⚡ Surge immunity — combination wave generator 1.2/50 µs and 8/20 µs, up to 4 kV

Electronics and EMC PN-EN 61000-4-5

Overview

The standard relates to testing the immunity of electrical and electronic equipment to high-energy surges, representing the effects of lightning and switching in the supply network. The recommended test levels of open-circuit voltage, with a tolerance of ±10 %, are 0.5 kV, 1.0 kV, 2.0 kV and 4.0 kV; level "x" is not specified and may be given in the technical requirements of the product. The levels are selected depending on the installation conditions, and the installation classes are given in Annex B of the standard. The immunity requirements must be met at all voltages of the lower test levels.

The standard provides two generators. The combination wave generator, called hybrid, delivers a 1.2/50 µs voltage surge under open-circuit conditions and an 8/20 µs current surge under short-circuit conditions, with the voltage adjustable at least in the range from 0.5 kV to 4.0 kV; the short-circuit current is a minimum of 0.25 kA at a set open-circuit voltage of 0.5 kV and a minimum of 2.0 kA at 4.0 kV. The second generator, intended for telecommunication lines, delivers a 10/700 µs surge in the same voltage range, with a current of a minimum of 100 A for an open-circuit voltage of 4.0 kV.

The recommended test strategy consists of first checking the operation of the equipment at a low test level, for example 0.5 kV or 1 kV, and then testing at a higher level, for example 2 kV or 4 kV. Polish accredited laboratories carry out this test on single- and three-phase power ports, DC power ports and on input and output lines.

Method principle

The combination wave generator produces a surge whose waveform depends on the load impedance: under open-circuit conditions it is a 1.2/50 µs voltage waveform, and under short-circuit conditions an 8/20 µs current waveform; the generator has a specified effective output impedance. Surges are applied between the line conductors or between a line conductor and earth; when testing between line and earth the test voltage is applied successively between each line conductor and earth, unless otherwise specified. In the absence of other requirements, surges are generated synchronously with the phase of the AC voltage: at the zero crossing and at the peak value of the waveform, positive and negative. At least five positive and five negative surges are applied at the selected points, at a repetition rate of no more than one surge per minute, because the protective elements of the equipment under test have a low average power dissipation.

Applications

• Immunity testing of power supplies, controllers and industrial equipment against mains overvoltages
• Assessment of the effectiveness of built-in surge protective devices
• Testing of telecommunication lines with the 10/700 µs generator
• Compliance testing of products with the electromagnetic compatibility directive
• Acceptance testing of apparatus powered from the low-voltage network in accredited laboratories

Key parameters

Standard

Standard number

PN-EN 61000-4-5:2014-10

Title (PL)

Kompatybilność elektromagnetyczna (EMC) — Część 4-5: Metody badań i pomiarów — Badanie odporności na udary

Title (EN)

Electromagnetic compatibility (EMC) — Part 4-5: Testing and measurement techniques — Surge immunity test

Step-by-step procedure

1. Selection of the test level

   Select the level depending on the installation conditions, using the installation classes from Annex B of the standard; the immunity requirements must also be met at all voltages of the lower levels.

2. Test plan

   In the plan specify the test setup, the generator and other equipment, the voltage and current test levels, the internal impedance of the generator, the surge polarity, the triggering method, the number of tests, the repetition rate, the inputs and outputs tested, representative operating conditions of the equipment, the sequence of surges, the phase angle and the actual installation conditions, for example an earthed neutral conductor in an AC network or an earthed positive or negative pole in a DC network.

3. Calibration of the generators

   Check the characteristics and technical parameters of the generators and calibrate them in accordance with the relevant clauses of the standard: the voltage waveform in open circuit and the current waveform in short circuit.

4. Setting up the test bench

   Connect the generator to the equipment under test through the coupling/decoupling network, in accordance with the port tested and the method of applying the surge.

5. Preliminary test at a low level

   Check the operation of the equipment under test at a low test level, for example 0.5 kV or 1 kV, to confirm the correctness of the setup and the behaviour of the equipment before exposure to the full level.

6. Application of surges

   Apply at least five positive and five negative surges at each selected point, at a rate of no more than one per minute. With AC supply, trigger the surges at the zero crossing and at the positive and negative peak value.

   ⏱ Time: interval min. 1 min

7. Line-to-earth test

   When testing between line and earth, apply the test voltage successively between each line conductor and earth, unless otherwise specified.

8. Assessment and report

   Assess the operation of the equipment according to the performance criteria from the product requirements. In the report state the generator, levels, polarities, phase angles, number and rate of surges, ports tested and the result.

Required equipment and apparatus

Health and safety (OHS)

• Surges with a voltage of up to 4 kV and a short-circuit current of up to 2 kA — enclosed test bench, interlocks, no access to the terminals during exposure
• The surge energy is sufficient to damage equipment and cause electric shock — operation only by trained personnel
• The equipment under test remains at mains voltage during the test — protection against electric shock and an emergency stop
• Protective elements in the equipment under test may overheat with too frequent surges — keep an interval of at least one minute
• Discharge the capacitive circuits of the generator before any intervention in the connections

Frequently asked questions