Automatic switch release setting current selection of the mouth - News - Global IC Trade Starts Here Free Join

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

Photocoupler

1. Use the motor's capacity (kilowatt) or transformer capacity (kVA) to directly determine the magnitude of the trip unit's rated current (A)
2. Mouth:
Motor instantaneous, kW 20 times transformer instantaneous, kVA 3 times thermal trip, according to rating
3. Description: The automatic switch is commonly used on the line that supplies power to the squirrel cage motor for the switch that is not operated frequently.
If the operation is frequent, a series of contactors can be added to operate. The automatic switch can be used for short-circuit protection by the electromagnetic release (momentary action), and the thermal release (or time delay release) is used for overload protection.
1 This sentence refers to the automatic switch that controls a squirrel-cage motor (three-phase 380 volts). The instantaneous current setting current of the electromagnetic trip unit can be selected as “20 times the kilowatts”. For example: 10 kW motor, automatic switching electromagnetic tripper instantaneous action setting current, 200 amps (1O × 20)
Some small-capacity motors have a large starting current. Sometimes, the instantaneous current setting current is selected according to "2 kW", and the starting current cannot be avoided. At this time, it is allowed to be larger. However, it is better to not exceed 20%.
2 This sentence refers to the automatic switch used as the main switch after the distribution transformer. The electromagnetic tripping device instantaneously sets the current (A), which can be pressed by "kV"
3 times "selection. For example: 500 kVA transformer, the automatic switching electromagnetic tripping device as the main switch sets the instantaneous current to 1500 amps (500 × 3).
3 For the overload protection of the above motor or transformer, the setting current of the thermal trip or the time delay overcurrent release can be selected according to the rated current of the motor or transformer. For example, a 10 kW motor has a set current of 20 amps; a 40 kW motor has a set current of 80 amps. For example, a 500 kVA transformer has a set current of 750 amps. When making a specific choice, it is also allowed to be slightly larger. However, it is better to not exceed 20%.