已知380V三相电机容量，热过载继电器，寻求它的额定电流和当前设置的元素。电机过载保护器，热继电器，热元件。公式：数的两倍半的电流容量。数的两倍千瓦调整。
Known 380V three-phase motor capacity, thermal overload relay, seeking its rated current and current setting elements. Motor overload protector, thermal relay and heat element. Formula: the capacity of two and a half of the number of current. The number of two times the kilowatt adjustment.
说明：（1）易于电机起动器过载或严重，因为发射条件，可能无法启动，或需要以限制起动时间应装有过载保护。长期无人值守运行电机或电机3KW以上，但也应安装过载保护。过载保护装置一般采用热继电器或断路器的延时过电流脱扣器。目前，中国生产的热继电器适用于轻载起动，长期工作或间断长期电动机过载保护。 （2）热继电器过载保护装置，结构原理都非常简单，但非常讲究转让热敏元件，如果你有一个大的选举提出了水平下限，往往造成电机偷停，影响生产，增加了维修工作。如果选定的电平小，只能调谐到更高的限制，往往不操作时，在电动机过载，甚至烧毁电机。 （3）选择正确的计数，380V三相电机过载保护热继电器。仍然需要找出同型号的热继电器可配备不同的额定电流的热元件。加热元件设置电流按千瓦调整数的两倍：加热元件额定的电流容量在2号和半计数选举;热继电器的型号规格，即其额定电流值应大于或等于额定电流加热元件值。
Description: (1) easy motor starter is easy to overload or serious, because the launch condition, may not start, or need to limit start time should be equipped with overload protection. Long term unattended operation of motor or motor is more than 3KW, but overload protection shall also be installed. Overload protection devices usually use thermal overload or circuit breaker's delayed over current release. At present, the thermal relay made in China is suitable for starting with light load, and it has long term working or intermittent long term motor overload protection. (2) the thermal relay overload protection device, the structure principle is very simple, but very particular about transfer heat sensitive element, if you have a big election put forward the level lower limit, often cause the motor to steal, affect production, increase the maintenance work. If the selected level is small, it can only be tuned to a higher limit. It often does not operate when the motor is overloaded or even burned. (3) choose the correct counting, 380V three phase motor overload protection thermal relay. It is still necessary to find out the same type of thermal relay which can be equipped with different rated current heat elements. The heating element is set up to two times the number of kilowatt hour adjustment: the rated current capacity of the heating element is elected at 2 and half count; the model specification of the thermal relay, that is, the rated current value should be greater than or equal to the rated current heating element value.
2。已知380V三相电动机容量。查找其远程控制交流接触器额定电流水平。
2. The capacity of the 380V three-phase motor is known. Find the remote control AC contactor rated current level.
公式：远程控制电机接触器，双级能力;频繁启动倒车，L A级的基础设施。
Formula: remote control motor contactor, two-level capability, frequent start reversing, L a level infrastructure.
注：目前，常用的交流接触器CJ10，CJ12，CJ20系列，更适合于一般三相电机启动控制。
Note: at present, the commonly used AC contactors CJ10, CJ12 and CJ20 series are more suitable for starting control of general three phase motors.
3。已知笼型电动机容量。计算其控制断路器的脱扣整定电流。
3. The capacity of the cage motor is known. Calculate the tripping current of the circuit breaker.
口诀：断路器跳闸，设置时间：瞬时的电流容量一般为20小电机24：延时脱扣三倍半，整个热释放两次。
Pithy formula: circuit breaker tripping and setting time: the instantaneous current capacity is generally 20 small motor 24: the time trip is three times and a half, the whole heat release is two times.
说明：（1）断路器脱扣整定电流值电工经常遇到的问题，给出的公式，整定电流值和控制笼型电动机容量千瓦数的倍数关系。 （2）延时脱扣三倍半，整个热释放说两次，过载自动保护断路器延时脱扣其当前的设置可以控制电机额定电流的1.7倍选择，或3.5倍的数千瓦的选择。热脱扣电流设定，应等于或稍微大于电机的额定电流，在2倍的数量选择的马达容量千瓦。
Description: (1) the problems that the electric circuit breaker often meets, the formula given, the set current value and the multiple relation of the capacity of the cage motor. (2) time delay three times half, the whole heat release said two times, overload automatic protection circuit breaker delayed release of its current setting can control the motor rated current of 1.7 times the choice, or 3.5 times the number of kilowatts of the choice. The heat release current setting should be equal to or slightly larger than the rated current of the motor, and the capacity of the motor is 2 times the kilowatt.