How do you check the wires when there’s a problem with them on-site?
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Are there a few things that aren’t clear? What fault occurs if the inter-wire resistance is high? What about the resistance to ground? Under what circumstances is it grounded or short-circuited?
Your topic isn’t very clear – is it the high resistance between wires? Which wire has a high inter-wire resistance! The load has not been connected yet; what kind of load is it? If no load is connected, then the load value must be infinite. If the load is something like a transmitter, its resistance will also approach infinity. In the case of solenoid valves or motors, it’s the coil resistance that matters! If it is 24V with respect to ground, insulation from ground is necessary; otherwise there will be a fault. The negative terminal can either be insulated or have a voltage of 0 relative to ground!
The ends of the wire are suspended in the air; when one end is measured with respect to ground, the resistance should be infinite. A low resistance value indicates that the end is grounded. 2. Measure both ends of the wire; if the resistance is low, it indicates a short circuit, whereas it should be infinite under normal conditions.
Inter-wire resistance can be measured using a multimeter; however, the resistance to ground cannot be determined with a multimeter – a megohmmeter is needed to check whether there is resistance to ground.
Inter-wire resistance refers to the resistance between two signal wires, right? If the load is a transmitter, locator, thermal resistor, etc., what value should be displayed when using a multimeter to measure the resistance between those two signal wires under normal conditions? If everything is normal, with one end of the test lead connected to the signal line and the other end to ground, what value should be displayed? Under normal circumstances, what values indicate normal operation and which ones indicate a fault? Also, what are the differences in the measurement results when there is an open circuit? And what is the resistance situation when the signal line is damaged and in contact with ground?
What is a multimeter? Measure resistance. Is a multimeter used to measure current and voltage?
Inter-wire resistance refers to the resistance between two signal wires, right? If the load is a transmitter, locator, thermal resistor, etc., what value should be displayed when using a multimeter to measure the resistance between those two signal wires under normal conditions? If everything is normal, with one end of the test lead connected to the signal line and the other end to ground, what value should be displayed? Under normal circumstances, what values indicate normal operation and which ones indicate a fault? Also, what are the differences in the measurement results when there is an open circuit? And what is the resistance situation when the signal line is damaged and in contact with ground? The load has not been connected yet; what kind of load is it? If no load is connected, then the load value must be infinite. If the load is something like a transmitter, the resistance will also approach infinity. In this case, it’s the resistance of the signal line when it’s floating relative to ground, right? If it’s a solenoid valve, then it’s the coil resistance of the motor or something similar! If it is 24V with respect to ground, insulation from ground is necessary; otherwise there will be a fault. The negative terminal can either be insulated or have a voltage of 0 relative to ground! How should this be understood?
The ends of the wire are suspended in the air; when one end is measured with respect to ground, the resistance should be infinite. A low resistance value indicates that the end is grounded. In this case, it is normal for the resistance measured with the circuit disconnected to be infinite; if the resistance value is low, then there is a grounding fault. 2. When measuring the two ends of the wire, a low resistance indicates a short circuit, while the normal value should be infinite. It is normal for the resistance of the two wires to be infinite when the circuit is disconnected; if the resistance value is relatively low, then it indicates a grounding fault
First, let’s talk about normal situations. Your question is too general, so let’s establish a rule first: your wire refers to the power or signal wire of the transmitter or solenoid valve! If there is no load and it is suspended in mid-air, the resistance between the wires must be infinite! If the resistance between the loaded wires is the resistance of the two wires shorted together (which is very small) plus the load resistance! There are two abnormal situations: first, the quality is not up to standard; in such cases, resistance can still be detected when the device is not under load and is suspended in the air, which can lead to fuses burning out or circuit breakers tripping! Secondly, a fault in the transmitter or valve means, in simple terms, that it has burned out; in such cases, the resistance between the wires is either infinite or consists only of the resistance of the wires themselves Next, let’s talk about grounding. Under any circumstances, the resistance between the live wire or 24V voltage and ground should be infinite; this is the normal condition. If there is a resistance value, it will definitely cause the fuse to blow and prevent power from being supplied. As for the connection between the negative terminal and ground, it can either be conductive or non-conductive, depending on the settings in the electrical system. As for damaged insulation, it generally leads to three situations: leakage current, short circuits, and proper grounding All of these will cause the so-called inter-wire or ground resistance to become abnormal!
A multimeter is also known as a three-function meter; it’s just called by different names.