How can a smart controller (PAC) suppress lightning strikes and electrical fast transients?

Suppressing lightning strikes and electrical fast transients (EFTs) in a PAC (Power Arrangement Controller) requires multi-level protection. For lightning surges, a varistor (14D511K) or gas discharge tube (2R600L-8×6) is used as the first level at the power input, and a TVS (5.0SMDJ36CA) as the second level. For EFTs, a common-mode inductor (CMZ7060A-701T) and X/Y capacitors are used for filtering. The signal ports are similar, but attention must be paid to the response speed of the protection devices. All protection devices should have short and thick grounding paths.

During testing, lightning strikes are tested according to IEC61000-4-5 Level 4 (4kV), and EFTs are tested according to IEC61000-4-4 Level 4 (4kV). The system should not be damaged and its function should be self-recovering. After suppression, the PAC can withstand harsh industrial environments and has a lifespan of more than 10 years.