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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:' e4 W9 d/ {* S; Q1 g- S
– motors that are used for air-handling only and where the air propelling component is7 k% R$ w. M8 P' b0 ^% ?
directly coupled to the motor shaft; and
5 z% k) a/ o! J6 I7 D; S– shaded pole motors whose values of locked-rotor current and no-load current do not differ. K& m, W. w0 L/ \# p% n
by more than 1 A and have a ratio of not more than 2/1. " q M: {5 y" F7 {/ K# p: `
4 V; ^ V4 V, g9 y
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:! q9 o4 j' |8 q/ d
– a motor protected by inherent or external impedance is operated with its rotor locked for
4 W" Y- D" m! C# O0 _' o15 days except that testing may be discontinued when the windings of the motor, of either
4 @; S6 L. d. }4 f9 lthe open or totally enclosed type, reach a constant temperature, provided that the
# N! ]5 ?; x' s2 l/ kconstant temperature is not more than that specified in 4.5.3, Table 4B for the insulation
$ H% m% e$ U& Y; F j6 y5 Jsystem used;
/ T$ B6 P7 C7 Z; m- b– a motor with an automatic reset protection device is cycled with its rotor locked for
, k$ O, A* ?4 Z: a& B; \' n18 days; ' h3 l3 D7 j' [! U
– a motor with a manual reset protection device is cycled with its rotor locked for 60 cycles, 9 w% c6 b t4 X9 U& }: U) c
the protection device being reset after each operation as soon as possible for it to remain
7 F, k& f! q( ]* v4 m8 _( J. L& Pclosed, but after not less than 30 s; $ E, n: ]$ s: |$ T2 C
– a motor with a non-resettable protection device is operated with its rotor locked until the
, T+ D: W' |( |, }device operates.9 z5 t! K/ t* G* f7 I( I
' ` L% W1 V3 p* T( R! F
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
9 _% m$ { `- q4 k7 b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( Z# O6 Q, P4 S% U
度不大于4.5.3的表4B规定的温度,则试验可以结束
, V& q! g; H- k0 V! n1 Z; |6 v' u0 R* }1 C* A0 l, B, V
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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