CABLES AND WIRES - Novkabel

Tests of cables after layingTesting of dielectric strength of insulationAfter laying of cables and before backfilling of the route, it is necessary to conduct the testingof dielectric strength.The testing could be carried out by DC or AC voltage of industrial frequency.Insulation type PVC XLPE, EPRTesting voltageNominal voltageU O /UDirect Alternating Direct AlternatingAlternatingPhase15 minutes 15 minutes 5 minutes 24 hourskV kV kV kV kV kV0,6/1 4,5 2,5 6 1 0,63,6/6 14,5 7,5 18 6 3,66/10 24 10,5 25 10 612/20 - - 50 20 1220/35 - - 84 35 20The values in the table are given in accordance with the requirements of SRPS N.C5.225 andSRPS N.C5.235 standards.Testing after the reparation of a cableAfter being repaired, the cable can be tested by:- direct voltage of 2,5 U O /15 minutes or- alternating voltage of 1,5 U O /15 minutes.Testing of outer sheathTesting of the outer sheath after laying is recommendable. The aim of this test is to check thevalidity of the sheath, since its damage during installation can allow water penetration in thecable that can result in adverse consequences.In accordance with SRPS N.C5.225 standard, the sheath can be tested by direct voltage of 5kV/5 minutes.239