Air circuit breaker Selection Maintenance

Selection

AC contactor ① Press contactor control objects, the number of operations and the use of categories to select the appropriate category of contacts. ② by using the position CNC Electric‍ of the line of rated voltage selection.

③ Press the load capacity options contactor main contacts rated current.

④ For the attraction coil voltage levels and current type of control power requirements should be considered.

⑤ capacity options for auxiliary contacts, according to the quantity required and interlock loop connected to the contacts consider breaking current size.

⑥ for making and breaking contact with the capacity issues, the choice should pay attention to some of the load using the categories, such as capacitors, tungsten and other lighting device air circuit breaker‍, when connected to the current value of its large, on-off time is longer, the choice should be left margin.

⑦ for contactor electrical life and mechanical life issues, from the known average number of operations per hour and the life of the machine age, calculate the required electrical life, circuit breakers‍ if it can not meet the requirements should be derated.

⑧ selection should consider the environmental temperature, humidity, vibration using the workplace, dust, chemical corrosion, etc., should be the appropriate choice of different types of contacts environment.

⑨ lighting device is suitable for contacts, should also consider the type of lighting, the starting current size, duration and long-term work starting current, contact the current selection of electrical equipment should not exceed 90% (line) of the rated current. For tungsten and capacitive compensation lighting device, should consider making current value.

⑩ design should be considered a secondary device movement consistency.

Maintain

① operation inspection items: 1) whether the load current through within the contactor ratings in;

2) contactor switching signal indication is consistent with the state of the circuit;

3) Run the sound is normal, whether the issue due electri calmete‍ to poor contact discharge sound;

4) whether the electromagnetic coil overheating, short-circuit ring electromagnet without exception.

5) interrupter cover loose and damage;

6) whether the burning auxiliary contact situation;

7) transmission parts without damage;

8) whether the unfavorable factors in the operating environment to run, such as excessive vibration, poor ventilation, such as excessive dust.

② Maintenance:

When electrical equipment maintenance work should be a contactor and maintenance work.

1) External maintenance:

. a sweeping external dust;

. b Check all fasteners are loose, especially the mcb circuit breaker‍ conductor connecting part, to prevent contact with loose and fever;