Patent ID: 9557349
Date: 2017-01-31
CPC Classifications: G01R

Claim:
1. A measuring system for continuously monitoring a high-voltage bushing, the measuring system comprising: a measuring circuit for monitoring the high-voltage bushing; a connecting plug for connecting said measuring circuit to a measuring connection of the high-voltage bushing; a connecting cable for connecting said measuring circuit to said connecting plug; and a protection circuit for protecting said measuring connection from over voltages, said protection circuit being configured to establish a short circuit between a high-voltage terminal and a ground terminal of the measuring connection if an overvoltage occurs; said protection circuit including a first protection stage, a second protection stage electrically connected in parallel with said first protection stage, and a third protection stage; said first protection stage including a low-pass filter; said second protection stage being disposed between the measuring connection and said first protection stage; said first protection stage having a first response voltage and said second protection stage having a second response voltage greater than the first response voltage; said third protection stage being connected in parallel with the measuring connection and disposed between the measuring connection and said first protection stage, and said third protection stage includes a mechanical switch for establishing the short circuit if a third response voltage is present.