Active Member
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[China]
Address: 4F,Building 7,Optical Valley International Headquarters Industrial Park,No.62,Optical Valley Road,Wuhan,China
Contact name:
Wuhan Huaying Electric Power Tech & Science Co., Ltd |
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Multi Functional HV Power Cable Fault Locator System High Positioning Accuracy
Product name
Cable Fault Locator HYCF
Introduction
The cable-fault detector is a testing device of good integrity. It
can test on the High Resistance Flashover Fault,
Grounding High and Low Resistance Fault, Short & Off
Circuit on the Cable Fault and Poor contact and etc. If being
equipped with sounding method and locating instrument, it can
exactly detect the fault point. Furthermore, it especially applies
to test for
various power cable and communication cable.
Principle
The electric wave signal will be reflected to injection point in power cable in the special point whose impendence is not match the character impendence.. The character impendence has no connection with the length of cable. HYCF is based on such an electric wave reflection to design the test procedure.
The reflection factor of P is defined as follow:
P=Uf/Ui=(Zo-Zc)/(Zo+Zc)
Uf is defined as the amplitude of reflection voltage
Ui is defined as the amplitude of injection voltage
Zo is defined as the character impendence
Zc is defined as the impendence of any point of cable
If Zc is equal to Zo, it is said this point of cable is ok. So there is no reflection for normal cable.
If the cable is short circuit to the earth, the impendence of the fault point is 0, the reflection factor P is -1 for this cable.
The impendence of the disconnection point of the cable is infinity. The reflection factor for the discontinuity point is 1.
The tester HYCF inject a electric wave signal to the cable from the test point of cable and then measure the reflection of electric wave. If there is negative amplitude voltage is captured it is said there is a short fault in the cable. The time difference from injection time to receive the first reflection wave can be calculated from the reflection curve sampled. And then the distance from injection point to fault point can be calculated by the time and transmission velocity of electric wave in the cable.
The discontinuity of power cable can be measured by the same way of the short circuit fault. The tester sample the reflection curve and then calculate the time from injection time to the time getting reflection factor of 1. And then the distance can be calculated from the time and the transmission velocity of electric wave.
Divided by the injection mode the test method could be defined as low voltage impulse test mode and high voltage impulse test mode.
Technical index
The longest testing distance is 32KM (100KM for the open-wire line)
Testing .dead zone is 1M.
Resolution of reading is 1M
Power dissipation is 5VA
Service condition :
Environment temperature 0℃~+40℃
Terminal temperature -10℃~+50℃
Relative humility 90%RH
Dimension: 225×165×125mm3
Weigh: 2kg
