Author: Noyafa–CCTV Monitor Tester
Let's learn how to use the low-voltage cable fault tester. Connect the terminal to ground. In general, let's learn how to use the low-voltage cable fault tester. The terminal needs to be connected to the ground. Generally, the signal is added from the end of the cable to the direction of the power distribution cabinet.
(2)"Insulation resistance - signal output"Dial the signal output, turn the control selector switch to the direction"routing"Audio in the file (generally choose audio, radio frequency is suitable for close-up hardened roads and occasions with interference). ⑶ Put the receiver in the"RF-Audio"Dial to the gear corresponding to the transmitter, when"control selector switch"Dial to"zero value"When selecting the audio receiver directly above the cable under test, the received sound is small, when"control selector switch"Dial to"peak"When selecting the RF receiver, the sound received directly above the cable under test is louder. Adjust the receiving adjustment during the test, so that the received signal is clear and the sound should not be too loud.
⒉ How to detect the buried depth: When outputting the transmitter according to the audio signal, put the antenna box of the receiver on the ground just above the cable under test,"control selector switch"dial to set, adjust"Receive adjustment"Turn the knob to make the pointer of the receiver's meter point to the set position, and then turn the"control selector switch"Dial to the peak value, then slowly move the receiver vertically upward, observe the meter head of the receiver, when the pointer of the meter head returns to the set position, the height moved by the receiver is the buried depth. ⒊ How to locate the fault: If the cable under test is faulty, select the phase with serious fault as the test phase. Then connect the transmitter as shown in Figure 2, and connect the"control switch"orientation"Fault"audio or RF in the receiver’s"RF-Audio"Set the signal corresponding to the transmitter; install the detection bow, connect the fault jack and the detection bow with double Q lines, turn on the power of the instrument, and a clear signal should be received in front of the transmitter, and then the detection will be detected in front of the grounding stake. The bow is inserted into the ground (between the ground wire and the instrument), and the meter head of the receiver should have a stable indication (should point to the far end), indicating that the instrument is normal; the next step is to follow the path of the cable to detect the fault point. Detect every 3-4 meters, and observe whether the meter head of the receiver has a stable indication (when detecting, place the probe bow steadily and reverse the measurement twice, observe the indication of the meter head, if it is unstable, swing it back and forth, indicating that there is a nearby There is no fault point, continue to test), when the color indicated by the meter head is the same as the color in front of the detection bow, it means the fault point is in the front, otherwise it means the fault point is behind, that is, it has passed the fault point, it should be reversed When you search and find the pointer transition point, you will also find the fault point.
⒋How to find the fault of disconnection and ungrounding: Set the transmitter gear to the faulty RF output, the receiver reaches the peak value, use the method of RF to find the path, and adjust the receiving knob next to the path to make the sound of the receiver low and smooth. The received RF signal is clear, the pointer should point to the smaller position of the red zone, then move the receiver forward and left and right back and forth smoothly along the path, observe the change of the meter, before the disconnection point, the sound becomes louder just above the cable At the same time, the meter head swings to the green area and the point is large. When the disconnection point is passed, the meter head will not swing to the green area and the signal suddenly decays and disappears. In this way, carefully find the point where the meter head does not swing, this is the disconnection fault point . ⒌How to distinguish the main and secondary fault points: Set the gear of the transmitter to the fault audio and the gear of the receiver to the peak position. At this time, the meter head points to the green area. Adjust the receiving knob directly above the cable to make the meter head Float up, and then walk smoothly along the path to observe the change of the meter head. At the main fault point, the meter head will point from the green zone to the red zone. At the secondary fault point, the meter head will not swing from the green zone to the red zone. area (or the swing is not as large as the former), so that the real fault point can be judged.
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