Safety: Top 10 design review misses

Most safety failures aren’t “exotic.” They’re the result of small architectural gaps that become expensive late. Here are 10 common misses we see before certification.

The top 10

• 1) Creepage/clearance surprises: spacing not maintained after layout revisions.
• 2) Protective earth strategy unclear: what bonds to PE, how, and where continuity is ensured.
• 3) Insulation system not defined: materials and insulation classes not controlled.
• 4) Fusing/protection not coordinated: protection components don’t match fault assumptions.
• 5) Temperature rise ignored early: hotspots discovered late with final enclosure.
• 6) Abnormal conditions not planned: stalls, shorts, blocked vents, wrong inputs.
• 7) Labeling + markings incomplete: ratings, warnings, and symbols missing/incorrect.
• 8) Power supply assumptions: external PSU selection doesn’t match end standard needs.
• 9) Accessibility issues: openings, touch temperatures, sharp edges, mechanical hazards.
• 10) Evidence gaps: requirements exist, but traceability and rationale are missing.

What to do next

Put safety checks into design gates. If a requirement affects enclosure, layout, wiring, or materials, it should be locked before “final prototype.”