The numbering refers to the marking symbol on a specific circuit. The purpose of marking symbols is to install wiring and maintain maintenance to facilitate the drawing, and each circuit needs to be marked to indicate the relationship between each circuit.
First, the main principle of numbering
(1) The same phase or circuit called the equipotential phase, all the wires connected to a point, marked with the same wire number, only when passing through the contact or auxiliary contact of the electrical component, although it is equipotential when it is connected, but it is an unequal potential when disconnected, in this case different wire numbers must be marked.
(2) The circuit marking line number can be grouped according to different line functions, such as the main circuit and the secondary control circuit. At the same time, each set of numbers is assigned to a certain range according to different functions, and then numbered.
Second, the main method of numbering
(1) The number of the main circuit in the AC circuit
Single digits indicate a difference, i.e. the U phase is 1; the V phase is 2; and the W phase is 3. The order of the ten digits distinguishes between different segments, such as U-phase loops with U1, 11, 21... V phase is V2, 12, 22... The W phase is W3, 13, 23... Wait a minute. You can also use L1, L11... L2、L12...... L3, L13 and so on.
(2) The secondary circuit is the number of the control line
The number starts on the side of the power supply and marks the last electrical component in odd order. Then start on the other side of the power supply and mark in even order to the last electrical component that meets the odd number. For example, starting from the A phase, the order is 1, 3, 5, 7, 9, 11, 13, etc. The B phase or C phase of the loop is an even number of labels such as 2, 4, 6, 8, 10, 12, etc.
Third, how to find faults with multimeters?
Knowing the principles and methods of numbering, it is much more convenient to find faults. In general, the main control circuit rarely uses a multimeter because the main circuit configuration is relatively simple. The auxiliary control circuit is relatively complex, when the control circuit fails, there are generally two ways to use a multimeter to find it, that is, resistance file and voltage file.
The use of resistance files to troubleshoot, in the case of line power failure, according to the numbering order of the line number of a segment of analysis and search, is also the simplest troubleshooting method.
Use the voltage file to troubleshoot, is carried out in the case of no blackout, press the start button, use the multimeter voltage file to measure the two terminals of the start button or other components in the order of numbering, if the number of terminals is odd, it means that it is an A phase loop, and there is no voltage generated in the odd number of A-phase potential circuits, if there is a voltage generated, the start button or other components are damaged, and it needs to be replaced.
If there is no voltage, the individual components are good. Next, the red meter pen of the multimeter is placed on the power end of the stop button, and the black meter pen detects the other terminal of the stop button or other even components, and the voltage is damaged, until it is found that there is a point generated by the voltage, which is the fault part of the circuit.
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