EXTENT OF WORK
1 General
Engage an electrical specialist who shall be responsible for specified design (as CONTRACTOR DESIGN below) and installation of the electrical for mechanical systems to meet the requirements specified herein.
Provide MCCs, circuit breakers, fuses, starters, relays, isolators, indicating lights, time switches, cables, cable support systems, audible/visual alarms, automatic or manual controls,
variable speed drives, etc. as necessary to form a complete working electrical for mechanical power and control system. Provide instruments and control loops complete with all circuits,
power supplies and other devices necessary for the correct and stable operation of each separate system.
Refer Specification Sections BUILDING SERVICES – GENERAL and BUILDING MONITORING SYSTEM – GENERAL for other general requirements.
.2 Contractor Design
(a) Detailed design of Electrical for Mechanical Power and Control Systems:
The Drawings and Specification show general equipment locations and layouts, etc that have been coordinated with the architectural, structure and other services at the time of
working developed design. The Contractor shall complete the detailing of the Contract Works to co-ordinate with the development of the Works of other Trades, including MCC
designs, subcircuit cable sizing, and subcircuit cable routes. MCC and subcircuit design shall specifically include finalisation of equipment sizes, calculation of subcircuit loads, volt
drops and cable sizes, calculation of total MCC loads under various normal and emergency operating conditions, and co-ordination of sub-main power supplies and cable sizes with
the Electrical Trade. All calculations shall be recorded.
(b) Sizing of Electrical for Mechanical Subcircuit Cables and Protection:
The Contractor shall size subcircuit cables and subciruit protection devices to achieve appropriate subcircuit volt drop and cable protection under both starting and steady state
conditions. All calculations shall be recorded.
(c) Detailed design of cable routes to co-ordinate with the Works of other Trades.
(d) Design of electrical for mechanical control systems to interface with the Control’s Specialist’s systems such that the complete installation meets the performance
requirements described in BMS – CONTROLS.
DESIGN CRITERIA
- Electrical for Mechanical systems shall comply with the Electrical (Safety) Regulations and Electrical Codes of Practice.
- Maintain total volt drop from the Main Switchboard to the powered device to not more than 2%.
- Maintain total volt drop from the MCCs to the powered device to not more than 2%.
- Design new power and control systems to be consistent with relevant existing power and control system designs.
REFERENCE DOCUMENTS
Refer specification section BUILDING MANAGEMENT SYSTEM – GENERAL, REFERENCE DOCUMENTS. Additional applicable standards shall include:
Refer specification section MECHANICAL SERVICES – GENERAL, REFERENCE DOCUMENTS. Additional applicable standards shall include:
AS 2053.1 Conduits for electrical services – General.
AS 2053.7 Rigid metallic conduits and fittings.
AS 2053.8 Flexible conduits and fittings of metal or composite materials.
AS 3000 The Wiring Rules.
AS 3008.1.2 Cables for alternating voltages up to 0.6/1 kV.
AS 3191 Electric flexible cords.
AS 3439.1 Low-voltage switchgear and control gear assemblies -Type-tested and partially type-tested assemblies.
AS 5000.1 Polymeric insulated cables for voltages up to 0.6/1 kV.
AS 5000.2 Polymeric insulated cables for voltages up to 450/750 V.
BS 88 Cartridge fuses for voltages up to 1000V AC and 1500V DC.
BS 89 Direct acting indicating electrical measuring instruments.
BS 2757 Method for determining the thermal classification of electrical insulation.
BS EN 60073 Basic and Safety principles for man-machine interface, marking and identification, coding principles for indication devices and actuators.
BS 4999 Rotating electrical machines.
BS 5000 Rotating electrical machines.
BS EN 60947 Specification for low voltage switchgear and control gear.
Pt 1:1992 General rules
Pt 3:1992 Switches, disconnectors, switch-disconnectors, and fuse combination units.
Pt 4-1:1992 Electro-mechanical contactors and motor starters.