1、ANSVEIA RS448-78 Appio?ed April6, 1978 EIA STANDARD STANDARD TEST METHODS FOR I ELECTROMECHANICAL SWITCHES MARCH 1978 Ehneedqg hprtmeat HltCTRONiC INDUSTRIES ASSOCIATION EIA 448 78 m 3234600 O069005 3 m ELA engineering standards are designeci to mrve the pubiic interat throu elimlnatfng mis- ment of
2、 products, and assistin the purchaser in selectin and obtaining w% minimum delay the clu r e any member or non-member of EIA from manufacturing or seliing products not codo such standards, nor shall the existence of such standards preclude their voluntary use by those o er than EIA members whether t
3、he standard is to be used either domestically or internationally. Recommended standards are adopted by EIA without regrird b whether or not their adoption may involve patents on articles, materiais, or processes. By such action, EiA does not wume any liability to any patent owner, nor does it wume a
4、ny obligation whatever to parties adopting the recommended standards. understandings between manufacturera and purchasers, facilitating interch ea $P iUty and improve- pro r product for his partic d ar need. Existence of su CR standards shall not in any respect pre- This Standard contains the major
5、technical contents of International Electrotechnicai Commission recommendation IEC 5 12, Basic Testing Procedures and Measuring Methods for Electromechanical Components for Electronic Fkpipment. It differs from IEC 512 in certain important respects as given in Appendix B hereto. These differenceshav
6、e been called to the attention of the U.S. Committee of Technical Experts for IEC Technical Committee TC48, and resolution of these differences wiil be solved in future meetings of TC48. Published by ELECTRQNIC INDUSTRIES ASSOCIATIION Engineering Department 2001 Eye Street, N. W., ?Vl contact force,
7、 shape, area, and condition (including relative cleanliness, smoothness, and hardness); current; open circuit voltage appearing at the contacts during interruption of current; temperature; and thermal conductivity of leads. These factors should be considered in the design of test jigs or clamps, and
8、 in performing switch resistance measurements. It is also important to keep the switch free from vibration and to prevent changes in normal contact force which might result from improper application of connections. Switch resistance values are influenced by factors such as resistivity of the surface
9、 2.3 Unless otherwise specified, the test current and open circuit test voltage shall be as specified below. A series resistor may be used provided the specified open circuit test voltage is not exceeded. 2.3.1 and test current shall be 100 milliamperes f 2 percent. Normal level: maximum open circui
10、t test voltage shall be 2 volts DC or 6 volts DC, 2.3.2 current shall be 10 milliamperes maximum. Millivolt level: maximum open circuit test voltage shall be 30 millivolts, and test 2.4 The number of activations to cleanse the contacts prior to measurement shall be as specified in the detail specifi
11、cation. 2.5 The number of test activations for measurement shall be one, unless otherwise specified in the detail specification. 3 RS-448 Page S 2.6 The number of measurements per test activation to be made on each contact shall be as specified in the detail specification. 3. SUMMARY The following d
12、etails must be specified on the detail specification: 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Method of connection (See 2.2). Number of activations prior to measurement (See 2.4). Normal or millivolt level (See 2.3). Open circuit test voltage (See 2.3.1). Number of test activations if other than as specified in
13、 2.5. Number of measurements per test activation (See 2.6). Maximum allowable resistance. EIA 448 78 W 3234600 0069032 O W RS-448 Page 6 METHOD 2 CAPACITANCE 1. PURPOSE The purpose of this test is to measure the capacitance of component parts. Preferred test frepuencies for this measurement are 60 H
14、z, 120 Hz, lkHz, lOOkHz, and 1 MHz. 2. PROCEDURE The capacitance of the specimen shall be measured at or referred to an ambient temperature of 25C with a capacitance bridge or other suitable method at the frequency specified. The inherent accuracy of the measurement will be 10.5 percent M.2 picofara
15、d unless otherwise specified. Suitable measurement technique shall be used to minimize errors due to the connections between the measuring apparatus and the specimen. The alternating-current (AC) voltage actually impressed across the specimen shall be as low as practicable. When a direct-current (DC
16、) polarizing voltage is required, it shall be as specified and shall exceed the peak AC voltage impressed across the specimen; however, the sum of the peak AC and the DC voltage shall not exceed the voltage rating of the specimen. 3. SUMMARY The following details must be specified in the individual
17、specification: A. Test frequency (See 2). B. Limit of accuracy, if other than that specified (See 2). C. Magnitude of polarizing voltage, if applicable (See 2). D. Switch Mounting: mounting plate, mounting screws. E. Points of measurement (connections to switch). F. Acceptable limits of capacitance.
