1、PUBLISHED DOCUMENT PD CLC/TR 50454:2008 Guide for the application of aluminium electrolytic capacitors ICS 31.060.50 PD CLC/TR 50454:2008 This Published Document was published under the authority of the Standards Policy and Strategy Committee on 29 August 2008 BSI 2008 ISBN 978 0 580 60868 1 Nationa
2、l foreword This Published Document is the UK implementation of CLC/TR 50454:2008. The UK participation in its preparation was entrusted to Technical Committee EPL/40X, Capacitors and resistors for electronic equipment. A list of organizations represented on this committee can be obtained on request
3、to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Amendments/corrigenda issued since publication Date Comments TECHNICAL REPORT CLC/TR 50454 RAPPORT TECHNIQUE TECHNISCHER BERICHT April 2008 CE
4、NELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploitation in any form and by any means reserved wo
5、rldwide for CENELEC members. Ref. No. CLC/TR 50454:2008 E ICS 31.060.50 Supersedes R040-001:1998English version Guide for the application of aluminium electrolytic capacitors Guide pour lutilisation de condensateurs lectrolytiques laluminium Leitfaden fr die Anwendung von Aluminium-Elektrolyt-Konden
6、satoren This Technical Report was approved by CENELEC on 2008-02-08. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxemb
7、ourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword This Technical Report was prepared by the Technical Committee CENELEC TC 40XA, Capacitors. The text of the draft was submitted to the vote in accordance wi
8、th the Internal Regulations, Part 2, Subclause 11.4.3.3 (simple majority) and was approved by CENELEC as CLC/TR 50454 on 2008-02-08. This Technical Report supersedes R040-001:1998. _ CLC/TR 50454:2008 2 Contents 1 Scope and object 5 1.1 Scope . 5 1.2 Object . 5 2 Normative references . 5 3 Terms and
9、 definitions 6 4 Protection measures 7 4.1 Handling and transport 7 4.2 Insulation 7 5 General application limits 7 5.1 Polarity - Reverse voltage 7 5.2 Voltage . 7 5.3 Temperature range 8 5.4 Ripple current. 8 5.5 Charge - Discharge 8 6 Storage 8 7 External pressure . 9 7.1 Low air pressure 9 7.2 H
10、igh air pressure . 9 8 Self-recharge phenomenon (dielectric absorption) 9 9 Flammability (passive and active) . 9 9.1 Passive flammability 9 9.2 Active flammability . 9 10 Internal pressure and pressure relief device .10 11 Working electrolytes and contact with an electrolyte .10 12 Parallel and ser
11、ies connection .11 12.1 Parallel and series connection of capacitors . 11 12.2 Balancing resistors for voltage sharing . 12 12.3 Component failure . 15 12.4 Back-to-back connection . 15 13 Clearance and creepage distances 16 13.1 Distances inside the capacitor . 16 13.2 Distances outside the capacit
12、or . 16 14 Capacitor mounting .16 14.1 General conditions for mounting 16 14.2 Component preparation . 17 14.3 Mounting 17 14.4 Soldering 18 14.5 Transport and handling of assembled devices 18 15 Cleaning solvents 19 15.1 General 19 15.2 Cleaning solvents and process parameters 19 16 Potting and glu
13、ing .20 16.1 Potting and gluing materials 20 16.2 Curing process . 20 CLC/TR 50454:2008 3 17 Aluminium electrolytic motor start capacitors 20 17.1 Connection . 20 17.2 Mains voltage and surge 20 17.3 Duty cycle . 21 17.4 Discharge resistor 21 17.5 Operating temperature and vibration . 21 17.6 Insula
14、tion (capacitor energised) 22 17.7 Failure mechanism 22 18 Disposal of capacitors 22 Figures Figure 1 - Individual balancing resistors . 11 Figure 2 - Common centre connection . 12 Figure 3 - Group-balancing resistors 12 Figure 4 - Voltage sharing analysis 13 Figure 5 - Back-to-back connection 15 Fi
15、gure 6 - Typical motor start arrangement 20 Table Table 1 - Balancing examples 15 CLC/TR 50454:2008 4 1 Scope and object 1.1 Scope This Technical Report applies to components as described in the scope of the following standards: EN 60384-4 Fixed capacitors for use in electronic equipment - Part 4: S
16、ectional specification - Aluminium electrolytic capacitors with solid (MnO 2 ) and non-solid electrolyte EN 137100 Sectional Specification: Fixed aluminium electrolytic a.c. capacitors with non-solid electrolyte for motor starter applications - Qualification approval The information given in these d
17、ocuments apply to capacitors with non-solid electrolyte but may, in its appropriate clauses, apply to capacitors with solid electrolyte as well. In cases of doubt, the application of this document shall be discussed between the user and the manufacturer of the components. 1.2 Object Electrolytic cap
18、acitors in general and aluminium electrolytic capacitors in particular are an exception in the capacitor field because of the components close interaction of physics and chemistry. Therefore, aluminium electrolytic capacitors show, in various aspects, a technical behaviour unaccustomed to the user.
