IP rating; fittings, cables and connectors

An IP or Ingress Protection rating is a measurement of permissible intrusion of solid objects and liquid within an outer casing or electrical enclosure. It is a means of avoiding vague descriptions like 'waterproof' and providing a detailed explanation of how resistant to ingress the product is.


The first digit indicates protection offered against solid objects; 0 being the lowest, offering no protection and 6 being the highest, offering protection against ingress from dust particles.


The second digit indicates the protection against liquid. Again 0 is the lowest level, affording no protection against water ingress and 8 being the highest, allowing for immersion in water beyond 1m in depth. Full descriptions of all the ratings available here.


Our standard outdoor fittings are generally rated at IP65 (protection against ingress from dust and water jets) or IP66 (protection against ingress from dust and powerful water jets).


An important fact about ingress protection that is often overlooked is the integrity of the whole system. In practical terms, if an IP66 fitting is connected to its supply using connectors of a lower IP rating, for example terminal block, then this will become the weakest link in the chain and effectively negate the IP66 rating. Cables, when not correctly terminated can act as 'straws' and draw water into an otherwise sealed fitting via capillary action.