18、 - I EIA q48 78 m 323V600 0069033 2 m METHOD 3 CHROMATICITY Under consideration. RS48 Page 7 -. - /e- I EIA 448 78 3234b00 ObOLY 4 1 RS-448 Page 8, METHOD 4 TR ANSMITTANCY Under consideration. I EIA 448 78 3234600 0069035 b M RS-448 Page 9 METHOD 5 STRENGTH OF MOUNTING MEANS 1. PURPOSE This test is
19、intended to evaluate the ability of a threaded bushing mounted switch to withstand a specified mounting torque. 2. PROCEDURE 2.1 The switch shall be mounted to a metal panel using normal mounting means and specified hardware. A torque of 15 pound-inches, or as specified in the detail specification,
20、shall be gradually applied to the mounting nut. Only one mounting nut shall be used in this test. 2.2 When the switch and/or associated mounting hardware incorporates a non-turn feature, the switch shall be mounted in a normal manner, with the mounting nut tightened with a torque of 5 oz.-in. maximu
21、m. A torque of 5 1b.-in., or as specified in the detail specification, shail then be applied to the mounted switch body. 3. MEASUREMENTS After the test the switch shall be examined for damage to the switch, mounting bushing, or their posi- tional locking means; loosening of parts; change in relative
22、 positions of parts; operating characteristics; or as specified in the detail specification. 4. SUMMARY The following details shall be specified in the detail specification: 4.1 Use of Procedure 2.1,2.2, or both. 4.2 Torque to be applied to the mounting nut if other than 15 pound-inches (See 2.1). 4
23、.3 Torque to be applied to the mounted switch body if other than 5 pound-inches (See 2.2). 4.4 Measurements and examinations to be made after test. RS448 Page 10 METHOD 6 TERMINAL TEMPERATURE RISE 1, PURPOSE This test is intended to evaluate the ability of a switch to carry its rated current without
24、 overheating. 2. PROCEDURE 2.1 The switch shall carry its maximum rated current continuously until constant temperatures are attained on the switch terminations. Unless the switch is provided with attached leads, connections to the switch shall be made with Type RFH-1, TF, RH, or f wire in accordanc
25、e with American National Standard Cl-1975 not less than one foot long and of the and b. The potential between live parts and conductive dead metal parts is to be the full test potential. The test results are not acceptable if the fuse mentioned above opens during test. 3.3 The number of poles under
26、test, the test current, the test voltage, the type of load per pole, and the wiring of the pales to be tested shall be as specified in the detail specification, 3.4 The wire size shall be in accordance with Table 4. The switches shall be mechanically operated for 50 cycles at a rate of not more than
27、 10 cycles per minute while making and breaking the required test current, The duty cycle shall be approximately 10% “on” and 90% “off”. The following details shall apply: TABLE 4 0-6 6.1-10 10,l-15 15.1-20 20.1-30 30.145 45.1-60 18 16 14 12 10 8 6 3.4.1 The sivitches shaU be connected to the requir
28、ed load and to a supply circuit, the voltage of which is,within 5% of the rated voltage of the switch. The capacity of the test circuit shall be such that the potential Qcross the load, as measured at or adjacent to the switch, will have the required value when the switch under teat is closed in the
29、 circuit with the required test current flowing. - - - EIA 448 78 m 323!IbOO 0069023 L m RS-448 Page 15 3.4.2 The switch shall be connected in the test circuit between the high side of the source and the load unless otherwise specified on the detail specification sheet. 3.4.3 In testing a switch, a
30、cycle shall be defined as specified in the detail specification, and return to original position. 3.4.4 Except for the manufacturers regular practice of lubricating switches as they are assembled, a switching mechanism shall not be adjusted, lubricated, or otherwise conditioned either before or duri
31、ng any of the tests. 4. MEASUREMENTS 4.1 At the completion of the test, measurements shall be made as specified in the detail specification. 5. SUMMARY The following details shall be specified in the detail specification. 5.1 Number of cycles of operation and definition of “cycle” (actuator travel,
32、positions through which it is moved, etc.) (see 3.4.3). 5.2 Power factor, and circuit frequency if other than specified in Paragraph 2. 5.3 Test voltage, test current, type of load per pole, and how loads are to be connected to each switch under test (see 3.3). 5.4 Rate of operation, if other than 1
33、0 cycles per minute maximum (see 3.4). 5.5 Measurements to be made to determine acceptability. 5.6 Measurement intervals. b. - EIA 448 78 m 3234b00 0069022 3 m SWITCH RS-448 Page 16 FULL LOAD CURRENT, AMPERES METHOD 8 RAT1 NG, HORSEPOWER ELECTRICAL ENDURANCE 125V 1, PURPOSE This test is intended to
