Sheath Fault Tester

 

Locator SFL 1

 

Description

Sheath fault locator SFL1 is a powerful system. It is an intact sheath of a plastic insulated medium, high or extra high voltage cable is the prerequisite for the avoidance of water ingress and subsequent cable faults. Different test can be carried using sheath fault locator SFL1. Sheath/earth faults can develop in any type of underground cable network such as low, medium, high voltage power cables or unshielded multi core control cables. It can be a manufacturing defect or can be caused by improper handling during laying / external damage/any other reason due to which the metallic armor or cores develop leakage with the mass of earth. These faults can remain undetected for a long time as they do not hamper the working of the cable. It develops into a fully fledged fault over a period of time. 
That can successfully locate sheath/earth faults on any type of cable. It offers different modes such as DC test / HV Test, Burning, pre-location and pin-pointing.

DC/proof Test:
Completely isolated cable (including earth connections removed at both ends) is subjected to HV Test up to 5 kV DC with respect to the mass of earth. This gives diagnostic result of the health of the insulation of the cable under test. 

Burn test:
A high resistance nature of the fault on the cable can be altered by burning it. This is necessary in some specific cases. 

Pre–Location:
It derives Voltage drop from either end of the cable, which is then used for evaluating the fault distance from the test end using bridge method. Voltage drops on the conductors are measured on either side of the cable with respect to earth. 41/2 digit meters offers precise readings required for calculating fault distance. 

Pin–Point: 
Output of sheath fault locator is connected between the cable sheath and the mass of earth in pulse mode. The DC current flows through the cable up to fault point and returns back through the mass of the earth to the sending or source end. This produces currents in the ground whose paths fan out at the fault point. These currents can be monitored by two metallic ground sticks connected to a highly sensitive receiver EFL1. Center zero galvanometer on the receiver gives deflection in one direction before the fault point on the cable length and changes the direction beyond the fault point. Null is achieved at the fault point. This is how the condition exact point of output is connected between the cable and the damage is pin-pointed effectively. 

 

Application

Sheath fault tester is use to conditioning / DC test / burn, pre-locate and pin-point sheath faults in underground extra high voltage power cable transmition networks.

 

Working Principle

Completely isolated cable (including earth connections removed at both ends) is subjected to HV Test up to 5 kV DC with respect to the mass of earth. This gives diagnostic result of the health of the insulation of the cable under test. A high resistance nature of the fault on the cable can be altered by burning it. This is necessary in some specific cases. SFL derives Voltage drop from either end of the cable, which is used for evaluating the fault distance from the test end using bridge method. Voltage drops on the conductors are measured on either side of the cable with respect to earth. Digital meter offers precise readings required for calculating fault distance. 

Output of sheath fault locator is connected between the cable and the mass of earth at pulsed mode. The DC current flows through the cable up to the fault point and returns back through the mass of the earth to the sending end. This produces currents in the ground whose paths fan out at the fault point. These currents can be monitored by two metallic ground sticks connected to a highly sensitive receiver with center zero galvanometer gives deflection in one direction before the fault point on the cable length and changes the direction beyond the fault point. Null (no deflection) is achieved at the fault point.

 

Function

Sheath Fault Locator is a device that works on the potential difference voltage method for cable testing, cable sheath testing, fault pre-location and fault pin pointing. It works on the bridge measuring principle using the Murray loop method. The fault pre-location analyses are done automatically with feeding proper data and the results are displayed digitally.

 

Features

 

There manually selectable convince DC ranges for application.

 

Cable and cable sheath testing up to 5 kV between metallic sheath / armour and mass of earth.

 

Automatic sheath fault pre-location with high precision measuring bridge method.

 

Cable sheath fault pin pointing by pool of potential method.

 

Burn mode for conditioning the sheath fault.

 

Conversion of high-resistance faults in low-voltage cables.

 

Maximum 400 mA current gives better results.

 

It is extremely user friendly in obtaining the fault distance; it uses a micro-controller based fault distance calculator that enables the operator to get the pre-location measurements with precise accuracy.

 

Automatic discharging facility of cable under test, in case of power failure or after switching off.

 

Continues operation for extended period in case of pin-point difficult sheath faults.

 

Rugged construction and easy to carry on site.

 

Specifications

 

Power Supply

230V,+/-10%,50 Hz single phase

 

Test Voltage

0-2.5 and 0-5 kV DC continuously variable

 

Test Current

2.5 kV- 200 mA, 5 kV- 100 mA

 

HV range Selection

Manual

 

Indication

1) On / off lamp indication
2) Analog moving coil meter for output voltage (kV) indication
3) Analog moving coil meter for output current (mA) indication 
4) Over heat LED indication 
5) Sheath voltage drop indication on DPM (0-1.9999V)
6) Fault pre-location distance on LCD display.

