15 MANUFACTURING DEVIATION and DRIFT 15.1 Those parts of controls providing a TYPE 2 ACTION shall have adequate consistency of manufacture with regard to their declared OPERATING VALUE, OPERATING TIME, or OPERATING SEQUENCE. In some countries, MANUFACTURING DEVIATION and DRIFT are expressed as separate tolerances to the declared OPERATING VALUE. For some controls with TYPE 2 ACTION, allowable values of MANUFACTURING DEVIATION and DRIFT are specified. The consistency is then determined, using prescribed apparatus, by measurement of the OPERATING VALUE of the sample and comparison to the declared OPERATING VALUE. 15.1DV D2 Modification of 15.1 by adding the following text after the note: The 2in some countries2 clause is applicable in the USA. 15.2 Compliance is checked by the appropriate tests of this clause. 15.3 For those controls which are completely or partially destroyed during their normal OPERATION, the tests of the appropriate subclauses of clause 17 are deemed to be sufficient. 15.4 For those controls which are dependent on the method of mounting on, or incorporation in an equipment for their OPERATION the MANUFACTURING DEVIATION and the DRIFT shall be declared separately and be comparative values. The declared MANUFACTURING DEVIATION should be expressed as a bandwidth or spread (for example 10 K) and the DRIFT by an alteration of value (for example ? 10 K or + 5 K, - 10 K) 15.5 The consistency shall be determined as follows: 15.5.1 Test apparatus used shall be such that the control is mounted in the manner declared by the manufacturer. 15.5.2 For SENSING CONTROLS the apparatus shall preferably be such that the normal OPERATION of the control is used to control the apparatus. 15.5.3 However, because this test is made to determine comparative values rather than RESPONSE VALUES, the form of the apparatus is not critical. It should, however, simulate as nearly as is practicable the conditions of service. 15.5.4 The electrical conditions of the test shall normally be VR max and IR max unless different conditions have been declared in requirement 41 of table 7.2. However, the OPERATION of the control shall be sensed by a suitable device with a sensing current not exceeding 0,05 A. 15.5.5 For SENSING
17 Endurance 17.1 General requirements 17.1.1 Controls, including those submitted in or with an equipment, shall withstand the mechanical, electrical and thermal stresses that occur in NORMAL USE. 17.1.2 Controls with TYPE 2 ACTIONS shall operate such that any OPERATING VALUE, OPERATING TIME or OPERATING SEQUENCE does not change by an amount greater than the declared DRIFT. 17.1.2.1 Compliance with 17.1.1 and 17.1.2 is checked by the tests of 17.1.3 as indicated in 17.16. 17.1.3 Test Sequence and Conditions 17.1.3.1 In general, the sequence of tests is: - an ageing test specified in 17.6 (This test applies only to those actions classified as Type 1.M or 2.M); - an overvoltage test of AUTOMATIC ACTION at accelerated rate specified in 17.7. (In some countries this test is replaced by an overload test); - a test of AUTOMATIC ACTION at accelerated rate specified in 17.8; - a test of AUTOMATIC ACTION at slow rate specified in 17.9. (this test applies only to SLOW-MAKE, SLOW-BREAK AUTOMATIC ACTIONS); - an overvoltage test of MANUAL ACTION at accelerated speed specified in 17.10. (in some countries this test is replaced by an overload test); - a test of MANUAL ACTION at slow speed specified in 17.11; - a test of MANUAL ACTION at high speed specified in 17.12. (this test applies only to actions with more than one pole, and where polarity reversal occurs during the OPERATION); - a test of MANUAL ACTION at accelerated speed specified in 17.13. From: [email protected] [mailto:[email protected]]On Behalf Of Kunde, Brian Sent: Wednesday, November 18, 2009 8:37 AM To: [email protected] Subject: PTC Test Requirements According to IEC/EN 60950 section 2.5b, a positive temperature coefficient device (PTC) can be used to limit current for a limited power source circuit. It says the PTC has to "pass the test specified in IEC 60730-1, clauses 15, 17, J.15 and J.17". I don't have this standard. Can someone outline the test requirements for me? I'm trying to avoid adding another standard to our library unless we really need to. Application: Sometimes we would like to supply 24Vdc to an I/O port to operate a device outside the fire enclosure. I assume a PTC or Pico Fuse can be used for this application. We drive the I/O circuit with a programmable High-Side Driver programmed to 4 amps max but someone suggested that we cannot rely on it for safety in this application. Any other suggestions? Thanks to all, The Other Brian - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
