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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:" p( K! g1 t+ a# X' P! U
– motors that are used for air-handling only and where the air propelling component is
7 y) y2 T( I4 kdirectly coupled to the motor shaft; and 5 s. s, ]0 G* }1 g, H; [) a% k. T
– shaded pole motors whose values of locked-rotor current and no-load current do not differ1 {0 a1 n2 B: P+ `1 S8 K
by more than 1 A and have a ratio of not more than 2/1.
) M8 X/ y2 ?* W% |' q
$ i0 m% _+ A2 Y% H8 w& y6 {: x& W- @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:
' V0 p# t7 l! W– a motor protected by inherent or external impedance is operated with its rotor locked for % j! q2 B& j* `$ X" ?* ^
15 days except that testing may be discontinued when the windings of the motor, of either & t7 \& w: f* G- v8 T$ G Z& _
the open or totally enclosed type, reach a constant temperature, provided that the , p7 q! I! w( @1 L' L" q; ^0 N
constant temperature is not more than that specified in 4.5.3, Table 4B for the insulation 0 C/ A; B" Q( g3 L# g: N* {
system used; $ E7 \0 \0 x; Z+ t0 ~' `
– a motor with an automatic reset protection device is cycled with its rotor locked for * `$ Z5 f1 r3 F6 q% _2 D
18 days; % j5 S) F) C; l8 y, b$ E' ]+ u8 B: g* X
– a motor with a manual reset protection device is cycled with its rotor locked for 60 cycles,
' J1 w2 Z, | G. }0 K0 Rthe protection device being reset after each operation as soon as possible for it to remain 3 O r: X2 n* f, m5 w
closed, but after not less than 30 s; $ T) {5 e6 a f( ]1 Z' a
– a motor with a non-resettable protection device is operated with its rotor locked until the " g" K2 [' @6 r. e
device operates.
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* J- q* Z% g, I8 u# p1 K4 ^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
( J4 v+ {$ O! i- P) p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
' n) n5 |1 {9 o& y( k0 b% S2 ?度不大于4.5.3的表4B规定的温度,则试验可以结束! U; a+ _. I2 S) l+ ]9 }) G, B
: y5 d8 A# e5 }1 v; j# P! L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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