How do I know if an enclosure will protect my equipment against fire or excess heat?

Enclosures are tested against glow wire standards under the IEC 60695-2-11 series, which model what happens when overloaded connections or overheating components cause a fault.

Glow wire testing is an indirect-flame method: a heated wire is applied to a test sample for 30 seconds, with tissue paper positioned underneath to check for dripping. It measures how well a material resists ignition, whether it self-extinguishes, and whether it drips burning material.

To pass, load-bearing parts near live components must not burn or glow when exposed to a wire heated to roughly 960°C (tolerance depends on the material), any residual glow must go out within 30 seconds of the heat source being removed, and no falling debris should ignite the tissue paper below. This testing regime is what underpins confidence in an enclosure’s fire performance during a real fault condition.