| Publication CODE |
Title |
| IEC 60287-1-2:2023 (2023-05) |
ELECTRIC CABLES - CALCULATION OF THE CURRENT RATING - PART 1-2: CURRENT RATING EQUATIONS (100 % LOAD FACTOR) AND CALCULATIONS OF LOSSES - SHEATH EDDY CURRENT LOSS FACTORS FOR TWO CIRCUITS in FLAT FORMATION |
| |
| Price Excl. VAT |
Total number of pages, tables and drawings |
|
201.00 €
|
30. |
Description
IEC 60287-1-2:2023 provides a method for calculating the eddy current losses in the metallic sheaths of single-core cables arranged as a three-phase double circuit in flat formation. The sheaths are bonded at one point or are cross-bonded so that there are no significant sheath circulating currents. Where metallic sheaths are bonded at both ends there are significant circulating currents which result in a lower current-carrying capacity. A method of calculating circulating current losses for double circuits is provided in IEC 60287-1-3.
The method descibed in this document provides coefficients which are applied as corrections to the loss factors for the sheaths of one isolated three-phase circuit. These corrections are negligible for cables where the parameter m is less than approximately 0,1 (m = '/(Rs · 107)), which corresponds to a sheath longitudinal resistance higher than 314 µ'/m at 50 Hz.
Consequently, the method is used for most sizes of aluminium-sheathed cables, but is not required for lead-sheathed cables unless they are unusually large.
The coefficients are provided in tabular form and have been computed from fundamental formulae for sheath losses, the evaluation of which calls for expertise in computer programming which will possibly not be readily available in general commercial situations. The development of simplified formulae for some of the tabulated coefficients is under consideration.
Losses for cables in a single circuit is covered in IEC 60287-1-1.
|
| Class |
C990
(IEC PUBLICATIONS IEC PUBLICATIONS)
|
| Committee |
TC 20
ELECTRIC CABLES (HIGH-VOLTAGE AND LOW-VOLTAGE) (Full Committee)(20A/WG16+20B/WG17+20C/WG18)
|
| Responsible |
Monsieur POLART Jules, Ingénieur
Chaussée de Brunehault, 380
7140
MORLANWELZ
Phone: 064 / 45 16 83
Fax: 064 / 45 16 83
E-mail: jules.polart@ceb-bec.be
|
| BEC Approval |
2023-05-12 |
| ICS-Code (International Standards Classification) |
29.060.20
|
| NBN Status |
New |
|
| IEC publication date |
2023-05-12 |
| IEC stability date |
2030-12-31 |
| IEC file modification date |
2023-05-12 |
| IEC last modification date |
2023-05-12 |
|
