Section
11 Electrical cables and busbar trunking systems (busways)
11.1 General
11.1.1 The general requirements of electrical cables, optical fibre cables and
busbar trunking systems (busways) are given in Pt 6, Ch 2, 11.1 General of the Rules for Ships and IEC 61892-4 (all
parts), Mobile and fixed offshore units – Electrical installations – Part 4:
Cables, which are to be complied with where applicable
11.2 Testing
11.2.1 The requirements for testing are given in Pt 6, Ch 2, 11.2 Testing of the Rules for Ships, which are to be complied
with where applicable. Additions or amendments to these requirements are given in
the following paragraph(s) of this sub-Section.
11.2.2 For cables with rated voltage above 30 kV a.c. guidance for requirements
and test methods can be obtained from IEC 60840, Power Cables with extruded
insulation and their accessories for rated voltages above 30 kV (Um = 36 kV) up
to 150 kV (Um = 170 kV) – Test methods and requirements.
11.3 Voltage rating
11.3.1 The requirements for voltage rating are given in Pt 6, Ch 2, 11.3 Voltage rating of the Rules for Ships, which are to be complied
with where applicable.
11.4 Operating temperature
11.5 Construction
11.5.1 The requirements for construction are given in Pt 6, Ch 2, 11.5 Construction of the Rules for Ships, which are to be complied
with where applicable.
11.6 Conductor size
11.6.1 The requirements for conductor sizing are given in Pt 6, Ch 2, 11.6 Conductor size of the Rules for Ships, which are to be complied
with where applicable. Additions or amendments to these requirements are given in
the following paragraph(s) of this sub-Section.
11.6.2 The cable current ratings given in Pt 6, Ch 2, 11.6 Conductor size 11.6.5 and Pt 6, Ch 2, 11.6 Conductor size 11.6.5 in Pt 6, Ch 2, 11.6 Conductor size of the Rules for Ships are based on the maximum
rated conductor temperatures given in Pt 6, Ch 2, 11.4 Operating temperature 11.4.2 in Pt 6, Ch 2, 11.4 Operating temperatureof the Rules for Ships. When cable sizes are
selected on the basis of precise evaluation of current rating based upon
experimental and calculated data, details are to be submitted for consideration.
Alternative short-circuit temperature limits, other than those given in Table Pt 6, Ch 2, 11.6 Conductor size 11.6.5, may be applied using the data
provided in:
- IEC 60724, Short-circuit temperature limits of electric
cables with rated voltages of 1kV (Um=1,2kV) and 3kV (Um=3,6kV); or
- IEC 60986, Short-circuit temperature limits of electric
cables with rated voltages from 6kV (Um=7,2kV) and up to 30kV
(Um=36kV).
- IEC 61443, Short-circuit temperature limits of electric
cables with rated voltages above 30 kV (Um = 36 kV).
Alternative short-circuit temperature limits provided in an acceptable
and relevant National Standard may also be considered.
11.7 Correction factor for cable current
rating
11.8 Installation of cables
11.8.1 The requirements for installation of cables are given in Pt 6, Ch 2, 11.8 Installation of electric and optical fibre cables of the Rules for Ships and IEC 61892-6:2007,
Mobile and fixed offshore units – Electrical installations – Part 6:
Installation, Section 5, which are to be complied with where applicable.
Additions or amendments to these requirements are given in the following
paragraph(s) of this sub-Section.
11.8.3 All cables as far as is practicable are to be located outside areas at
risk of cryogenic spill.
11.9 Mechanical protection of cables
11.10 Cable support system
11.10.1 The requirements for the cable support system are given in Pt 6, Ch 2, 11.10 Cable support systems of the Rules for Ships, which are to be
complied with where applicable. Additions or amendments to these requirements are
given in the following paragraph(s) of this sub-Section.
11.10.2 The distances between the points at which the cable is supported (e.g.
distances between ladder rungs, support brackets, hangers, etc.) are to be chosen
according to the construction of cable (i.e. size and rigidity) and the probability
of vibration and are to be generally in accordance with those given in Pt 6, Ch 2, 11.10 Cable support systems 11.10.3 in Pt 6, Ch 2, 11.10 Cable support systems of the Rules for Ships or manufacturer's
recommendations, whichever requires a smaller distance between supports.
11.11 Penetration of bulkheads and decks by
cables
11.12 Installation of electric and optical fibre
cables in protective casings
11.13 Non-metallic cable support systems,
protective casings and fixings
11.14 Single-core electric cables for
alternating current
11.15 Electric cable ends
11.16 Joint and branch circuits in cable
systems
11.17 Busbar trunking systems
(bustrunks)
11.17.1 The requirements for busbar trunking systems (bustrunks) are given in
Pt 6, Ch 2, 11.17 Busbar trunking systems (bustrunks) of the Rules for Ships, which are to be complied
with where applicable. Additions or amendments to these requirements are given in
the following paragraph(s) of this sub-Section.
11.17.2 Where the busbar trunking system is employed for circuits on and below
the freeboard deck, arrangements are to be made to ensure that circuits on other
decks are not affected in the event of partial flooding under the normal angles of
inclination given in Pt 6, Ch 2, 1.10 Inclination of the unit for essential electrical equipment.
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