IP45 vs IP51
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP45 and IP51 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 4 vs 5) and liquid protection (level 5 vs 1). IP45 is rated for > 1 mm — small wires and water jets (6.3 mm nozzle), while IP51 provides dust-protected and vertically dripping water.
IP45 protects against 1 mm solid objects and low-pressure water jets (6.3 mm nozzle, 30 kPa). A mid-range indoor/outdoor-covered rating for equipment that may be rinsed or hosed gently.
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)
IP45
4 — > 1 mm — Small Wires
IP51
5 — Dust-Protected
Liquid protection (second digit)
IP45
5 — Water Jets (6.3 mm nozzle)
IP51
1 — Vertically Dripping Water
Dust-tight
IP45
No
IP51
Limited
Water-jet resistant
IP45
Yes
IP51
No
Submersible
IP45
No
IP51
No
Outdoor suitable
IP45
Yes
IP51
No
The exact difference (IP45 vs IP51)
Solid protection
IP45
Level 4 — > 1 mm — Small Wires
IP51
Level 5 — Dust-Protected
IP45 provides "> 1 mm — Small Wires" (level 4), while IP51 provides "Dust-Protected" (level 5). IP51 is 1 level higher.
Liquid protection
IP45
Level 5 — Water Jets (6.3 mm nozzle)
IP51
Level 1 — Vertically Dripping Water
IP45 handles 30 kPa (Water Jets (6.3 mm nozzle)), while IP51 handles 0.1 mm/min drip rate (Vertically Dripping Water). IP45 provides 4 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP45 offers higher overall protection than IP51. Choose IP45 for harsher environments; IP51 may suffice for milder conditions and can be more cost-effective.