Cable Fault Detector (English name: Cable Fault Detector) is a comprehensive cable fault detection instrument. It can test high-resistance flashover faults, high and low resistance grounding, short circuits, cable breaks, poor contact and other faults.
Technical Indicators
1. Maximum test distance: 32km
2. Detection blind zone: 1m
3. Reading resolution: 1m
4. Power consumption: 5VA
5. Operating conditions: ambient temperature 0℃～+40℃ (extreme temperature -10℃～+50℃)
Relative humidity 40℃ (20～90)%RH
Atmospheric pressure (86～106) Kpa
6. Volume: 225×165×125mm3 8. Weight: 2kg
1 Traditional cable fault detection methods
1.1 Resistance bridge method
This method has remained almost unchanged for decades. For short-circuit faults and low-resistance faults, this method is very convenient to measure. The bridge method uses the principle that when the bridge is balanced, the product of the corresponding bridge arm resistances is equal, and the length of the cable is proportional to the resistance.
1.2 Low-voltage pulse reflection method
The low-voltage pulse method is also called time domain reflectometry (TDR), which refers to the pulse reflectometer independently measuring low-resistance and open-circuit faults of cables without passing through a high-voltage impactor.
1.3 Pulse voltage sampling method
The pulse voltage sampling method, also known as the impulse high-voltage flashover method, is a test method used to measure high-resistance leakage and flashover faults. First, the cable fault is broken down under DC or impulse high-voltage signals, and then the distance is measured by recording the time required for the discharge pulse to travel back and forth between the measurement point and the fault point. The pulse voltage method mainly includes DC high-voltage flashover (direct flash method) and impulse high-voltage flashover (impulse flash method).
1.4 Traditional methods for cable fault pinpointing
① Acoustic measurement method
This method uses the breakdown discharge sound of the fault point under high-voltage impact for precise location.
② Acoustic-magnetic synchronization method
Traditional Methods
1.1 Resistance bridge method
1.2 Low-voltage pulse reflection method
1.3 Pulse voltage sampling method
1.4 Traditional methods for cable fault pinpointing
① Acoustic measurement method
This method uses the breakdown discharge sound of the fault point under high-voltage impact for precise location.
② Acoustic-magnetic synchronization method
③ Audio induction method
When impulse DC high voltage is applied to the cable to discharge the fault point, a pulsed magnetic field is generated around the cable. When receiving the pulsed magnetic field signal during acoustic pinpointing, it can be considered that the discharge sound is emitted from the cable fault point.
③ Audio induction method
This method is generally used to detect low-resistance faults. The principle is: use a 1kHz audio signal generator to inject audio current into the cable under test, causing the cable to emit electromagnetic waves. Receive the electromagnetic field signal on the ground, amplify it, and then send it to earphones or an indicating instrument. Determine the location of the fault point based on the strength of the sound or the magnitude of the indicating instrument value.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
