Procedure to apply IEC 61000-4-4 bursts test

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Appendix E

Procedure to apply IEC 61000-4-4 bursts test

To perform fast transient voltage tests in compliance with EN61000-4-4 specifications on

thermostat boards connected to a compressor, a 15W light bulb and a 25W defrost resistor,

we have implemented the arrangements shown in Figure 18. These arrangements ensure

very stressful tests, but still comply with EN61000-4-4 specifications. These main

arrangements are:

●

Thermostat Board, loads and mains wires are placed 10 cm above the ground

reference.

●

The mains wire is shorter than 1m.

●

The compressor protective earth is linked to the PE of the board through a 30cm cable.

Figure 18.

EN61000-4-4 test layout

Each operating cycle has been tested (all loads OFF, lamp ON, Motor ON, lamp + motor

ON). The burst withstanding level is in the range from 2.3kV to more than 4.5kV (maximum

capability of our generator) depending on the coupling mode (to L, N, PE, etc.).