 

Pulse ratio for pin-pointing

1:3 sec, and 1:6 sec selectable on off time ratio

 

Fault Distance Calculator

LCD display-16 x 2 characters with back light

 

DPM power supply

6 V, 1.5 Ah rechargeable battery

 

Over load Protection

1) Main Input current MCB switch in Live
2) Fast blow fuse in input mains supply

 

Safety Protections

1) Variac Zero inter-lock.
2) Output cable Plug inter-lock
3) HV Switch inter-lock
4) Over Heat Protection
5) Emergency off switching

 

Earth Discharge

Soft automatic discharge through in-built solenoid

 

Cooling system

Air cooling

 

Operating Temperature

0oC to 55oC

 

Storage Temperature

- 5oC to 60oC

 

Dimensions

485 (L) x 304 (W) x 415 (H) mm + Handle 50mm + Wheel 65mm

 

Weight

52 kg Approx

 

Standard Accessories

 

10 sq mm single core screen output HV cable with heavy duty brass clamps 5 meter length

 

Dual single core cable for pre-location 5 meter length

 

Two single core cable for pre-location 5 meter length

 

Mains supply connecting cord 3 meter

 

Yellow/green earthing cable 5 meter

 

External Battery charger for DPM supply

 

Standard Warranty - One Year

Standard Models -

Sheath fault tester SFL12 
Associate pin-point receiver to be use with Sheath fault Tester SFL5 is Sheath fault receiver EFL1

 

 

 

 

 

 

Locator SFL 12

 

Description

Sheath Fault Tester SFL12 is a powerful system. It is an intact sheath of a plastic insulated medium, high or extra high voltage cable is the prerequisite for the avoidance of water ingress and subsequent cable faults. Different test can be carried using sheath fault locator SFL12.

Sheath/earth faults develops in any type of underground cable network such as low, medium, high voltage power cables or unshielded multi core control cables. 

It can be a manufacturing defect or can be caused by improper handling during laying / external damage /any other reason due to which the metallic armor or cores develop leakage with the mass of earth. These faults can remain undetected for a longtime as they do not hamper the working of the cable. It develops into a fully fledged fault over a period of time.

That can successfully locate sheath/earth faults on any type of cable. It offers different modes such as DC test / HV Test, Burning, pre-location and pin-pointing.

 

Application

It is use to Conditioning / DC Test / Burn, Pre-locate and Pin-point sheath faults in underground extra high voltage power cable transmission networks.

 

Features

 

Three manually selectable convince DC ranges for application.

 

Cable and cable sheath testing up to 12 kV between metallic sheath / armour and mass of earth.

 

Automatic sheath fault pre-location with high precision measuring bridge method.

 

Cable sheath fault pin pointing by pool of potential method.

 

Burn mode for conditioning the sheath fault.

 

Conversion of high-resistance faults in low-voltage cables.

 

Maximum 400 mA current gives better results.

 

It is extremely user friendly in obtaining the fault distance; it uses a micro-controller based fault distance calculator that enables the operator to get the pre-location measurements with precise accuracy.

 

Automatic discharging facility of cable under test, in case of power failure or after switching off.

 

Continues operation for extended period in case of pin-point difficult sheath faults.

 

Rugged construction and easy to carry on site.

 

Working Principle

Completely isolated cable (including earth connections removed at both ends) is subjected to HV Test up to 12 kV DC with respect to the mass of earth. This gives diagnostic result of the health of the insulation of the cable under test. A high resistance nature of the fault on the cable can be altered by burning it. This is necessary in some specific cases. SFL derives Voltage drop from either end of the cable, which is used for evaluating the fault distance from the test end using bridge method. Voltage drops on the conductors are measured on either side of the cable with respect to earth. Digital meter offers precise readings required for calculating fault distance.

Output of sheath fault locator is connected between the cable and the mass of earth at pulsed mode. The DC current flows through the cable up to fault point and returns back through the mass of the earth to the sending end. This produces currents in the ground whose paths fan out at the fault point. These currents can be monitored by two metallic ground sticks connected to a highly sensitive receiver with center zero galvanometer gives deflection in one direction before the fault point on the cable length and changes the direction beyond the fault point. Null (no deflection) is achieved at the fault point. 

 

Function

Sheath Fault Locator is a device that works on the potential difference voltage method for cable testing, cable sheath testing, fault pre-location and fault pin pointing. It works on the bridge measuring principle using the Murray loop method. The fault pre-location analyses are done automatically with feeding proper data and the results are displayed digitally. 

Specifications

 

Power Supply

230V AC + 10%, 50 Hz Single phase

 

Test Voltage

0 - 3, 0 - 6 and 0 - 12 kV DC continuously variable

 

Test Current

3 kV - 400 mA, 6 kV - 200 mA, 12kV - 100 mA DC

 

HV Range Selection

Manual

 

Indication

ON / OFF lamp indication, 
Analog moving coil meter for output voltage (kV) indication, 
Over heat LED indication, 
Analog moving coil meter for output current (mA) indication,
Fault pre-location distance on LCD display & Sheath voltage drop indication on DPM

 

Pulse Ratio for Pin-pointing

1:3 second and 1:6 second selectable ON OFF time ratio

 

Fault Distance Calculator

LCD display - 16 x 2 characters with back light

 

DPM Power Supply

6 V, 1.5 Ah Rechargeable battery

 

Over Load Protection

Mains Input current MCB switch in Live & Fast blow fuse in input mains supply 

 

Safety Protections

Variac Zero inter-lock, 
Output cable Plug inter-lock, 
HV Switch inter-lock, 
Over Heat Protection & Emergency OFF switching

 

Earth Discharge

Soft automatic discharge through in-built solenoid

 

Cooling System

Air cooling

 

Operating Temperature

0oC ~ 55oC

 

Storage Temperature

- 5oC ~ 60oC

 

Dimension

555 (L) x 355 (W) x 570 (H) mm + Handle 50mm + Wheel 65mm

 

Weight

70 kg Approx

 

Standard Accessories

 

HV Output Cable 10 sq mm single core screen cable 5 meter length with heavy duty clamp.

 

Mains supply cord 3 meter length.

 

Yellow / Green 10 sq mm earthing cable 5 meter length

 

Standard Warranty - One Year

Other models available