|
|
5.12 For heating appliances and combined appliances, when it is specified that the
! N1 Q8 |3 X% }4 ]' W M5 n0 ?3 vappliance has to operate at a power input multiplied by a factor, this applies only to heating
# P& I2 U3 X3 M4 {6 X- I5 I# }elements without appreciable positive temperature coefficient of resistance.7 y! b: ]: M# {$ U4 C* c- u
For heating elements with appreciable positive temperature coefficient of resistance, other than' x% I! U( w) ?7 y
PTC heating elements, the supply voltage is determined by supplying the appliance at rated
s* g. S: A( P9 h5 fvoltage until the heating element reaches its operating temperature. The supply voltage is then
& H7 _ ]3 I6 `3 @7 zCopyright International Electrotechnical Commission6 c. s) D0 V; w
rapidly increased to the value necessary to give the power input required for the relevant test,
0 j3 R7 [, `& o* ^' r* Mthis value of the supply voltage being maintained throughout the test.
& e9 B: `7 P; }! _$ c2 PNOTE In general, the temperature coefficient is considered to be appreciable if, at rated voltage, the power input
% l4 i; f) X4 O2 {& uof the appliance in cold condition differs by more than 25 % from the power input at operating temperature.
4 k. Q7 a$ a+ O! c9 x5.13 The tests for appliances with PTC heating elements and for heating appliances and
3 o* U1 l/ b* k8 Ucombined appliances where the heating elements are supplied via a switch mode power( k3 x( j2 w B5 \1 m
supply are carried out at a voltage corresponding to the specified power input.
. k3 U6 ?& H" P/ VWhen a power input greater than the rated power input is specified, the factor for multiplying: h3 i1 w1 |- I
the voltage is equal to the square root of the factor for multiplying the power input. |
|
/1 
|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