RATING OP ELECTRICAL M U HISERY 45 



it is recommended that the bulb be covered with tinfoil and every pre- 

 caution taken to prevent loss of beat. 



The temperature allowed depends on the character 

 of the in 



The temperature ! 



paper, and itt preparations, linen, or similar materials are used solely 

 as vehicles for insulation varnishes, or enamels, capable of continuously 

 >g temperatures above 125 def . cent. Machines in which such 

 materials are employed are dealt with separate 



A much higher tcmjx-ruiure rise than that specified on PA, 

 may be permitted in machines in w is secured by meant 



of special materials designed to resist high temperatures, but the amount 

 of permit Must depend on the properties of the 



insulating materials and the method of construction and most be settled 

 specially for each clas* 



SWEDEN : out as nearly as possible under 



ordinary working conditions. 



.<rnp.-r.i-ur. allowed must not be such as to 

 be detrimental to the insulation under ordinary working conditions. 



An overload may be a; horten the duration of the test. 



BELGIUM. By increase in resistance, if this method is practicable. 

 Otherwise by means of thermometers. 



PRANCE. Temperatures ascertained by means of thermometers, 

 placed in the hottest pan accessible; nevertheless, in the case of 



and all stationary windings, the temperature may be 

 by increase in resistance. 



GBK ng coils and stationary windings by increase in 



resistance, other parts by thermomf 



GREAT BRITAIN. Stationary windings by increase in resistance. 

 Moving coils by increase in resistance, if possible, otherwise by ther- 

 mometer or thermo-couple. Commutators, brushes, bearings by ther- 

 mometer. 



SWEDEN. Windings by increase in resistance, if possible, otherwise 

 by thermometer. Other parts by thermometer. 



i ED STATES. By thermometer. Conductors by rise in resistance, 

 when possible. 



Duration of Test 



Continuous service. A period of sufficient duration to attain a prac- 

 tically constant temperature: ordinarily 5 hours up to 20 kilowatts. 8 

 hours above 20 kilowatts. 



Intermittent servic*. One hour. 



Momentary tervice. The number of hours indicated on the name-plate. 



PRANCE. 



Continuous working. \ period sufficiently long to attain a prac 1 

 constant temperature. ',S 



Intermittent servtte. One ! 



Tb* periods art tivm. to * t*ocr*l m*aor. by Uw foOowtaf labto: 



K m Volti X Ampcr*. 



K ' Rrr.prr : 



10... 2 hour. 



10-30.. m 



TUO-l.OOO . 



100-200.. i.ooo-i.aoo . 10 



Abor. l.io <tettte*tk <rf UM 



