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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:' i* A4 K! Y+ k' m, y
– motors that are used for air-handling only and where the air propelling component is' o) F2 }1 L: Q b
directly coupled to the motor shaft; and 7 P( \3 n" U1 ~' h
– shaded pole motors whose values of locked-rotor current and no-load current do not differ' y' D0 {) ~8 j% E8 e+ S: }
by more than 1 A and have a ratio of not more than 2/1. " j$ r; P9 J8 Q- B3 \7 R
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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:: K5 h0 q4 U2 v/ T
– a motor protected by inherent or external impedance is operated with its rotor locked for
( q# E. j- ]. @5 g2 k s8 j! [15 days except that testing may be discontinued when the windings of the motor, of either
- }/ @+ ~+ X5 M2 ~2 n. hthe open or totally enclosed type, reach a constant temperature, provided that the
/ [' l! v+ o- T z8 z4 K+ hconstant temperature is not more than that specified in 4.5.3, Table 4B for the insulation
: F# | J. T) f" tsystem used; 0 _9 y+ s/ v! e$ t7 ]+ Z, x
– a motor with an automatic reset protection device is cycled with its rotor locked for , u; H( q7 d% Z" u8 x
18 days;
( W' X5 e, R( O% B1 z) z& L– a motor with a manual reset protection device is cycled with its rotor locked for 60 cycles, 5 \. `# K+ L8 S) E* B% U! A% R6 A
the protection device being reset after each operation as soon as possible for it to remain
; }- O. C/ l. W1 Q8 ]- U* aclosed, but after not less than 30 s; 4 T0 x/ H* a4 W) S F; J4 J
– a motor with a non-resettable protection device is operated with its rotor locked until the ( Q3 ^# j$ }- O2 z% p: z
device operates.$ o# D( l; `' d% c7 Z( D; w8 U
1 \, _4 A( J0 y" 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; i& y& k P0 Q; ]
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
O% t. t0 k; Q( n3 J% T/ B度不大于4.5.3的表4B规定的温度,则试验可以结束! Z/ P0 y) `) o/ n' w( c
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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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