Megger SG32-1500M, User Manual

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SG32-UG-EN-V01 Dec 2016
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Description of Arc Reflection
The Arc Reflection method is based on standard TDR techniques to prelocate
high resistance faults, which are not identifiable using TDR by itself.
In Arc Reflection we use an Impulse Generator, Arc Reflection Filter and the
MTDR100. The operator takes a standard TDR trace which is automatically
saved as a reference trace. An HV impulse is applied to the cable, the impulse
going through the Arc reflection filter. This arc reflection filter “stretches” in
time, the outgoing pulse which then ignites the fault, creating a temporary arc
/bridge to earth/ground. During this period the MTDR sends out LV TDR
pulses into what is in effect a short circuit, creating a negative / downward
reflection. The trace is saved and compared to the original trace. The point of
divergence is the point of fault.
Typical Traces
This method is extremely effective and easy to interpret.
SG32
Surge
Generator
Thumper