Why do inductors also have safety distance requirements？

In fact, for the general circuit, the inductor has no clear requirements for the safety distance, and only needs to meet the basic voltage insulation requirements, and the product will not short circuit after working for a long time.

 When testing in inductance, we often test the windings' resistance to winding, or the winding's resistance to the magnetic core, which is generally around 500VAC.

                                                        FKS NiZn Common Mode Power Line Choke

However, if electroinduction is used in high-voltage circuit scenarios, it will be different. In high-voltage circuits, the spacing between inductor pins often needs to meet the standards of electrical clearance and creepage distance to avoid short circuits or discharges.

 According to the IEC60950 standard, different voltage levels correspond to different minimum distances. If the 400V voltage circuit is not slotted, the electrical gap between the inductor pins must be ≥6.4mm. In terms of creepage distance, for 220V circuits, the FR4 substrate creepage distance needs to be ≥4.0mm, for high-voltage inductors, such as inductors next to the main transformer of the switching power supply, the strengthening insulation distance needs to be ≥8.0mm.

When the operating temperature of the inductor is relatively high, the safety distance can also be appropriately increased to compensate for the aging of the insulation material caused by the long-term use of the inductor.

                                            FKS Common Mode Power Line Choke

In the circuit design process, if the creepage distance is insufficient, it can also be met by grooving. For the selection of inductance materials, it is necessary to use fire retardant skeleton, high temperature resistant enamelled wire and safety certified insulation tape to ensure compliance with safety standards and requirements.

 In general, the inductive safety distance requirement is essentially to prevent the safety risks caused by electrical breakdown, leakage and insulation failure. This piece can refer to IEC 60950, UL 60950 and other standards, combined with voltage level, working environment and material characteristics comprehensive design, to ensure that the test certification.