Totally Integrated Power - Planning of Electric Power Distribution: Products & Systems, Medium Voltage (Module 1: Medium-Voltage Switchgear and Protection/Switching Devices)

Overview

The module lists the factors and parameters that drive switchgear choice. IEC 62271-200 covers metal-enclosed switchgear above 1 kV up to 52 kV, and the key ratings per IEC 62271-1 are Ur, Up, fr, Ir, Ik, Ip and tk.

Switchgear is classified by construction, insulation (air or gas), single or double busbar, loss of service continuity (LSC) and internal arc classification (IAC). Air-insulated primary switchgear is LSC 2B with single or double busbar; gas-insulated primary and secondary types are LSC 2, with some panel types LSC 1.

The tabulated internal arc classes run from IAC A FLR 50 kA 1 s (17.5 kV, 4,000 A busbar) down to IAC A FL/FLR 20-21 kA 1 s for compact secondary units. The sealed 8DJH gas-insulated switchgear has an expected service life of at least 35 years, realistically 40-50, limited by switching-device operating cycles.

The module also gives room-planning data, vacuum circuit-breakers and digital protection relays with application examples. Data centres are listed among the typical secondary-distribution applications for compact ring-main type GIS (RRT, RRT-R and RRT-RRT combinations).

Key points

1. IEC 62271-200 covers metal-enclosed switchgear above 1 kV up to 52 kV; key ratings Ur, Up, fr, Ir, Ik, Ip, tk.
2. Classification: construction, insulation (air or gas), single/double busbar, LSC and IAC.
3. Air-insulated primary switchgear is LSC 2B; gas-insulated primary/secondary types are LSC 2, some panels LSC 1.
4. Internal arc classes range from IAC A FLR 50 kA 1 s (17.5 kV, 4,000 A busbar) to IAC A FL/FLR 20-21 kA 1 s for compact secondary units.
5. Sealed 8DJH GIS service life is at least 35 years, realistically 40-50, limited by switching-device operating cycles.
6. Data centres are named among typical secondary-distribution applications for compact ring-main GIS.

Using it in design

• Store Ur, Up, Ir, Ik/tk, Ip, LSC category, IAC rating and accessibility, insulation medium and busbar scheme in the MV switchgear catalogue.
• Require the IAC current and duration to be at least the prospective fault at the board.
• For concurrently maintainable designs prefer LSC 2/2B with double or sectionalised single busbar.
• Use a 35-50 year service life as the default for sealed GIS in lifecycle cost.

Who should read it

Electrical designers selecting and specifying MV switchgear for data-centre supply.

Related standards

• IEC 62271-1
• IEC 62271-200
• IEC 62271-100

Publication details

Authors

Siemens

Publisher

Siemens

Year

2017

Document number

TIP planning manual vol. 2, module 1

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation