Generally speaking, the circuit can be divided into single line system and double coil system. However, in the process of using the single line system circuit of the extension arm excavator of construction machinery, there will be some errors, which will affect the smooth progress of the work. The following extension arm excavator rental I will introduce the fault diagnosis method of the electrical circuit fault for you.

　　打破:

　　Break:

　　断路器的故障是当熔断器或自动保护开关完好时，电路开关接通，电气设备不工作。

　　The fault of the circuit breaker is that when the fuse or automatic protection switch is in good condition, the circuit switch is on and the electrical equipment does not work.

　　造成这种故障的原因有三:，电路中的插头是松动的，脱落或有油，第二，开关接触氧化或失效，第三是断了或拿铁丝拿铁不牢固。

　　There are three reasons for this kind of fault: first, the plug in the circuit is loose, falling off or oil; second, the switch contacts oxidation or failure; third, the wire is broken or the latte is not firm.

　　短路:

　　Short circuit:

　　故障表明，当电路主开关或某一电路开关接通时，保险丝烧断，自动保护开关动作，导线发热烧断。这种故障通常是由于电气元件的绝缘子损坏，导致电源线与车身接触。短路检测方法有两种:一种是欧姆计检测方法，另一种是试验灯产生熔丝检测方法。

　　The fault shows that when the main switch of the circuit or a circuit switch is connected, the fuse is burnt out, the automatic protection switch acts, and the wire is burnt out. This kind of fault is usually caused by the insulator damage of electrical components, which causes the power line to contact with the body. There are two short circuit detection methods: one is ohmmeter detection method, the other is test lamp fuse detection method.

　　欧姆表检查方法:切断电路主开关，拆下故障电路的保险丝，将欧姆表1米笔铁，另1米笔连接在拆下的螺纹头上。如果欧姆计测量的电阻值很小，则测量点前面的电路很短，否则故障点在测量点后面。如果欧姆计测量的电阻值正常，则重新连接接线头，然后逐段取出螺纹进行检查。

　　Inspection method of ohmmeter: cut off the main switch of the circuit, remove the fuse of the faulty circuit, connect the 1 meter pen iron of the ohmmeter and the other 1 meter pen on the removed thread head. If the ohmmeter measures a small resistance, the circuit in front of the measuring point is short, otherwise the fault point is behind the measuring point. If the resistance measured by the ohmmeter is normal, reconnect the connector and take out the thread one by one for inspection.

　　试验灯熔丝检查方法:先拆下电气装置开关，然后将试验灯两端与熔丝块两端相连，接通主电路。试验灯亮时，熔断器与电气装置开关之间发生短路;如果测试灯不工作，且测试灯在电气装置的开关接通后才亮，则电气装置与开关之间发生短路。

　　Test lamp fuse inspection method: first remove the switch of the electrical device, then connect the two ends of the test lamp and the two ends of the fuse block, and connect the main circuit. When the test lamp is on, there is a short circuit between the fuse and the switch of the electrical device; if the test lamp does not work and the test lamp is on only after the switch of the electrical device is on, there is a short circuit between the electrical device and the switch.

　　为了确定短路点的具体位置，应逐段拆除缝线。如果测试灯在拆卸后不亮，则表示短路点在拆卸后;另一种方法是在我们打开点之前。为了便于记忆，检查方法可以概括为:连接测试灯，而不是off保险;打开主开关，逐段拆除缝线;后车灯没亮，这部分有点问题。

　　In order to determine the specific location of the short circuit point, the suture shall be removed one by one. If the test lamp does not light up after removal, it means that the short circuit point is after removal; another method is before we turn on the point. For the convenience of memory, the inspection method can be summarized as: connect the test lamp instead of the off fuse; turn on the main switch and remove the suture section by section; the rear lamp is not on, which is a bit problematic.

　　如果一个保险丝或自动保护开关控制多个并联支路，应先拆下所有开关接头，然后将各支路接头逐一连接到端子柱上。当触碰支路时，测试灯的光亮度较低(测试灯与电气设备串联以减小电流)，说明该支路无短路;如果测试灯非常亮，则分支有短路。

　　If a fuse or automatic protection switch controls multiple parallel branches, remove all switch connectors first, and then connect each branch connector to the terminal post one by one. When touching the branch, the light intensity of the test lamp is low (the test lamp is connected in series with the electrical equipment to reduce the current), indicating that there is no short circuit in the branch; if the test lamp is very bright, there is a short circuit in the branch.