

1. The clearances and creepages between live parts and between live parts and earthed metals are to

be adequate for the working voltage having regard to the nature

operating conditions.

2. The clearances and creepages inside the terminal box of rotating

of the insulating materials and

machinery, switchboard bussbar

and the controlling equipment, etc. are to comply with the requirements in Pt 6, Ch 1, 201., 303., 701. and 706 of the Rules for the Classification of Steel Ships.

504. Limits of temperature rise

1. Ambient temperature

For all electrical equipment, the following ambient temperatures are recognized as standard:

(1) For all equipment located in compartment where the boilers are installed and on weather decks: 45 ℃ (for rotating machinery 50 ℃).

(2) For all equipment located in other spaces than specified in Par 1: 40 ℃

2. Limits of temperature rise

The limits of temperature rise of generators, motors, switchboards, transformers and starters for mo- tors are to comply with the requirements in Pt 6, Ch 1 of the Rules.

Rules for the Classification of Steel Barges 2015 77