开关柜安装用变压器及其他设备

12.1.3 Impedance voltage, voltage variation and short-circuit current withstand

Voltage drops

The impedance voltage U_Kr is defined as that voltage having the rated frequency which must be applied to the primary side of a transformer so that the rated current I_r flows when the secondary terminals are short-circuited. Since only the short-circuit impedance is present in the circuit,

U_Kr = √3 · I_r · Z_K.

The rated impedance voltage is usually stated as a percentage of the voltage rating U_r of the winding to which the voltage is applied:

u_Kr = U_Kr/U_r · 100 %.

The impedance voltage is composed of the ohmic voltage drop (U_R, u_R) which is in phase with the current, and the reactive voltage (U_X, u_X), which leads the current in time by 90°.

Ohmic voltage drop:

u_Rr = P_Kr/S_r · 100 % = Impedance losses at rated power / rated power · 100 %.

Reactive voltage:

u_Xr = √(u_Kr² - u_Rr²).

In the case of a partial load, the short-circuit voltage U_K is proportional to the load on the transformer:

u_K = u_Kr · I/I_r = u_Kr · S/S_r

For distribution transformers, according to DIN 42500 a rated impedance voltage u_Kr is allocated to each power rating S_r, Table 12-3.

Table 12-3 Rated impedance voltage u_Kr

Rated output Sr in kVA1)	uKr
50 (63) 100 160 (200) 250 (315) 400 (500) 630	4 %
630 (800) 1000 (1250) 1600 (2000) 2500	6 %

1) Rated outputs not in brackets are preferred.

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2 Scope

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EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 10216-3

May 2002

ICS 23.040.10; 77.140.75

English version

Seamless steel tubes for pressure purposes –
Technical delivery conditions

Part 3: Alloy fine grain steel tubes

Tubes sans soudure en acier pour service sous pression – Conditions techniques de livraison – Partie 3: Tubes en acier allié à grain fin

Nahtlose Stahlrohre für Druckbeanspruchungen – Technische Lieferbedingungen – Teil 3: Rohre aus legierten Feinkornbaustählen

This European Standard was approved by CEN on 2002-04-25.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member.

The European Standards exist in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom.

CEN

European Committee for Standardization

Comité Européen de Normalisation

Europäisches Komitee für Normung

Management Centre: rue de Stassart 36, B-1050 Brussels

© 2002. CEN – All rights of exploitation in any form and by any means reserved worldwide for CEN national members.

Ref. No. EN 10216-3 : 2002 E

Contents

Section	Page
Foreword	3
Introduction	4
1 Scope	4
2 Normative references	5
3 Definitions	5
3.1 DN	5
3.2 PN	5
4 Designations	6
4.1 Range of PN designations	6
4.2 Range of DN (nominal sizes)	6
4.3 Gasket types	6
4.4 Information to be supplied by the purchaser	6
5 Gasket designs	6
6 Gasket types	7
7 Dimensions	7
8 Marking	10
Annex A (informative) Information to be supplied by the purchaser	10
Annex B (informative) A-deviation	11

:current

Foreword

This document (EN 10216-3:2002) has been prepared by Technical Committee EC/TC 29, "Steel tubes and fittings for steel tubes", the secretariat of which is held by UNI.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2002, and conflicting national standards shall be withdrawn at the latest by November 2002.

This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document.

Other Parts of EN 10216 are:

Part 1:	Non-alloy steel tubes with specified room temperature properties
Part 2:	Non-alloy and alloy steel tubes with specified elevated temperature properties
Part 4:	Non-alloy and alloy steel tubes with specified low temperature properties
Part 5:	Stainless steel tubes

Another European Standard series covering tubes for pressure purposes is:

EN 10217:

Welded steel tubes for pressure purposes

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

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1 Scope

This Part of EN 10216 specifies the technical delivery conditions in two test categories for seamless tubes of circular cross section, made of weldable alloyed fine grained steel.

2 Normative references

This European Standard incorporates by date or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For date references, subsequent amendments to or revisions of, any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments).

The requirements of this European Standard rule when they differ from those in the standards and documents referred to below:

EN 10002-1, Metallic materials - Tensile testing - Part 1: Method of test (at ambient temperature).

EN 10002-5, Metallic materials - Tensile testing - Part 5: Method of testing (at elevated temperature).

EN 10020, Definitions and classification of grades of steel.

EN 10021, General technical delivery requirements for steel and iron products.

EN 10045-1, Metallic materials - Charpy impact test - Part 1: Test method.

EN 10052, Vocabulary of heat treatment terms for ferrous products.

EN 10204, Metallic products - Types of inspection documents.

EN 10027-1, Designation systems for steels - Part 1: Steel names, principle symbols.

EN 10027-2, Designation systems for steels Part 2: Numerical systems.

ENV 10220, Seamless and welded steel tubes - Dimensions and masses per unit length

EN 10233, Metallic materials - Tubes - Flattening test.

EN 10234, Metallic materials - Tubes - Drift expanding test.

EN 10236, Metallic materials - Tubes - Ring expanding test.

EN 10237, Metallic materials - Tubes - Ring tensile test.

EN 10246-1, Non-Destructive Testing of steel tubes Part 1: Automatic electromagnetic testing of seamless and welded (except submerged arc welded) ferromagnetic steel tubes for verification of hydraulic leak-tightness.

EN 10246-5, Non-Destructive Testing of steel tubes - Part 5: Automatic full peripheral magnetic transducer/flux leakage testing of seamless and welded (except submerged arc-welded) ferromagnetic steel tubes for the detection of longitudinal imperfections.

EN 10246-6, Non-Destructive Testing of steel tubes - Part 6: Automatic full peripheral ultrasonic testing of seamless steel tubes for the detection of transverse imperfections.

EN 10246-7, Non-Destructive Testing of steel tubes - Part 7: Automatic full peripheral ultrasonic testing of seamless and welded (except submerged arc welded) steel tubes for the detection of longitudinal imperfections.

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