19、That could easily lead to misapplications and even to endangering of persons and goods. The aim of this application guide is to minimize these risks by providing detailed information on the specific peculiarities of the component. 2 Normative references The following referenced documents are indispe
20、nsable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 60384-1:2001 Fixed capacitors for use in electronic equipment - Part 1: Generic specificatio
21、n (IEC 60384-1:1999, mod.) EN 60384-4:2007 Fixed capacitors for use in electronic equipment - Part 4: Sectional specification - Aluminium electrolytic capacitors with solid (MnO2) and non-solid electrolyte (IEC 60384-4:2007) EN 137000:1995 Generic Specification: Fixed aluminium electrolytic a.c. cap
22、acitors with non-solid electrolyte for use with motors EN 137100:1995 Sectional Specification: Fixed aluminium electrolytic a.c. capacitors with non-solid electrolyte for motor starter applications - Qualification approval CLC/TR 50454:2008 5 3 Terms and definitions For the purposes of this document
23、, the following terms and definitions apply. 3.1 positive electrode (anode) aluminium (preferably aluminium foil) of extreme purity which is etched in most cases in order to increase the electrodes surface and, consequently, the capacitors capacitance yield 3.2 negative electrode (cathode) working e
24、lectrolyte which is a conductive liquid in the case of capacitors with non-solid electrolyte or a layer of manganese dioxide MnO 2 , conductive organic salt (e.g. TCNQ) or conductive polymer (e.g. polypyrrole) in the case of capacitors with solid electrolyte 3.3 dielectric aluminium oxide Al 2 O 3wh
25、ich is formed on the anodes surface by an anodizing process 3.4 contact element for the negative electrode a high-purity aluminium foil (“cathode foil”) in the case of capacitors with non-solid electrolyte or silver epoxy on graphite or other conductive connections in the case of capacitors with sol
26、id electrolyte 3.5 separator layers (preferably of special paper) which separate the anode foil from the “cathode foil” in the case of capacitors with non-solid electrolyte. The other purpose of these layers is to retain the working electrolyte 3.6 external insulation the metallic case of capacitors
27、 with non-solid electrolyte is not insulated against internal capacitor elements as the case may be connected e.g. through the conductive working electrolyte. Therefore, the capacitors need an external insulation sleeve if electrical insulation is required 3.7 polarity electrolytic capacitors are, o
28、n principle, polarized components. For special purposes, so- called non-polar (bipolar) capacitors may be provided. Such special types consist in principle of an internal back-to-back connection of two basically polarized elements NOTE Motorstart capacitors are bipolar (see 12.4 and Clause 17). CLC/
29、TR 50454:2008 6 3.8 sealing the internal element of a non-solid electrolytic capacitor is normally encapsulated in an aluminium case closed with a sealing material which is never perfectly gas-tight. Because of using a non-solid electrolyte, of which, some constituents are slowly diffusing through t
30、he sealing, the electrical characteristics of the capacitor are changing gradually over its entire life 4 Protection measures 4.1 Handling and transport Capacitors are generally housed in a 99,5 % aluminium case giving rise to low mechanical strength. Shocks must be avoided and manufacturers packagi
31、ng must always be used to transport capacitors. 4.2 Insulation Capacitors may be either completely or partially insulated with sleeving. It should be noted that the capacitor case is not insulated from the cathode terminal. Axial leaded capacitors have a direct contact between case and cathode termi
32、nal. Radial leaded capacitors have an undefined contact through electrolyte or other parts inside the case. Dummy pins shall be left potential-free or may be connected to the potential of the negative terminal. Metal parts other than terminals should never make contact to conducting tracks or metal
33、parts of other components. 5 General application limits 5.1 Polarity - Reverse voltage Electrolytic capacitors for d.c. applications require polarization. The polarity of each capacitor is to be checked both in circuit design and in mounting. Polarity is clearly indicated on the capacitor. For short
34、 periods a limited reverse voltage is allowed as specified in the relevant specification or by the manufacturer (e.g. 1 V for capacitors with non-solid electrolyte). Exceeding the specified reverse voltage can induce damage by causing overheating, over-pressure and dielectric breakdown and may be as
