The Guide of the Complementary Technical Instruction ITC-LAT 05 “Verifications and Inspections” sets out that one of the tests to be performed on the regular insulated A.T. wire verifications or inspections is the tests on partial discharges. However, the disadvantage when performing this test is to leave in discharge the line to be analysed. To prevent this, ASPREL has the LPD monitor, a portable system for measuring partial discharges on-line, for monitoring medium and high voltage installations, as seen in MATELEC.
The LPD monitor (Live Partial Discharge monitor) allows to perform a temporal or permanent follow-up of partial discharges at medium and high voltage installations and wires with a rated voltage of up to 66 kV.
The partial discharge signals are received by inductive (HFCT) and/or capacitive sensors (TEV). Therefore, inductive sensors are installed directly around the insulated conductor or the cable shield. Capacitive sensors just join the metal parts of the installations to be tested by magnetic clamping.
See MATELEC and www.asprel.es