sppower

System Listings

Specialist Power

System Overview
General power services are generally provided within the premises for general use. However, it is common for certain items of specialist electrical equipment to be installed.

Such equipment may include:

Mechanical services supplies (Air Handling Units, Chillers, Boilers etc.)
Lift Supplies.
Large machinery with abnormal supply requirements etc.
Data Equipment and IT supplies.
Essential services

The exact types of specialist supplies required will obviously depend upon the building and it's use.

Specialist power may be derived from the final circuit distribution boards, sub distribution system or the mains intake depending upon size and factors such as security of supplies etc.

Systems Available and Applications

Specialist power may be derived from the final circuit distribution boards, sub distribution system or the mains intake depending upon size and factors such as security of supplies etc.

Factors such as the following should be taken into account.

Lift Supplies - These may require sizable supplies due to high starting currents. Also, the supply may have to be provided with a backup or standby supply in certain buildings if it is to be used as a "fire fighting lift".

Mechanical Supplies - These vary greatly in type and size. However, many mechanical loads have large current requirements and so will have to be given special consideration. Mechanical plant is often provided with variable speed drives. Such drives contain SCR devices and can induce harmful harmonics on to the electrical supply. Hence harmonic filtering may be needed. It is often desirable to serve mechanical equipment via a separate supply systems to avoid such problems affecting other equipment.

Electronic Equipment. - A whole range of specific criteria may apply to supplies serving electronic equipment. A major factor may be the effect that other equipment in the building has on such sensitive equipment. ElectrOmagnetic Compatibility (EMC) requirements play a major role in the reduction of cross interference between equipment. Electronic equipment may need dedicated or "Clean" supplies, also, standby generation or UPS systems may be needed. Special "clean earth" systems may be applicable.

Many other forms of specialist power may be required. All equipment proposed to be installed in the building should be considered for specialist power needs.

Legislation & Guidelines

British Standards.

Also refer to The British Standards Institution

PD 6582:1993 "Electromagnetic compatibility (EMC)". Guide to generic EMC standards. Guidance on the selection and use of standards for compliance with Directive 89/336/EEC (EMC Directive).
BS 5733:1979 "Specification for general requirements for electrical accessories". Electrical wiring accessories for installation purposes, not specifically covered by other British Standards, for use in single phase a.c. or d.c. circuits, for voltages between conductors exceeding extra low voltage but not exceeding 250 V, and current not exceeding 45 A.
BS 7671:2001 "Requirements for electrical installations". IEE Wiring Regulations. Sixteenth edition. This is the all encompassing "Bible" in relation to the design, installation and use of electrical installations and equipment in buildings
DD 240:Part 1:1997 "Fire safety engineering in buildings". Guide to the application of fire safety engineering principles Provides a framework for an engineering approach to the achievement of fire safety in buildings by giving guidance on the application of scientific and engineering principles to the protection of people and property from fire.

Combined Standards

BS IEC 1000-2-5:1995 "Electromagnetic compatibility (EMC)". Environment. Classification of electromagnetic environments. Basic EMC publication

International Standards