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Electrical Enclosure Ingress Protection Ratings Overview

The majority of electrical enclosure testing is conducted to one of four ingress protection test standards. The first is IEC 60529. The second is NEMA 250 and the third and fourth are UL 50 and UL 50E. Each of these testing standards has a definition of protection. NEMA 250 and the UL standards also outline design requirements.

This page covers both the Electrical Enclosure Ingress Protection Requirements as well as the Electrical Enclosure Design Requirements. These are essential components to the enclosure IP Code. These are also called electrical case ratings.

Ingress Protection Requirements of Electrical Enclosures

IEC 60529 ingress protection testing is also called IP Code testing. The testing focuses on the degree of protection an enclosure provides against solids and liquids. The IP Code is a two-number combination. The first number is the degree of protection from solid objects. This can include protection ratings including protection against dust.

The second number is the degree of protection from liquids. The chart below shows the IP Code ratings.

IP Rating

Size of Object Protected Against

Examples of Objects Protected Against

IP 0X

No protection

None

IP 1X

> 50 mm

Large surface of body, but not deliberate contact (back of hand vs finger)

IP 2X

> 12.5 mm

Smaller objects and fingers

IP 3X

> 2.5 mm

Thick wires or tools

IP 4X

> 1 mm

Screws, nails, wires

IP 5X

Dust protected

Some dust may enter, but cannot interfere with operation

IP 6X

Dust tight

No ingress of dust at all

The NEMA 250 test standard specifies the level of ingress protection. It also speaks to the minimum enclosure design requirements. Regarding the level of ingress protection, the electrical enclosure testing involves determining protection from solids and liquids.

Instead of an IP Code rating like IEC 60529, NEMA 205 testing provides an enclosure rating. This rating is important to national electrical manufacturers. It specifies the NEMA type and testing and certification. The chart below shows the enclosure ratings and the protection requirements of those ratings.

Type

Solid

Liquid

Type 1

Falling dirt

No protection

Type 2

Falling dirt

Dripping and light splashing water

Type 5

Falling dirt, settling airborne dust, fibers, flyings and lint

Dripping and light splashing water

Type 12

Falling dirt, circulating dust, fibers, flyings and lint

Dripping and light splashing water; seepage and light splashing of oil and non-corrosive coolants

Type 13

Falling dirt, circulating dust, fibers, flyings and lint

Dripping and light splashing water; seepage, light splashing and spraying of oil and non-corrosive coolants

Type 3

Windblown dust and falling dirt

Water from sleet, snow and windblown rain

Type 3R

Falling dirt

Water from falling rain, sleet and snow

Type 4

Windblown dust and falling dirt

Water directed from a hose or from rain, sleet, snow and splashing water

Type 4X

Windblown dust and falling dirt

Water directed from a hose or from rain, sleet, snow and splashing water; increased corrosion protection

Type 6

Falling dirt

Hose directed water and submersion that is temporary and at a limited depth

Type 6P

Falling dirt

Hose directed water and submersion that is prolonged and at a limited depth

It should be noted NEMA 250 Types 1, 2, 5, 12 and 13 are for indoor use only. All other types can be indoor or outdoor. The NEMA electrical enclosure rating is often used for marketing. Cases that meet the electrical enclosure water test and have electrical enclosure certification are required for many applications.

UL 50 is similar to NEMA 250 in that it stipulates levels of protection and design criteria. It is essentially an electrical case IP Code. The chart below specifies the levels of protection from solids and liquids for each enclosure type.

Type

Solid

Liquid

Type 1

Falling dirt

No protection

Type 2

Falling dirt

Dripping and light splashing of non-corrosive liquids

Type 5

Falling dirt, settling airborne dust, fibers, flyings and lint

Dripping and light splashing of non-corrosive liquids

Type 12

Falling dirt, circulating dust, fibers, flyings and lint

Dripping and light splashing non-corrosive liquids; seepage and light splashing of oil and non-corrosive coolants

Type 13

Falling dirt, circulating dust, fibers, flyings and lint

Dripping and light splashing non-corrosive liquids; seepage, light splashing and spraying of oil and non-corrosive coolants

Type 3

Windblown dust and falling dirt

Water from rain, sleet and snow

Type 3R

Falling dirt

Water from rain, sleet and snow

Type 4

Windblown dust and falling dirt

Water directed from a hose or from rain, sleet, snow and splashing water

Type 4X

Windblown dust and falling dirt

Water directed from a hose or from rain, sleet, snow and splashing water as well as corrosion protection

Type 6

Falling dirt

Hose directed water and occasional submersion that is temporary and at a limited depth

Type 6P

Falling dirt

Hose directed water and prolonged submersion at a limited depth

Design Requirements for Electrical Enclosures

As previously mentioned, only the NEMA 250 enclosure testing standard and UL 50 and UL 50E enclosure testing standards outline the design requirements for enclosures of electrical equipment. These standards cover a number of enclosure characteristics and how they protect against harmful effects.

These include finish, flammability, latching, material, mounting, sealing, strength, thermal and ventilation. The UL standards have additional requirements for bonding and grounding that the NEMA 250 tests do not. It is important that a short circuit or branch circuit does not occur.

When reviewing the design of an enclosure, here are some of the items a UL 50 and NEMA 250 test lab will be researching:

  • Does the enclosure ensure operator safety?
  • Is the equipment protected?
  • Will the enclosure perform in extreme temperatures and atmospheres?
  • Does the enclosure provide sufficient UV protection?
  • Are the doors and covers properly sealed?
  • Does the enclosure adequately prolong the life of the equipment?
  • Is the enclosure corrosion resistant?
  • Is the enclosure easy to access, install and repair?

Keystone Compliance is recognized as one of the best ingress protection testing labs in the country. Our capabilities and expertise allow us to meet nearly every ingress protection test requirement. Some of the more common enclosures we test are NEMA 4X, NEMA 12, IP66 electrical enclosures and IP68 electrical enclosures. In addition to NEMA

Contact us to learn firsthand why so many companies partner with Keystone Compliance to meet their electrical enclosure test lab needs.