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JYZ-FF Remote Overhead Fault Indicator

The JYZ-FF-C (indicator) & JYZ-FF-HD (data concentrator) Remote overhead Line Fault Indicator (RFI)is used in 5~38KV overhead line networks, enable the electricity distribution network engineers to quickly identify the faulty section of network and restore power supplies to customers on healthy sections in the shortest time possible. 
A high accuracy current sensor in the JYZ-FF-C line fault detector, monitors the phase current flowing. When detecting current level exceeds a user-selectable threshold (as a result of a phase-to-phase or phase-to-ground fault), the fault is indicated by mechanical Flag and flashing, high-power LED, and at the same time send the fault message to the JYZ-FF-HD. The JYZ-FF-HD will transmit the data to the central monitoring station over the cellular network. Combined with GIS and SCADA, the central monitoring station could accurately locate the faulty section and send the maintenance crew man to the faulty section for troubleshooting.
The fault is located between the last Indicators that has been triggered and the first one which is still inactive. The path of the fault current from the feeding point to the fault location is marked by the triggered indicators.
The unit of line fault detector resets is optional either automatically when power to the line is restored, or after a user-selectable timer period, or could manual remote reset from ground level.
The fault passage indicators can be mounted under live conditions with the help of an adapter and a hot stick. The Electric Fault Indicator could be self-sustained by the monitored network from a current flow of 10A upwards. The line fault indicator also with built-in lithium battery that could powered the fault locator for more than 10 years.

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Main Technical Parameter:
  • Real time remote monitoring the current status 
  • Remote management of Faulted Circuit Indicator and data concentrator
  • LED indication with 360 degrees of visibility
  • Dual indication (High-Visibility Flag & High-Power LEDs)
  • Remote monitoring the line current status
  • Mounting can be performed while equipment is energized
  • Hot-stick Line-mountable
  • User-selectable fault trip level
  • User-selectable fault response time
  • User-selectable reset time after power return
  • Manual remote reset from ground level

System Composition
The system is composed of indicator(JYZ-FF-C), Data Concentrator Unit(JYZ-FF-HD), Monitoring central Station.
Overhead Installed part include: 
Indicator : 3pcs/SET. Respectively installed in A,B,C three phase overhead cable, can send and receive signals of line fault. 
When detect the short-circuit or earth fault, the fault circuit indicator will trigger mechanical flag, flashing LED and at the same time send out the fault message to data concentrator unit via wireless RF 433MHz . 
Data concentrator Unit: Installed on the wire pole, one data concentrator unit can receive data from nearby three line fault detector and send to central station by GPRS/3G/4G LTE cellular network. The data concentrator Unit is mainly composed of the solar panel and industrial modem.
Monitoring central station include: 
One set data server with software system. Monitoring central station usually setup in power utility office, power substation, etc. When receiving the fault message from the data concentrator unit, combined with GIS system, the maintenance crew man could quickly locate the fault site and trouble-shoot. 
The software system could be SCADA or other software platform, usually power utility companies have their own software system. Four-faith also have our own-developed software system.
Remote Overhead Fault Indicator
Note: If customers use their own software system, then should offer Four-faith the software data communication protocol format, so that the FOURFAITH data concentrator could be able to communicate with the software system.
Operation worked example
Local indication
On detection of fault current above the fault sensitivity threshold and for the minimum required duration the JYZ-FF-C fault locator will respond both by mechanical Flag Indicate, and flashing, high-power LED indicate. 
Indicator in ready status Indicator in flag &flashing status

Remote Indication
With the monitoring central station, the maintenance crew man could be able to accurately locate the fault section via the GIS in the software system, thus save a lot of time for troubleshooting.

Locate the fault section in the FOURFAITH software which embedded with Google map

Indication period & reset
The indication period is user-selectable. The default value is 12 hours flag&flashing when a fault is detected. 
If the fault section restore power sooner than the default value (let’s say, 12 hours), then the indicator will return to the ready state (flag return from red to white, LED not flash) ; If the fault section still not be able to restore power after the default value (12 hours), then the indicator still will return to the ready state.
Also, the reset could be manually achieved by the software system.

Identify the fault section
local identification
The fault is located between the last indicator that has been triggered and the first one which is still inactive. The path of the fault current from the feeding point to the fault location is marked by the triggered indicators. 
Note: The diagram above indicate that the fault section is between the point 5 and point 6.

Remote identification
localized the fault section showing in the software system

Indicator installation
The current indicator can be mounted under live conditions with the help of an adapter and a hot stick. 
Four-faith offer the adapter like below. Hot stick not offer since it is universal.
Put the indicator into the adapter and fix the the spring of the indicator with the hook of the adapter.

JYZ-FF-C (indicator)
Applicable voltage range 5~38KV
Applicable current range 0~600A
Applicable power frequency range 45~60Hz
Angle of visibility 360°flashing insight
Fault flashing interval 5s
Duration of flashing 50ms
Sensitivity&accuracy 0A~100A: ±3A 
100A~600A: ±3%
Static power consumption less than 20uA
Auto reset time 1~48h user-selectable
Identification of fault current duration 20ms~40ms
MTBF more than 70000h
Impulse current withstand 31.5kA for 2s
Degree of protection IP67
Weight less than 540g
Outline dimension Ф75mm * 115mm


JYZ-FF-HD (data concentrator)
Short circuit fault upload Receiving and upload fault information and fault current
Ground fault upload Receiving and upload fault information and fault current
Load current Upload load current value,Timing or out-of-limit upload
Low battery alarm Receiving and upload Low battery alarm function
Heartbeat function Timing upload heartbeat information
Status measurement Active measurement switch status and load current
Remote management Remote management fault indicator, such as parameters, reset etc
Local and remote maintenance Have local and remote upgrade function
Stability mechanism WDT design, to ensure the stability of system
Identification of fault current duration 20ms~40ms
IEC support Support IEC60870-5-101
Shell 304 stainless steel+ RAL7305
protection class IP67
Outline dimension Ф355*293*255mm
Weight 5Kg

Electrostatic discharge
Can withstand the GB/T 17626.2 of the IV level of electrostatic discharge interference test
Contact discharge: + 8KV
Air discharge: + 15KV
EFT/B immunity test
Can withstand the GB/T 17626.12 of the IV class fast pulse group interference test
Voltage peak value: 2KV
Frequency: 5KHz & 100KHz
Radiated susceptibility Can withstand the GB/T 17626.3 of the IV level RF electromagnetic field immunity
Field strength: 30V/m
Surge immunity
Can withstand the GB/T 17626.5 of the IV level surge (impact) interference test
Common mode voltage: 4KV ± 10%
Differential mode voltage: 2KV ± 10%
Power frequency magnetic field immunity Can withstand the GB/T 17626.8 of the V level power frequency magnetic field immunity interference test
Magnetic field intensity: 100A/m
Damped oscillatory magnetic field immunity Can withstand the GB/T 17626.10 of the V level damping oscillation magnetic field immunity test
Damped oscillatory magnetic field intensity peak value: 100A/m


Environment temperature Operation temperature: -35℃~80℃(-31~+176℉)
Storage temperature: -40℃~85℃(-40~+185℉)
Relative humidity 5~95%( No condensing)
Altitude ≤4000m