IEC 63294-2021 Test methods for electric cables with rated voltages up to and including 450/750 V.
5.2 Voltage test carried out on completed cables A sample of cable as delivered shall be immersed in water. The length of the sample, the temperature of the water and the duration of immersion and the test voltage shall be given in the relevant cable standard. A voltage shall be applied in turn between each conductor and all the others together, connected to the metallic layer or metallic component, if any, or to the water; and then between all conductors together and the metallic layer or metallic component, if any, or to the water. No breakdown of the insulation shall occur during the test.
5.3 Voltage test on cores in water
5.3.1 General The test applies to sheathed cables, braided cables and flat non-sheathed cables.
5.3.2 Test sample Prepare a sample of cable 5 m long, by carefully removing, without damaging the cores, the sheath or the overall braid and any other covering or fillers from a length of completed cable. In the case of a flat non-sheathed cable, take a 5 m sample and make a cut in the insulation between the cores and separate the cores by hand over a length of 2 m, without damaging the cores.
5.3.3 Procedure Immerse the sample in water at the temperature, and for the period specified in the relevant cable standard. Ensure that the ends of the cores protrude above the water by a distance sufficient to prevent excessive surface leakage when the test voltage is applied. Apply a voltage between the conductors and the water, of the magnitude and for the time specified in the relevant cable standard.
5.3.4 Requirements No breakdown of the insulation shall occur during the test.
5.4 Insulation resistance This test shall be made on the core samples, 5 m in length, previously submitted to the test described in 5.3 or, if this is not applicable, to the test described in 5.2. The sample shall be immersed in water previously heated to the temperature indicated in the relevant cable standard. A length of about 0,25 m at each end of the sample shall be kept above the water. The length of the samples, the temperature of the water and the duration of immersion shall be given by the relevant cable standard. A DC voltage of between 80 V and 500 V shall then be applied between the conductor and the water. The insulation resistance shall be measured 1 min after application of the voltage. The measured value shall be expressed in MΩ · km.IEC 63294 pdf download.