第1个回答 2015-11-15
因为总开关断路器是380V的,而且功率太大,再加上没有分路断路器,所以电缆发热并烧毁电器断路器不跳闸。
如何选择断路器这是一个专业的技术问题。简要的说可以从以下6点来选择:
1、首先根据额定电压选,额定电压要一致。
2、断路器的额定电流要大于等于所用电路的额定电流。
3、断路器的额定开断电流要大于等于所用电路的短路电流。
4、根据环境条件选,如海拔、温度、湿度,选择符合要求的断路器。
5、根据品牌选质量、性价比较高的断路器。
6、对特殊开断情况,进行校验断路器。然而不同的负载应选用不同类型的断路器,最常见的负载有配电线路、电动机和家用与类似家用(照明、家用电器等)三大类。以此相对应的便有配电保护型、电动机保护型和家用及类似家用保护型的断路器。这三类断路器的保护性质和保护特性是不相同的。对配电型断路器而言,它有A类和B类之分:A类为非选择型,B类为选择型。所谓选择型是指断路器。
第3个回答 2009-06-12
断路器的电流量程过大,一般所有用电器的电流比段路器的电流捎大点,过大了 不起作用,烧毁电线;过小了,老跳闸.......电线也要选好.....................................本回答被提问者采纳
第4个回答 2009-06-12
断路器选的过大,一般选择线路保护都是----- I电缆 〉I断路器 〉I设备
B.3.1 In all cases, the following relationships shall exist:
Ib < In
Ib < Iz
where
In is the nominal current or current setting, in amperes, of the over current protective device;
Iz is the effective current carrying capacity, in amperes, of a cable for continuous service
under the particular installation conditions concerned.
B.3.2 Where the over current protective device is intended to provide overload protection, the
following relationships shall exist:
Ib < In < Iz
I2 < 1,45 Iz
where I2 is the minimum current, in amperes, that when maintained for 1 h will cause the
protective device to open the circuit
In is the nominal current or current setting, in amperes, of the over current protective device;
Iz is the effective current carrying capacity, in amperes, of a cable for continuous service
under the particular installation conditions concerned.
Ib is the steady state current in amperes; (From IEC60204-32)