|
|
5.12 For heating appliances and combined appliances, when it is specified that the
x; ]+ @7 x& ]appliance has to operate at a power input multiplied by a factor, this applies only to heating
& W1 P% E5 s$ r R* r) l" Yelements without appreciable positive temperature coefficient of resistance.
' `. { {- l& [+ kFor heating elements with appreciable positive temperature coefficient of resistance, other than- D. q( { S! v6 n3 s! E; j
PTC heating elements, the supply voltage is determined by supplying the appliance at rated' Z! ]0 i8 r7 ` i4 L% r
voltage until the heating element reaches its operating temperature. The supply voltage is then
, X8 e: B0 W2 C$ [Copyright International Electrotechnical Commission
7 _1 X+ s( X3 _$ X0 ^rapidly increased to the value necessary to give the power input required for the relevant test,) |* r4 \- e9 p3 c) B7 b! ~
this value of the supply voltage being maintained throughout the test.* P8 Z$ _3 S% \4 _
NOTE In general, the temperature coefficient is considered to be appreciable if, at rated voltage, the power input
2 @( I4 B x' N& y% v% T- jof the appliance in cold condition differs by more than 25 % from the power input at operating temperature. }6 \$ L' z% e/ x
5.13 The tests for appliances with PTC heating elements and for heating appliances and( \4 f5 R/ @6 N8 u6 e5 f, ^. E) O
combined appliances where the heating elements are supplied via a switch mode power
0 _7 E# [* x6 v) T5 {, [supply are carried out at a voltage corresponding to the specified power input.
9 A' b: ^9 x0 Y8 J3 B2 y- j0 \+ xWhen a power input greater than the rated power input is specified, the factor for multiplying: e+ \+ y* Q+ C
the voltage is equal to the square root of the factor for multiplying the power input. |
|
|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