34、demonstrate the ability of a switch to satisfactorily control its rated load(s) for its specified life. 2. TEST CONDITIONS 2.1 The switch shall be tested at its rated electrical load) and for the number of cycles specified in the detail specification sheet. 2.2 Switches previously tested for overloa
35、d as specified in Method 7 shall be endurance tested on the same set of contacts unless otherwise specified in the detailed specification. 2.3 Overload and endurance tests at the highest rated voltage may represent tests at a lower voltage of the same frequency if the volt-amperes at the high voltag
36、e is the same or larger than the volt-amperes at the lower voltage. (The temperature test is to be conducted at the highest ampere rating that the test represents). Switches for use in alternating current circuits shall be tested with an inductive load having a power factor of 0.75 to 0.80 when rate
37、d for inductive circuits, or a resistive load having a power factor of 0.98 to 1.00 when rated for resistive circuits only. Switches with direct current rating shall be tested with resistive loads. 2.4 Horsepower-rated switches: If a switch is rated in horsepower only, the endurance test current sha
38、ll be the appropriate value of full load current given in Table 1 or Table 2 as applicable. The power factor of the inductive load for an alternating current switch shall be 0.75 to 0.80. TABLE 1 TEST CURRENT FOR DC SWITCHES (HORSEPOWER RATED) 1/10 118 Il6 114 113 II2 314 1 1-112 2 2. o 2-2 2.4 3.0
39、3.8 5.4 7.4 9.6 13.2 17.0 25V 1 .o 1.1 1.2 1.5 1.8 2.7 3.7 4.8 6.6 8.5 EIA 448 78 i 3234600 00b9023 5 W RS-448 Page 17 TABLE 2 FULL-LOAD CURRENTS FOR A-C MOTORS RATED IN HORSEPOWER FULL-LOAD CURRENT, AMI 250 VOL :RES 24 SINGLE- PHASE 480 VOLTS 12( SINGLE- PHASE 3.0 3.8 4.4 5.8 7.2 9.8 13.8 16.0 20.0
40、 24.0 125 VOL TWO PHASE 1 HORSE- POWER THREE- PHASE TWO PHASE THREE- PHASE TWO PHASE THREE- PHAS E 1/10 118 116 1 I4 113 112 314 1 1-112 2 - - - - - 4.0 4.8 6.4 9.0 11.8 1.5 1.9 2.2 2.9 3.6 4.9 6.9 8.0 10.0 12.0 - - - - - 2.0 2.4 3.2 4.5 5.9 - - - - - 2.0 2.8 3.6 5.2 6.8 - - - - - 1 .o 1.2 1.6 2.3 3
41、.0 - - - - - 1.0 1.4 1.8 2.6 3.4 - - - - - 4.0 5.6 7.2 10.4 13.6 2.5 Different values of power factor, circuit frequency, and rate of operation may be used if specified in the detail specification. 2.6 Whenever tests are made with alternating current, the circuit frequency shall be the same as the r
42、ated frequency of the switch, except as noted in 2.7 or, if no frequency is specified, 60 hertz alternating current shail be used. 2.7 A switch rated at 50 hertz may be tested in a 60 hertz circuit provided the overload and endurance test currents are 120% of the current that would have been used in
43、 a 50 hertz circuit. 2.8 A switch intended for the control of tungsten filament lamps shall be operated for the number of cycles specified in the detailed specification making and breaking a circuit with a load of tungsten filament lamps or a load having equivalent circuit characteristics, and so ad
44、justed that the normal current flow is the rated current of the switch. The open circuit potential of the test circuit shall be 120 +. 5 volts, and the closed circuit potential at the load with normal current flowing shail be within 5% of the open circuit potential. Either a direct current or altern
45、ating current supply shall be used, as specified in the detail specification sheet. Lamps shall have a minimum off time of 55 seconds for cooling. 3. PROCEDURE 3.1 The switch shall be mounted by its normal mounting means. During the test, all metal parts of the frame and the enclosure that may be gr
46、ounded when installed under normal conditions of actual service or that are exposed to contact by the user shall be connected to ground or to a conductor of the test circuit. RS-448 Page 18 3.2 Dead metal parts are to be connected to the ground of the power source through a normal-blow- type fuse ra
47、ted at 5% or less of the resistive contact load, with a minimum rating of 100 milliamperes. The circuit is to be connected so that: a. On direct current the dead metal parts will be positive with respect to the nearest arcing point in the switch; and b. The potential between live parts and conductiv
48、e dead metal parts is to be the full test po tential. The test results are not acceptable if the fuse mentioned above opens during test. 3.3 The number of poles under test, the test current, the test voltage, the type of load per pole, and the wiring of the poles to be tested shall be as specified i
49、n the detail specification. 3.4 The wire size shall be in accordance with Table 3. The switches shall be mechanically operated for the number of cycles specified in the detail specification and at a rate of not more than 10 cycles per minute while making and breaking the required test current. The duty cycle shall be a minimum of 10% on. The following details shall apply. TABLE 3 WIRE SIZE, ELECTRICAL ENDURANCE TESTS I TEST CURRENT, AMPERES I WIRE SIZE, AVERAGE 0-6 6.1-10 1 O. 1 - 15 15.1-20 20.1-30 30.1-45 45.1-60 18 16 14 12 10 8 6 3.4.1 The s