35、sociated with open circuit or short circuit conditions it is the most severe failure mechanism with aluminium electrolytic capacitors. There could even be a destruction of the capacitor. Protections are to be used if there are reverse voltage risks (see Clause 10). 5.2 Voltage Exceeding the capacito
36、rs specified voltage limits may cause premature damage (e.g. by breakdown with open or short circuit) affecting the useful life. Even destruction of the capacitor may be the consequence. 5.2.1 Rated voltage The rated voltage U Rgiven in the relevant specification or by the manufacturer is the value
37、permitted for continuous operation in the rated temperature range. 5.2.2 Surge voltage For short periods the voltage may be increased up to the surge voltage value according to EN 60384-4, 4.14, and to manufacturer specification. CLC/TR 50454:2008 7 5.2.3 Transient voltages The surge voltage value m
38、ay be exceeded for very short periods or short pulses when in accordance with the relevant specification or as specified by the manufacturer. A test method is given in an amendment to EN 60384-4, 4.22. 5.3 Temperature range The capacitors are to be used within specified temperature range. Applicable
39、 temperature ranges are given in the relevant specifications and/or in manufacturers data. A general principle is: lower ambient temperature means longer life. Therefore, electrolytic capacitors should be placed at the coolest positions wherever possible. Exceeding the permitted temperature causes o
40、verheating and over-pressure which can affect the useful life. 5.4 Ripple current The sum of d.c. voltage and maximum amplitude of ripple voltage shall remain within rated voltage and 0 V. Electrolytic capacitors are not normally designed for a.c. application (see Clauses 1 and 17). No excessive rip
41、ple current must be allowed to pass. Exceeding the ripple current specification reduces life and can induce overheating and over-pressure. Even destruction of the capacitor may be the consequence. The useful life of the capacitor is a function of the r.m.s. ripple current. Temperature, frequency and
42、 cooling conditions are other influences on the useful life. 5.5 Charge - Discharge Under the conditions defined in EN 60384-4, 4.20, or in manufacturers specifications, frequent charge/discharge operation is allowed. Exceeding charge/discharge frequency leads to a high ripple current and induces da
43、mage by overheating and overpressure or breakdown with open circuit or short circuit, leading to a reverse voltage risk (see 5.1). Even destruction of the capacitor may be the consequence. 6 Storage Capacitors should be stored at room temperature, normal atmospheric pressure, low humidity, and in ma
44、nufacturers packaging (for more details see EN 60384-1, 4.25). Storage at elevated temperature (higher than 40 C to 50 C) has a negative influence to leakage current inducing increases up to 10 times the maximum limit where the capacitors are off duty (see EN 60384-1, 4.25, and EN 60384-4, 4.17). Hi
45、gh humidity and/or high temperature may impair solderability and taping accuracy as well as the leakage current of the capacitors. Storage at conditions defined above has a negligible effect on capacitance, tangent of loss angle or equivalent series resistance, and impedance. Manufacturers recommend
46、ations (reforming procedures, etc.) shall be considered because long storage may influence the leakage current to increase beyond a reasonable level. CLC/TR 50454:2008 8 7 External pressure (Not relevant for capacitors with solid electrolyte) 7.1 Low air pressure Minimum air pressure is 8 kPa for sh
47、ort periods in accordance with EN 60384-4, 4.11.4. 7.2 High air pressure The maximum operating pressure is dependant upon size and style of the capacitor. It should be specified by the manufacturer on request. Exceeding the specified value may damage the capacitor (e.g. destroyed cases, open pressur
48、e relief device, short circuit, etc.). 8 Self-recharge phenomenon (dielectric absorption) Even if aluminium electrolytic capacitors are totally discharged, these components may afterwards develop some voltage without external influence. This self-recharge phenomenon is known as dielectric absorption
49、 or as dielectric relaxation. The capacitor is a non-ohmic conductor and has, therefore, a non-uniform distribution of the electric field. This is correlated with electric space charges within the dielectric layer. In the case of open terminals, an increasing voltage is built up in the course of the electric charges relaxation. Depending on the capacitor type and its designed voltage, such self-recharge may result in values (ev
