1. The operator shall read the instruction manual in advance, and master the functions, working methods, work preparation before test and correct test requirements of the instrument.
2. Before the test, disconnect both ends of the tested cable with armored grounding, and connect the remote end (end) of the core wire with the ground.
3. The two output lines of the instrument shall be respectively clamped red to the core wire of the cable under test and black to the ground as required.
4. Before opening the transmitter, the anti-clock of the output adjusting knob must be rotated to the zero position before starting up. Slowly adjust the output adjusting knob to make the output reach 5a-15a (the adjusting knob is generally adjusted within the two-thirds range). If the grounding resistance value of the distribution station system is greater than 4 ohms, the output current is less than 8A, and the receiver meter head can normally work as long as it can deflect in the positive and negative directions. 1. Note: when used at the scene, if the grounding resistance is too small, the transmitter output adjusting knob in the clock cycle to zero, the output current will be very big, transmitter within a protection circuit action (show the header has a small swing quickly), then can be random distribution of high power test resistance (1 to 2 ohm / 20 w - 30 w) concatenated in the transmitter loop.
In article 2, the actual test, the same cable conduit and other cable connection between the two transformer room more than two, grounding resistance because there are other running armoured cable connected and the change is very small, even close to zero, the transmitter output current is too large and protective circuit, then test the resistance can be concatenated in the transmitter loop test. After the test, the temperature of the test resistance is very high. Please note that the test resistance can also be replaced by other 1-2 ohms resistance greater than 20W.
V. before identifying the cable on the spot, calibrate the receiver of the identification instrument at the beginning of the cable according to the requirements of instrument calibration in the instruction manual.
Vi. Standards for field identification of cables: when the sensor is stuck on one of the cables for testing, the receiver meter head will deflect to one side and swing more. When testing on the other cables (keep the same stuck direction of the sensor), the receiver meter head will deflect to the other side and swing less. The cable that the receiver meter head deflects to one side and swings greatly is the cable that needs to be identified.
