How to determine the size of the configuration for the lighting leakage switch

1. The configuration of the lighting leakage switch first considers that the capacity of the main contact must meet the current requirements of the lighting circuit, mainly in the following configuration ways:

The total current is calculated according to the total power of the lighting circuit, and the rated current of the leakage protection switch is selected, that is, the specification. It is calculated as follows:

i=k*p/（u*cosφ

In the formula, k is the efficiency coefficient, which can be selected according to the number of lights turned on at the same time, and 1 can be selected if all the lights are turned on at the same time;

p is the sum of the power of each lamp, in w (watts). u is the voltage of the lighting circuit, and the voltage of the ordinary lighting circuit is single-phase AC 220V;

cos is the power factor. In the early days, the lighting used incandescent lamps, and cos = 1 can be selected, but now the lighting input methods are diverse, capacitive and sensitive, so it is recommended to choose cos =.

After calculating the total current of the circuit, select the specifications of the corresponding leakage protection switch. The rated current specification of the leakage protection switch is a grade standard, and it should be noted that the total current of lighting is less than or equal to the rated current of the switch, that is, the total amount of i. For example:

The total current of lighting i = 30A, then the leakage protection switch with the specification of rated current = 32A should be selected.

The rated current of the leakage protection switch is selected according to the safe ampacity of the wire used in the circuit. Take plastic insulated single-core copper core wire as an example:

The safe ampacity of the four pipe laying is 19A, and the switch of 20A should be selected, such as the specification of 16A, 20A;

The safe current carrying capacity of 4mm four pipes is 24A, and a switch of 25A should be selected, such as specifications of 20A and 25A, and the maximum should not exceed 32A.

2. Configuration of leakage protection device for lighting leakage protection switch.

The leakage protection mode should adopt the current type protection switch that is widely used at present;

Lighting circuit leakage protection is to prevent the human body from directly touching the live conductor of electrical equipment caused by electric shock** accidents, which belongs to direct contact protection. Therefore, a highly sensitive leakage protection switch with an operating current of 30mA and an operating time of less than 30 mA should be selected.

In fact, the protection technical parameters of the leakage protection switch have been debugged by the manufacturer in accordance with the technical specifications and standards, and it is not recommended to debug it by yourself, so as not to damage the overall parameters. Users only need to buy according to their needs.

First of all, we need to figure out a problem. Do you want an air switch or an air switch with leakage protection? The function of the general air switch is to jump when the current is too large to protect the circuit, while the leakage switch is to cut off the circuit when the circuit leaks to protect the safety of equipment and people.

There is not much to say about leakage switches. Generally, the commonly used air switch plus leakage protection provides two types of protection at the same time.

To put it simply, p=u i cos, then we can calculate according to the power of electrical equipment in the home, such as two 4500w air conditioners, 2000w water heaters, etc., add them up, and then divide by voltage 220, and then divide by the power factor. The data obtained is the current size of the air switch you need, and generally you need to add a little on this basis, for example, if you calculate that it is 53 amps, you need to buy a 63 amp switch.

There are many brands of air switches on the market, the commonly used model is: DZ47-63C63, which is an air switch with no leakage protection and a maximum current of 63 amps, and DZ47LE-C10 is an air switch with leakage protection and a maximum current of 10 amps. The last c represents its maximum current.

First calculate the total power p of the load used, if the power supply is 220V, you can calculate the current i=p u, the rated current of the selected leakage switch should be appropriately greater than the calculated current, the selection is too large, no overload protection, and the selection is too small and easy to trip.

First calculate the total power p of all electrical appliances, calculate the total current a number i = p u, when selecting the leakage switch, it should be greater than the total current, and there must be a certain margin, or it will not be able to withstand other electrical appliances. The residual leakage current is 30mA for home use. If you want to protect the line, you need a small circuit breaker, and the small circuit breaker can not be too large.