1、- _. _- EIA Lb-13E 78 3234b00 0028572 7 / ANSI/EIA RS-186-E-78 Approved October .27, 1978 .- IA STANDARD STANDARD TEST METHODS FOR PASSIVE ELECTRONIC COMPONENT PARTS METHOD 13: INSULATION RESISTANCE TEST -RSl8643E (Revision of RS-186-0, Method 13) OCTOBER 1978 EZlgineering Depcsrtmeirf EECTRONiC QND
2、USTRIES ASSOCIATION 1 EIA 386-33E 78 m 3234600 0028573 O m NOTICE EIA engineering standards are designed to serve the public interest through eliminating mis- understandings between manufactlirers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchase
3、r in selecting and obtaining with mini- mum delay the proper product for his particular need. Existence of such standards shall not in any respect preclude any member or non-member of EIA from manufacturing or selling products not conforming to such standards, nor shall the existence of such standar
4、ds pre- clude their voluntary use by those other than EIA members whether the standard is to be used either domestically or internationally. Recommended standards are adopted by EU without regard to whether or not their adop- tion may involve patents on articles, materials, or processes. By such act
5、ion, EU does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the recommended standards. This EIA Recommended Standard is considered to have international standardization impli- cations, but the International Electrotechnical Commission has
6、 chosen to write this test procedure for each type of component. There is therefore no valid comparison between this EIA recommended standard and the International Electrotechnical Commission recommendation. % These differences are well known to the US. Committee of Experts for the International Ele
7、ctrotechnical Commission Technical Committee 50 and resolution of these differences wiil be sought in future meetings of TC-50. Published by ELECTRONIC INDUSTRIES ASSOCIATION Engineering Department 2QQ1 Ep Street, N. W., Waehington, D. C. 20006 Q Electronic InduStriea Aeaoalaon 19 79 All righta rese
8、rved PRICE: $3.00 EIA 8b-13E 78 E 3234b00 0028574 2 E RS-186-13E Page 1 STANDARD TEST METHODS FOR PASSIVIE ELECTRONIC COMPONENT PARTS METIIOD 13 INSULATIQN RESISTANCE TEST (From EIA Standard RS-186-D and Standards Proposal No. 1271 formulated under the cognizance of the EL4 P-9 Committee on Test Mel
9、hods and Procedures.) INTRODUCTION This Test Method forms a part of the EIA Standard RS-186 which contains test guidance, definitions and standard test conditions. 1. PURPOSE This test is to measure the resistance offered by the insulating members of a component part to an impressed direct voltage t
10、ending to produce a leakage of current through or on the surface of these . members. A knowledge of insulation resistance is important, even when the values are comparatively e high, as these values may.be limiting factors in the design of high-impedance circuits. Low insulation resistance, by permi
11、tting the flow of large leakage currents, can.disturb the operation of circuits intended to be isolated, for example, by forming feedback loops. Excessive leakage currents can eventually lead to deterioration of the insulation by heating or direct-current electrolysis. Insulation- resistance measure
12、ments should not be considered the equivalent of dielectric withstanding voltage or electric breakdown tests. A clean, dry insulation may have a high insulation resistance, and yet possess a mechanical fault that would cause failure in the dielectiic withstanding voltage test. Con- versely, a dirty,
13、 deteriorated insulation with low insulation resistance might not break down under a high potential. Since insulating members composed of different materials or combinations of materials may have inherently different insulation resistance, the numerical value of measured insula- tion resistance cann
14、ot properly be taken as a direct measure of the degree of cleanliness or absence of deterioration. The test is especially helpful in determining the extent to which insulating proper- ties are affected be deteriorative influences, such as heat, moisture, dirt, oxidation, or loss of volatile material
15、s. 2. PRECAUTIONS 2.1 Hazardous Voltages - Persons performing the test should bear in mind that the voltages used are dangerous, particularly since they will be direct current voltages. 2.2 Factors Affecting Measurements - Factors affecting insulation-resistance measurements include tem- I perature,
16、 humidity, residual charges, polarity in special cases, charging current or time constant of instrument and test voltage, previous conditioning, and duration of uninterrupted test voltage appli- cation (electrification time). In connection with this last-named factor, it is characteristic of certain
17、 component parts (for example, capacitors and cables) for the current to fall from an instantaneous high value to a steady lower value at a rate of decay which depends on such factors as time, test voltage, temperature, insulating materials, capacitance, and external circuit resistance. Consequently
18、, the measured insulation resistance will increase for an appreciable time as the test voltage is applied uninterruptedly. Because of this phenomenon, it may take many minutes to approach maximum insulation-resistance readings, but specifications usually require that readings be made after a specifi
19、ed EIA Lb-13E 78 m 3234b00 0028575 4 m Page 2, 2.3 2.4 2.5 3. 3.1 3.2 4. 5. 5.1 time, such as 1 cant test results in the following cases: 2 minutes, This shortens the testing time considerably while still permitting signifi- a, The insulation resistance is reasonably close to steady-state value, or
