How to choose a DC screen outlet circuit breaker Can you give an example?

There are two main uses of DC screen outlet circuit breaker, one is to control the power supply, and the other is to close the power supply. When choosing, select the capacity of the closing circuit breaker, there is this provision in the power standard: generally take the multiple of the closing current, such as the circuit breaker of the electromagnetic operating mechanism, the closing current is 100A (there are also 200A), then the capacity of the DC circuit breaker is 30A, close to the specification of 32A (200A is 63A).

The selection of the control switch is generally two levels lower than the closing switch, if the female switch is selected 32A, the female control switch is selected 20A.

Now there are few electromagnetic operating mechanisms for high-voltage circuit breakers, basically spring operating mechanisms, the closing current has been greatly reduced, and the DC coupling is only for the energy storage motor in actual use, and the motor energy storage current is only 2A. Therefore, many DC screens on the female switch are generally taken 16A, and the female control switch is 10A, and some DC screens simply do not divide and close, control the female, and all switches are 10A, 16A, or 20A.

The DC screen outlet switch is generally used with a fuse, the outlet switch is equivalent to a "load switch", and the short-circuit protection is undertaken by the fuse. Therefore, the rated current of this switch (generally with air switch) as long as it is greater than the total load current and leave a proper margin for your reference.

Practice has proved that the circuit breaker and contactor are selected for the control switch, and the isolation switch is better for the capacitor switch. The fuse switch is of poor quality.

The teacher knows that the closing current is 100A, according to what formula to calculate the DC circuit breaker 30A, and then choose 32A, 200A, and 63A?

Because the shell of the circuit breaker dies when the current dies, 25A, 32A, 63A,,, not as much as you want.

The battery switch is faulty, indicating that the switch on the Tianchi circuit is tripped! Re-turn the battery circuit switch and you're done!

The problem of the number of corrupt officials is not the same as the problem of the number of people, ordinary people must be 1 + 1 = 2, and 1 + 1 = 10 or 100 or 1000 or 1000 or 10000Because they have a lot of energy. Two village-level officials may be equivalent to 10 explosives packets, and two provincial-level officials may be equivalent to 10,000 explosives packets.

That's the situation, that's the problem.

1 The battery switch trips or disconnects or the battery blows the signal.

Most of the corrupt officials are from elite backgrounds, their brains are full of wisdom, their eyeballs are full of gold and silver, their foul mouths are full of rotten meat, and their dog's ears are full of jewels, and their hearts are thinking of fleeing.

It refers to the switch of the light on the DC screen, which is generally a travel switch.

The high-frequency switching power supply cabinet is a kind of high-frequency power supply produced in the past, similar to the current switching power supply, and the DC screen is a cabinet that has rectifier and voltage stabilization and is equipped with a battery, and can provide DC operation power supply with or without mains.

The DC panel provides power for the control load and power load, as well as the DC accident lighting load, etc., and is the basis for the control and protection of the contemporary power system. The DC panel is composed of an AC distribution unit, a charging module unit, a step-down silicon chain unit, a DC feed unit, a distribution monitoring unit, a monitoring module unit and an insulation monitoring unit.

The high-frequency switching power supply refers to a separate AC to DC module, which is the DC power supply of the DC panel. The high-frequency switching power supply plus the feeder output and other monitoring units can form a DC screen.

DC panels also belong to high-frequency switching power supplies.

This is a very traditional division, the early closing circuit is dedicated to the circuit breaker operation opening and closing operation power supply, the output current is large, the voltage is high, the control loop is to protect and signal and instrument power supply The relative power requirements are small, the current circuit breaker closing current is very small, the DC screen is generally set up with a control loop, and the closing circuit is basically not used.

The closing circuit is to provide DC power supply for the closing operation of the circuit breaker of the high-voltage complete set of equipment, and the closing circuit is connected in parallel with the battery circuit, and the output current is large, so it provides DC power supply for the closing operation of the circuit breaker.

The control loop is to provide DC power supply for high-voltage complete sets of equipment, signal equipment, protection, automatic devices, etc.!

The output current of the control loop is not as large as the closing loop, but the output voltage is 220V plus or minus will not exceed 7V, and the voltage is relatively stable, so it provides DC power supply for signal equipment, protection, automatic devices, etc.!

