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交流风扇必须满足附录B中的B4(过载运转试验)和B5(堵转试验)要求。除非以下情况,可以不用做B4试验:
, M4 i6 X) Y5 `$ d& _# j( n– motors that are used for air-handling only and where the air propelling component is! [1 h* V. B2 \% V% I% E$ F
directly coupled to the motor shaft; and
5 }$ L% u4 R' ?; F, ^5 J– shaded pole motors whose values of locked-rotor current and no-load current do not differ
! G, Z2 D" t* A4 N1 Dby more than 1 A and have a ratio of not more than 2/1.
P; y1 r: W% f" V9 D; y3 N5 s% s% W* ^5 D" m5 z
对于温升限制,标准要求B4试验和B5试验电动机绕组分别不超过表格B2和B1的要求。而堵转的试验时间是根据电动机的保护方式来选择的:
- ?( F8 i: M4 O" P– a motor protected by inherent or external impedance is operated with its rotor locked for + Z0 R2 U7 ]7 T
15 days except that testing may be discontinued when the windings of the motor, of either 3 N/ M# @8 U5 Z# y
the open or totally enclosed type, reach a constant temperature, provided that the ! I6 C$ Z5 F* a2 p2 X3 F/ \' V- S
constant temperature is not more than that specified in 4.5.3, Table 4B for the insulation
2 r' |; {+ |- [4 a7 ~0 @3 ^" gsystem used; 1 B5 ?" k" Z5 P; i' [1 E
– a motor with an automatic reset protection device is cycled with its rotor locked for
1 d% L ?4 L' ^$ R4 C18 days;
4 Q1 c( ] Q. J' R1 r( L9 q+ l- ?– a motor with a manual reset protection device is cycled with its rotor locked for 60 cycles,
1 b: X" g2 y* y" J! jthe protection device being reset after each operation as soon as possible for it to remain 4 L% d& N. f3 {$ @, D7 ^ g ~
closed, but after not less than 30 s; C3 Y( Y+ |* S i, {2 i5 O0 |+ V' ], M
– a motor with a non-resettable protection device is operated with its rotor locked until the 7 I5 v" [& [, M# e. ]0 t; p
device operates.; b7 F* T8 N6 u: y2 y& M
7 {7 H9 \# G6 e& h7 U6 Q2 u对于情况一,若固有阻抗或外部阻抗保护的电动机需要堵转方式工作15d,但对开启式或全封闭式的: \$ c" V" G5 c
电动机,当其绕组温度达到稳定时,就所采用的绝缘结构而言,如果该电动机的稳定温' U& Y0 r# d3 B5 {5 j1 b
度不大于4.5.3的表4B规定的温度,则试验可以结束
$ u# c0 O6 Q" N8 @% O0 ~9 k, J0 w
. o0 X0 Y3 ]( Z3 i( Q! [+ U, {" e" n0 P' \一切都还需要LZ对电动机的保护方式进行判断先 |
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