IEC 60230-2018 pdf free.lmpulse tests on cables and their accessories.
6Lightning impulse voltage
The peak voltage level of the lightning impulse is specified in the relevant product standard orcontractual agreements.The lightning impulse voltage to be applied shall be a standardlightning-impulse voltage as specified in lEC 60060-1 with the exception that the front time T1shall be between 1 us and 5 us.
7 Switching impulse voltage
The peak voltage level of the switching impulse is specified in the relevant product standard.
The switching impulse voltage to be applied shall be a standard switching impulse voltage asspecified in lEC 60060-1.
8 superimposed impulse voltage test
8.1General
The superimposed impulse voltage test shall be carried out on HVDC cable systems. Thepeak voltage level of the switching impulse is specified in the relevant product standard.
When a superimposed impulse voltage test is required, Clause 8 shall be applied in additionto the other clauses of this document.
8.2Test setup
Some possibilities are given to apply an impulse voltage to a test object which is at the sametime energized by a Dc voltage; Annex C illustrates the possible superimposed impulse testcircuit arrangements.
8.3Time parameters
The time parameters shall meet the requirements of Clause 6 or Clause 7 and shall bedetermined with the DC voltage source set to zero output or disconnected，i.e. withoutenergizing the test object by a DC voltage and with the spark gap (as applicable)short-circuited.Once the time parameters have been determined, there shall be no changesto the test setup other than connecting the DC voltage source and removing the short-circuitacross the spark gap.
The time parameters are to be determined in this way because a base level around 0 kV isrequired by lEC 60060-1.
8.4Application of the Dc voltage
Before the impulses are applied to the test object，if required，the test object shall beenergized by a DC voltage with a level and duration and polarity as specified in the productstandard.
The application of the impulses is given in Clause 10.
9Measuring system
The preferred method to measure the impulse voltage is by using an approved measuringsystem according to lEC 60060-2.
Alternatively，the method described in Annex B may be used at the discretion of themanufacturer.
10 Application of the impulses
Both ends of the test object shall be connected to the impulse generator (via the spark gap orblocking capacitor in the case of a superimposed impulse test).IEC 60230 pdf download.