Cable Fault Detector (English name: Cable Fault Detector) is a comprehensive cable fault detection instrument. It can test faults such as high resistance flashover faults, high and low resistance grounding, short circuits, cable breaks, and poor contact.
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, 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 quite 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 cable length 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 the cable without passing through a high voltage impulse generator.
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 pulse high voltage signals, and then the distance is measured by recording the time it takes for the discharge pulse to travel back and forth between the measurement point and the fault point. The pulse voltage method mainly includes two methods: DC high voltage flashover (direct flash method) and impulse high voltage flashover (impulse flash method).
1.4 Traditional methods for cable fault location
�� Acoustic method
This method uses the breakdown discharge sound of the fault point under high voltage impulse 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 location
① Acoustic method
This method uses the breakdown discharge sound of the fault point under high voltage impulse for precise location.
② Acoustic-magnetic synchronization method
③ Audio frequency induction method
When applying impulse DC high voltage to the cable to discharge the fault point, a pulse magnetic field is generated around the cable. When receiving the pulse magnetic field signal during acoustic location, it can be considered that the discharge sound is emitted from the cable fault point.
③ Audio frequency induction method
This method is generally used to detect low resistance faults. The principle is: use a 1kHz audio frequency 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 indicator meter. Determine the fault point location based on the sound intensity or the indicator meter value.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
