1. Before decoration, there must be (strong current and weak current) construction drawings, and electrical engineering completion drawings shall be provided upon completion.
2, electrical installation construction personnel should hold relevant certificates.
3, wiring should be color separation, phase line (L) color should be unified, zero line (N) should be black, protection line (PE) must be yellow and green.
Extended data:
The basic working principle of the electric indicator is to convert the measured electric quantity or non-electric quantity into the deflection angular displacement of the movable part of the indicator. The measured can not be directly added to the measuring mechanism, and it is generally necessary to convert the measured into a transition quantity that can be measured by the measuring mechanism. This part which is converted into transition quantity by measurement is called measuring circuit. The mechanism that converts the transition quantity into deflection angle according to a certain relationship is called measuring mechanism. The measuring mechanism consists of a movable part and a fixed part, which is the core of the instrument. Electric indicating instrument is generally composed of measuring circuit and measuring mechanism.
The main function of the measuring mechanism is to generate the rotating torque that deflects the indicator of the instrument, as well as the reaction torque and damping torque that make the indicator keep balance and stability quickly.
When the measuring circuit converts the measured electric quantity or non-electric quantity into the electric quantity that can be directly measured by the measuring mechanism, the movable part of the measuring mechanism deflects under the action of the deflection torque. At the same time, the reaction moment generated by the part of the measuring mechanism that generates the reaction moment also acts on the movable part. When the rotational moment is equal to the reaction moment, the movable part stops.
Because the movable part has inertia, it can't stop quickly when it reaches equilibrium, but swings back and forth near the equilibrium position. The damping torque generated by the damping device in the measuring mechanism makes the pointer quickly stop at the equilibrium position and point out the measured size, which is the basic working principle of the electrician indicating instrument.
There are many kinds of electrical measuring and indicating instruments, and their classification methods are also varied. Understanding the classification of electrical depth indicators is helpful to understand their characteristics and the general situation of electrical gold measurement indicators.
The following introduces the classification methods of several commonly used electrical measuring and indicating instruments.
(1) is divided into magnetoelectric system, electromagnetic system, induction system, electrostatic system and so on according to the working principle.
(2) There are ammeters (ammeters, milliammeters and microamperes), voltmeters (voltmeter and millivoltmeter), power meters, watt-hour meters, power factor meters, frequency meters, megohmmeters and other multimeters, such as multimeters.
(3) According to the type of current to be measured, there are DC meters, AC meters and AC /DC meters.
(4) According to the mode of use, there are switch-type and portable instruments. Switchboard instruments are usually fixed to switchboards or equipment. 7. The general error is large and the price is low, which is suitable for general industrial measurement. Portable instrument has small error (high precision) and high price, which is suitable for laboratory application.
(5) According to the accuracy of the instrument, it is divided into seven grades: 0. 1, 0.2, 0.5, 1.0, 1.5, 2.5, 5.0 * *.
In addition, according to the defense ability of the instrument to electromagnetic field, it is divided into four grades: I, II, III and IV. According to the use conditions of the instrument, it is divided into three groups: A, B and C.
References:
Baidu encyclopedia-electrician