1. Auxiliary contact: the contact mechanically linked with the main circuit of the circuit breaker and the closing mechanism is mainly used for the display of the circuit breaker and the closing status, and is connected to the control circuit of the circuit breaker through the opening and closing of the circuit breaker to control or interlock its related electrical appliances. For example, it outputs signals to traffic lights, relays, etc. The additional current of 100A for the shell frame level of the molded case circuit breaker is a single break conversion contact, and 225A and above is a bridge contact structure, and the heating current is 3A; The additional current of 400A and above in the shell frame level can be installed with two normally open and two normally closed, and the heating current is 6A. The number of operation functions is the same as the total number of operation functions of the circuit breaker.
2. Alarm contact: the alarm contact used for circuit breaker accidents, and this contact only acts when the circuit breaker trips and breaks, mainly used for the load of the circuit breaker to overload, short circuit or undervoltage and other faults and trips freely, the alarm contact is converted from the original normally open orientation to the closed position, and the indicator light or electric bell and buzzer in the auxiliary line are turned on to show or remind the circuit breaker of the fault tripping status. Because the probability of the circuit breaker tripping freely due to load failure is not too much, the life of the alarm contact is 1/10 of the life of the circuit breaker. The operating current of the alarm contact generally does not exceed 1A.
3. Shunt excitation tripper: Shunt tripper is a kind of tripper encouraged by a voltage source, and its voltage has nothing to do with the main circuit voltage. The shunt trip is an accessory for long-distance operation and opening. When the supply voltage is equal to any voltage between 70% and 110% of the additional control supply voltage, the circuit breaker can be reliably disconnected. The shunt tripper is a short-term operation system, and the coil energizing time generally cannot exceed 1S, otherwise the wire will be incinerated. In order to avoid coil incineration, the molded case circuit breaker is connected in series with a micro switch in the shunt trip coil, when the shunt tripper is engaged by the armature, the micro switch is converted from normally closed to normally open, because the control line of the power supply of the shunt tripper is blocked, even if the button is held down artificially, the shunt coil will not be energized again, which avoids the occurrence of coil burning. When the circuit breaker is re-closed, the micro switch is back in the normally closed position.
4. Under-voltage tripper: The under-voltage tripper is a kind of tripper that makes the circuit breaker have a delay or no delay when its terminal voltage drops to a specified range, and when the power supply voltage drops (or even slowly drops) to the range of 70% to 35% of the additional operating voltage, the under-voltage tripper should operate, and the under-voltage tripper should be able to avoid the circuit breaker closing when the power supply voltage is equal to 35% of the additional operating voltage of the tripper; When the supply voltage is equal to or greater than 85% of the additional operating voltage of the undervoltage tripper, the circuit breaker should be able to be securely closed under hot conditions. Therefore, when the power supply voltage in the protected circuit produces a certain voltage drop, the circuit breaker can be automatically disconnected to block the power supply, so that the load electrical appliances or electrical equipment below the circuit breaker are protected from damage by the undervoltage. When in use, the under-voltage tripper coil is connected to the power supply side of the circuit breaker, and the circuit breaker is closed only after the under-voltage tripper is energized.
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1. The power value of the inverter is the most suitable for the power value of the motor, so as to facilitate the operation of the inverter at a high power value.
2. When the power classification of the inverter is not the same as the power classification of the motor, the power of the inverter should be as much as possible.
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Introduction to the output frequency of the inverter - LS power generation
1. Maximum frequency fmax, reference frequency fN and reference voltage UN
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