Section 6 Electrical equipment

6.1.1 The electrical installation is to be designed, constructed and installed in accordance with the requirements of Pt 6, Ch 2 Electrical Engineering.

6.1.2 Components, including, but not limited to control equipment, sensors, slip rings and cable connections are to withstand the vibration levels as specified by a relevant International or National Standard acceptable to LR. Selection of an acceptable standard will be dependent on the intended operational profile of the ship.

6.1.3 Means are to be provided to prevent electrical currents flowing across shaft bearings, which may cause their premature failure.

6.1.4 Steering gear electrical systems are to comply with Pt 5, Ch 19, 5 Electric power circuits, electric control circuits, monitoring and alarms.

6.1.5 Details are to be submitted to demonstrate the suitability of cables and busbars intended to operate at temperatures exceeding 95°C, see Pt 6, Ch 2, 7.2 Busbars 7.2.2 and Pt 6, Ch 2, 11.4 Operating temperature 11.4.3.

6.2.1 Where slip rings are incorporated in the design, the details of the following are to be submitted for consideration:

1. temperature rise test reports;

2. maximum permitted temperature ratings and design operating temperatures for materials;

3. where applicable, arrangements for forced air or liquid cooling;

4. for data communication link slip rings, evidence to demonstrate compliance with Pt 6, Ch 1, 2.11 Data communication links 2.11.3;

5. suitability for use under the conditions of vibration expected to arise in normal operation;

6. evidence of satisfactory operation under the normal angles of inclination given in Pt 6, Ch 2, 1.10 Inclination of ship;

7. cable securing arrangements; and

8. evidence of electromagnetic compatibility of control, alarm and safety systems with power circuits.

6.2.2 Where forced cooling is used on slip rings, an alarm is to be initiated to indicate the failure of the forced cooling and it is to be possible to operate the slip ring at a reduced power level defined by the Manufacturer in the event of failure of the forced cooling.

6.2.3 Slip ring assemblies are to be provided with an enclosure with a degree of protection of at least IP23, according to IEC60529: Degrees of protection provided by enclosures (IP Code).

6.2.4 Adequate provisions are to be taken to ensure that personnel are not endangered if an arc fault occurs within the slip ring assembly, see also Pt 6, Ch 2, 8.1 General 8.1.1.

6.2.5 Tests at the slip ring assembly manufacturers works are to include type and routine tests according to IEC 60092-501: Electrical installations in ships – Part 501: Special features – Electric propulsion plant.