IP27 vs IP51
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP27 and IP51 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 2 vs 5) and liquid protection (level 7 vs 1). IP27 is rated for > 12.5 mm — finger and temporary immersion (up to 1 m), while IP51 provides dust-protected and vertically dripping water.
The IP27 classification guarantees protection against solid objects larger than 12.5 mm and protection against the effects of temporary immersion in water. Ingress of water in quantities causing harmful effects shall not be possible.. It is an IEC 60529 ingress protection code combining first-digit (solid) level 2 with second-digit (liquid) level 7.
With IP51, an enclosure receives dust-protected (limited ingress, no harmful deposit) and protection against vertically falling drops of water. Dripping water shall have no harmful effects.. It is an IEC 60529 ingress protection code combining first-digit (solid) level 5 with second-digit (liquid) level 1.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP27
2 — > 12.5 mm — Finger
IP51
5 — Dust-Protected
Liquid protection (second digit)
IP27
7 — Temporary Immersion (up to 1 m)
IP51
1 — Vertically Dripping Water
Dust-tight
IP27
No
IP51
Limited
Water-jet resistant
IP27
Yes
IP51
No
Submersible
IP27
Yes
IP51
No
Outdoor suitable
IP27
Yes
IP51
No
The exact difference (IP27 vs IP51)
Solid protection
IP27
Level 2 — > 12.5 mm — Finger
IP51
Level 5 — Dust-Protected
IP27 provides "> 12.5 mm — Finger" (level 2), while IP51 provides "Dust-Protected" (level 5). IP51 is 3 levels higher.
Liquid protection
IP27
Level 7 — Temporary Immersion (up to 1 m)
IP51
Level 1 — Vertically Dripping Water
IP27 handles Hydrostatic ~10 kPa at 1 m (Temporary Immersion (up to 1 m)), while IP51 handles 0.1 mm/min drip rate (Vertically Dripping Water). IP27 provides 6 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
No direct NEMA equivalent.
Recommendation
IP27 offers higher overall protection than IP51. Choose IP27 for harsher environments; IP51 may suffice for milder conditions and can be more cost-effective.