|
|
5.12 For heating appliances and combined appliances, when it is specified that the
6 V, ]4 O* T) y; ]! Nappliance has to operate at a power input multiplied by a factor, this applies only to heating8 T6 L1 E( L( p3 @# O
elements without appreciable positive temperature coefficient of resistance.
1 W r( b! J2 `. @, Q& sFor heating elements with appreciable positive temperature coefficient of resistance, other than
& b& I/ P3 d7 w6 n; nPTC heating elements, the supply voltage is determined by supplying the appliance at rated/ [; d, W5 m% V
voltage until the heating element reaches its operating temperature. The supply voltage is then
0 G7 Y- }% E9 n+ c; J: V, dCopyright International Electrotechnical Commission7 s$ o/ P! h q( z: ^
rapidly increased to the value necessary to give the power input required for the relevant test,& c! o! @9 V) E1 X2 A" [
this value of the supply voltage being maintained throughout the test.0 z' N' [4 G9 y! `
NOTE In general, the temperature coefficient is considered to be appreciable if, at rated voltage, the power input
- _. B# p( S4 Z3 M8 sof the appliance in cold condition differs by more than 25 % from the power input at operating temperature.0 T( o' R; {! ?' u9 V) ]2 ]
5.13 The tests for appliances with PTC heating elements and for heating appliances and
* v: P( |0 X9 }; icombined appliances where the heating elements are supplied via a switch mode power* c2 h6 ?1 M3 ~7 |9 B: E8 N2 q% ~& F
supply are carried out at a voltage corresponding to the specified power input.
' Y6 T+ j% t) ?) T, k4 C8 u# T3 d- CWhen a power input greater than the rated power input is specified, the factor for multiplying
9 J. ~( {6 ^( H, g' Othe voltage is equal to the square root of the factor for multiplying the power input. |
|
/2 
|关于安规|小黑屋|安规QQ群|Archiver|手机版|安规网
( 粤ICP13023453-10 ) 
窥视卡
雷达卡
发表于 2012-10-14 22:14
显身卡