| Features
: |
|
- For prelocation
of faults in conjunction with Computer Aided Fault Locator in
impulse current & Arc Reflection
/ SIM mode.
- For proof
testing of cables & faults.
- For pinpointing
of faults by acoustic method.
- Heavy duty
continuous operation.
- Extremely
safe to operate.
- Inter locks
negates all wrong sequences of operation.
|
Application
:
Surge Wave Testers are primarily used for acoustic pinpoint location
of cable faults. To be successful in pin-point location of cable
faults, the resistance of the faults must by high. A short circuit
fault can not be locatead by this method. In some cases however,
it may be possible to open up the short circuit by feeding a few
shock wave surges into the cable. By this way, the fault gets conditioned
for the application of the acoustic method of pinpointing. |
Pre-location
of High Resistance Faults :
The Surge Wave Testing instrument in conjunction with a Digital
fault locator can be used to pre-locate faults by the impulse current
method or by short term arc reflection / sim method. |
In
the impulse current method a current coupler (similar to a few turn
CT) is used for coupling the Computer Aided fault locator with Surge
Wave Testing Instrument. For the Arc Reflection/SIM method, an adaptor
is used. This adaptor will be able to sustain the arc creatd by
the surge testing instrument for a longer duration. During this
sustenance the echograms can be recorded in the memory without the
transient recording facility. |
Pin-Pointing
of Cable Faults :
The Surge Wave Testing Instrument is connected to the faulty core
and sheath or between two cores as may be required and set into
a continuous impulse mode. The impulse mode selection is done by
setting the timer anywhere between 1.5 to 6 sec. During this set
time the impulse capacitor configured in-series/series parallel
will charge and discharge the stored energy into the cable and subsequently
into the fault, Surge impulses will give rise to acoustic and electro
magnetic signals at the point of fualt. The seismic vibration formed
as a result of these discharges can be amplified and received by
means of ground microphone, an acoustic receiver and headphones. |
Safety
:
There are several interlocks that ensure that the instrument can
be switched `ON’ only if a few conditions have been fulfilled.
HV output cannot be produced in case variac control is not brought
to zero position at the start or HV output selector switch/output
cable is not secured properly/HV transformer, due to any reason,
is overheated (beyond 72ºC). An automatic earth discharge ensures
‘soft discharge’ of surge capacitors and the cable under
test in case of switching off/mains failure, there by making the
working conditions absolutely safe. |