You mean the AC input switch, if so, it definitely doesn't work, because the charging module in the DC screen is generally a three-phase input and there is no neutral line.

From Three Rivers Probiotic Electronics.

It's a bit hard to say, and the specific phenomenon may not be the only one you're talking about.

I've seen this phenomenon once, it may be that the two groups of DC control are mixed together, and it may also be mixed into the AC, you can check it, try to disconnect the second group of control and then close it to see if there is still this phenomenon, if there is still to shake the insulation to find, if not, congratulations on finding it slowly. The place where it can be mixed is generally at the place where the auxiliary contact is located at the switch position. (This explanation applies to general technical water products) high water products are only for reference, and beginners in water products, there are many mistakes and cannot be judged.

It is recommended to check the energy storage circuit and the auxiliary contacts of the switch to see if there is any grounding phenomenon.

What kind of operation is carried out after the brake is closed, it is necessary to analyze it specifically.

The light plate is on, or the police are called.

The parameters required for circuit breaker selection are mainly as follows:

1. Rated current.

2. Rated voltage.

3. Load situation (such as: ordinary power distribution protection, motor protection, long cable protection, etc., household power distribution protection is the majority).

4. Circuit breaker progression.

5. The maximum short-circuit current that may occur in the circuit (this parameter is used to select the breaking capacity of the circuit breaker, which is mostly estimated or selected according to convention).

6. What are the required protection functions?

1.Calculate the calculated current of the circuit first, and the rated current of the circuit breaker should be greater than or equal to the calculated current of the line. In this way, it can be determined whether the circuit breaker is molded or micro-broken, etc.

Generally, the micro-fracture is less than or equal to 63a, and the plastic shell is less than 1600a. Values may vary by manufacturer.

2.The short-circuit segmentation capacity of the circuit breaker is greater than the short-circuit current of the system.

3. Determine the purpose and protection of the circuit breaker you need, choose the motor for the motor circuit, and choose the single magnetic protection if it is a fire power circuit. Electronic without overload protection. These are the product selection manuals given by the manufacturer, which are very detailed.

Answer the question of the choice of circuit breaker for power distribution. Circuit breakers for power distribution are generally circuit breakers used in low-voltage power grids specifically for distributing electric energy, including power supply main circuit breakers and load branch circuit breakers. When selecting this type of circuit breaker, special attention should be paid to the following selection principles:

1) The allowable current carrying capacity of the line is not less than the setting value of the long-delay action current of the circuit breaker. In the case of wires and cables, the long-delay action current setting value of the circuit breaker can be 80% of the allowable current carrying capacity of the wire and cable. 2) The starting time of the motor with the largest starting current in the line is not more than 3 times the return time of the setting value of the long delay action current.

3) Instantaneous current setting value i1:i1=. Where:

kl is the impact coefficient of the starting current of the motor, generally take kl=; iedm is *

The rated current of a large motor.

Selection of household protective circuit breakers. In the home power supply, the circuit breaker is usually used as a main power protection switch or branch line protection switch. If there is a short circuit or overload in the line or household appliances, the circuit breaker can automatically trip and cut off the power supply, so as to effectively protect these equipment from damage and reduce the accident to a small range.

In the family, monopole (1p) is generally used for branch protection; A two-pole (i.e. 2P) circuit breaker is used for total power protection. It is very important to choose the rated capacity current of the circuit breaker in the family, because if the rated current of the circuit breaker is too large, when the line or household appliances are short-circuited or overloaded, the circuit breaker can not automatically trip and cut off the power supply.

Briefly, you can choose from the following 6 points: 1. First of all, choose according to the rated voltage, and the rated voltage should be consistent. 2. The rated current of the circuit breaker should be greater than or equal to the rated current of the circuit used.

3. The rated breaking current of the circuit breaker should be greater than or equal to the short-circuit current of the circuit used. 4. Select according to environmental conditions, such as altitude, temperature, humidity, and choose a circuit breaker that meets the requirements. 5. Choose a circuit breaker with high quality and cost performance according to the brand.

6. For special breaking conditions, calibrate the circuit breaker.

What do you mean by that?

If you calculate the current to be 180A, then you choose the larger one, the one that is 225A!