STANDARDIZATION RULES OF Till. A I i 



through ation. Where ihe value found to this way exceed* ooc 



megohm, it it usually sufficient. 



213 INSULATION Hi .ould. if potable. b made at the 

 ' iturc fur which the apparatus is designed. 



CTRIC STRRNCI It 

 (A) TKT Voi. i A 



214 l>ir. : he dielectric strength of an mtulating *ll. cwating 

 cover or path it mea>: -e voltage which must be applied to 



..r.ir: tc -!! et a !. .;u;. !.. '. ham .,. .. - 

 216 UN : i ... . TRST V The test voltage which 



should be a} insulation for commer- 



normal operating v c of the service in wh 



used, and the scve: i mechanical and elect r 



h it may be subjected. 1 .;c> and other con 



which arc re. <-d have been determined as reasonable and proper 



t:reat ma cases and are proposed for general adoption. 



;<ccific reasons make a mo : 



216 or APPAKATUS TO HE TESTED. Commercial tests shoul 

 be made with the completely assembled apparatus and no*. 



The apparatus should be in good condition and high- 

 voltage tests, unless otherwise specified, should be applied before the 

 machine is put into commercial service, and should not be applied when 

 the insulation resistance is low owing to dirt or moisture. High- voltage 

 should, in general, be made at the temperature assumed under nor- 

 mal operation. High-voltage tests considerably in excess of the normal 

 voltages 'ions are fulfilled are admissable 



on new machine** nless otherwise agreed tspon. high-voltage tests 



of a machine should be understood as being made at the factory. 



217 I'MIM* OF Arn ; ige should be sue- 



between each electric circuit and all other electric cir- 

 cuits including conducting material in the apparatus. 



218 The I'i test voltage is, in general, 

 immaterial within commercial ranges. When, however, the frequency has 

 an appreciable ef n alternating-current apparatus of high voltage 

 and considerable capacity, the rated frequency of the apparatus should 

 be used. 



219 TABLE OF '1 >LTAGES. The following voltages are recommended 

 for testing all apparatus, lines and cables, by a continued application 

 for one minute. The test should be with alternating voltage having a 



(or root mean square referred to a sine wave of voltage) 

 given in the table, and preferably for tests of alternating apparatus at 

 the normal frequency of the apparatus. 



lUud Terminal Volue o( lUtd Output. T*un* Votu* 



220 Not exceeding 400 . icr 10 kw 1.000 volts 



kw. and ..-.<- 1.500 

 400 and over, but less than 800 volts. . Under 10 kw 



and over 2.000 



MX) - 1.200 ' 3.500 



- 2,500 ~ H) 



2.500 ' * Any Double the normal rated 







221 ICxcBPTios. TtANSFORMiBS. Transformers having primary pressures 

 of from 560 to 5,000 volts, the secondaries of which at- 



nected to consumption circuits, should have a testing voltage of 10.000 

 volts, to be applied bctw. ry and secondary windings, and 



also between the primary winding and the core. 



222 KXCEFTION. FIELD ---sts for field windings should be 

 based on the rated voltage of the exciter and the rated output of the 

 machine of which the coils are a part. Field windings of synchronous 

 motors and converters, which are to be started by applying alter: 

 current to the armature when the field is not excited and when a high 

 voltage is induced in the field windings, should be tested at 5.000 volts. 