20、b. The current-versus-time-curve is known, or c. Suitable correction factors are applied to these measurements. For certain component parts, a steady state instrument reading may be obtained in a matter of seconds. Humidity - At room temperature, for room ambient measurements, the effects will usual
21、ly be small if the Relative Humidity is held between 30% and 60% RH. Between 60% and 80% RH, there will often be a noticeable effect. Maximum Testing Potential - Under no circumstances should the insulation-resistance measuring potential exceed the voltage rating of the insulation between the points
22、 of measurement. Repeated Testing - If insulation-resistance measurements are made before and after another test, both measurements should be made under the same conditions and preferably using the same apparatus. APPARATUS Insulation-resistance measurements shall be made with apparatus such as a me
23、gohm bridge, megohm- meter, insulation-resistance test set, etc., suitable for the characteristics of the component part to be measured. Allowable Error - Unless otherwise specified, the test apparatus error at the insulation resistance value to be measured shall not exceed lo%, for values up to 30
24、megohms per volt applied. Circuit Time Constant - The time constant of the measuring circuit, with the item being measured connected, shall not exceed 0.1 of the electrification time, For the standard 2 minute electrification time, the constant shall not exceed 12 seconds. PRECONDITIONING OF SPECIME
25、NS Specimens shall be preconditioned at standard atmospheric conditions* for 1 to 2 hours before measurements are made, unless otherwise specified in the governing test procedure or component part specification requirement, This preconditioning shall be superseded by any conditioning specified in a
26、governing test procedure and shall not be added to any such other conditioning. PROCEDURE Test Potential - Unless otherwise specified, the direct potential applied to the specimen shall be one of the following standard test potentials: 100 volts k 10%,500 volts f lo%, or 1,000 volts f 10% For manufa
27、cturers production testing, any voltage may be used provided it is equal to or greater than the minimum potential allowed by the applicable test condition. In case of any disagreement, referee tests shall be conducted at the specified standard test potential. Precision measurements under referee con
28、ditions shall be made under mutually agreed applied voltage tolerances. EIA LBb-13E 78 m 3234b00 002857b b m R$-186- 13E Page 3 5.2 5.3 5.4 5.5 5.6 6. 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 If more than one measurement is specified, subsequent measurements of insulation resistance shall be made using the s
29、ame polarity as the initial measurements. Measurement Accuracy - If actual measured values of insulation are required, the accuracy of the measurement shall be stated. Guard Circuit and Special Conditions - Proper guarding techniques shall be used to prevent erroneous reading due to leakage along un
30、desirable paths. Apparatus and as much of the connecting leads as possible should be at standard room conditions, unless otherwise specified. If special preparations or conditions, such as special test fixtures, connections, grounding, isolation, low atmospheric pressure, humidity, or immersion in w
31、ater are required, they shall be specified. Measurement Points - Insulation-resistance measurements shall be made between the mutually insu- lated points or between insulated points and ground, as specified. Environmental Conditions During Measurement - Specimens shall be at standard atmospheric con
32、di- tions” during the time of measurement, unless otherwise specified in the governing test procedure or the component part specification requirement. Electrification Time - If electrification time is a factor, the insulation-resistance measurements shall be made immediately after a 2 minute period
33、of uninterrupted test-voltage application, unless other- wise specified. However, if the instrument-reading indicates that an insulation resistance meets the specified limit, and is steady or increasing, the test may be terminated before the end of the specified period. If the relevant specification
34、 includes a limit on the charging current it may be necessary to increase the electrification time to comply with the requirements of 3.2, SUMMARY. The following details or options must be specified in the individual component standard: Nominal standard test potential to be used (or other potential
35、in special applications). 5.1. Special requirements for mounting, connection, or polarity. 5.3. Instantaneous charging current limit if required. Preconditioning requirements, if as-received condition, preconditioning of 4, and standard ambient conditions for measurement are not acceptable. The poin
36、t of measurements. 5.4. Electrification time, if other than 2 minutes. 5.6. Allowable test apparatus error at the insulation-resistance values required, if other than lo%, or if the insulation resistance value is above 30 megohms per volt applied. 3.1. Specify whether the test information shall show
37、: a. That the insulation resistance is above or below the specified limit, or b. That the actual insulation resistance is to be recorded. (In this latter case, indicate if the measurement accuracy is to be stated.) “See Page 2, Paragraph 5, RS-186-E, “General Instructions and Index of Tests”, STANDARD ATMOSPHERIC CONDITIONS ,
