Including transmitter, receiver, inductive probe, potential type detection frame.
All kinds of power cable with metallic conductor.
Locating poor insulation point, detecting circuit and depth of power cable.
- Low static drift
- High accuracy of locating
- LCD screen to show signal and status
- Built-in rechargeable Li-battery
Tracing and locating distance: local cable 3km, other cable up to 20km
- Fault impedance resistance:0-5MΩ
- Locating accuracy: ≤±10cm.
- Detection cable depth: <3m.
Working principle of instrument:
1 .Tracing principle (maximum signal method)
We know that when alternating current flows through a conductor, an alternating magnetic field is generated around the conductor, and the magnetic lines of the magnetic field are coaxial with the conductor. At this time, if an electromagnetic coil is placed in the magnetic field, both ends of the coil will generate an induced voltage. When the coil is in the same direction as the magnetic field line, the induction voltage at the two ends of the coil will be maximum. That is, when the coil direction is perpendicular to the conductor direction, the induced voltage is the maximum (Figure 1); when the coil direction is parallel to the conductor direction, the induced voltage is minimum (shown in Figure 2). Thus, we obtain the maximum signal method to explore the trajectory of buried cables, and the buried depth of underground cables can be measured by using the 45 degree law of the receiving coil.
2.1 Differential potentiometry
If a grounded fault occurs in a buried cable, we can use the potential difference method to find the fault point. The method is to add a test voltage between the test point of the faulty cable and the ground, then, around the point of the cable, a distributed electric field with concentric points is formed. The electric field in the same radius at any point there is no potential difference, but different between two arbitrary radius has potential difference (Figure 2 A, B), and when the distance of two points is fixed, two from the center near the potential difference is stronger. With this feature, we can move A and B, and two points approach to the center point gradually. When the fault point is between A and B, the potential difference becomes zero. If you continue to move past the fault point, the potential difference polarity will be reversed, so you can move back and forth to accurately determine the location.
2.2 Shock detection method
When the cable presents high resistance fault, the impulse flashover method must be used to detect the fault. The fault point discharge to the ground, creating slight vibration. At this time, the method of using sensor to detect the epicenter is used to find the fault point.
HIMALAYAL provides innovative products that comprise high voltage test equipment, full-set high voltage test instruments, on-site test systems and on-line monitoring systems, and services regarding tests, diagnostics and asset monitoring for clients in power industry. We help to ensure safety and reliability in the power generation, transmission and distribution.