Type Test required for ASTA certification TTA

Type test will be carried out on a sample of such an ASSEMBLY or on such parts os ASSEMBLIES manufactured to the same or similar design.

Type tests include the following:

1. verification of temparature rose limits (8.2.1)
2. verification of the dielectric properties (8.2.2)
3. verification of the short-circuit withstand strength (8.2.3)
4. verification of the effectiveness of the protective circuit (8.2.4)
5. verification of the clearences and  creepage distances (8.2.5)
6. verification of the mechanical operation (8.2.6)
7. verification of the digree of protection (8.2.7)
8. EMC tests ( see 7.10cand, if applicable )

There  test may carried out in any order and /or on different sample of the same type

If  modifications are made to the components of the ASSEMBLY, new type tests have to be carried out only in so far as such modifications are likely to adversely affect the results of these tests.

Testing to DIN EN 60439-1

For a safety function of low-voltage switchgear com
binations it is necessary to match the different features of the individual components - the technical details to be considered are described in standard IN EN 60439-1(“Low-voltage switchgear combinations; part 1: Type-tested and partially type-tested assemblies“).

The proof of requirements for fulfilling the basic legal principles for low-voltage switchgear assemblies may be provided in line with the declaration of conformity and CE labelling by applying the standard mentioned above. The manufacturer must observe the relevant standards at the planning stage as well as in manufacturing, assembly and plant documentation.

Type-tested (TTA) and Partially type-tested assemblies (PTTA)

Type-tested assemblies (TTA)

No.	Requirement to be tested	TTA
1	Overtemperature limit	Proof of overtemperature limit by testing (type testing)
2	Insulation	Proof of insulation by testing
3	Short-circuit resistance	Proof of short-circuit resistance by testing (type testing)
4	Effectiveness of the PE conductor circuit Proof of the perfect connection between bodies, switchgear assemblies and PE conductor circuits Short-circuit resistance of the PE conductor circuit	Proof of the perfect connection between bodies of the switchgear assembly and PE conductor circuit (type testing) Proof of the short-circuit resistance of the PE conductor by testing (type testing)
5	Creepage distances and clearances	Proof of creepage distance and clearances (type testing)
6	Mechanical function	Proof of mechanical function (type testing)
7	IP protection category	Proof of IP protection category (type testing)
8	Wiring, electrical function	Viewing of switchgear assemblies including wiring and electrical function testing if necessary (unit testing)
9	Insulation	Insulation testing (unit testing)
10	Protective measures	Checking of protective measures and continuous PE conductor circuits (unit testing)
11	Insulation resistance	Proof of insulation resistance if test was not carried out

Partially type-tested assemblies (PTTA)

No.	Requirement to be tested	PTTA
1	Overtemperature limit	Proof of compliance with overtemperature limit by testing or extrapolation
2	Insulation	Proof of insulation by testing or proof of insulation resistance
3	Short-circuit resistance	Proof of short-circuit resistance by testing or extrapolation of similar type-tested assemblies
4	Effectiveness of the PE conductor circuit Proof of the perfect connection between bodies, switchgear assemblies and PE conductor circuits Short-circuit resistance of the PE conductor circuit	Proof of the perfect connection between bodies of the switchgear assembly and PE conductor circuit Proof of the short-circuit resistance of the PE conductor circuit by testing or respective design and arrangement of the PE conductor
5	Creepage distances and clearances	Proof of creepage distance and clearances
6	Mechanical function	Proof of mechanical function
7	IP protection category	Proof of IP protection category
8	Wiring, electrical function	Viewing of switchgear assemblies including wiring and electrical function testing if necessary
9	Insulation	Insulation test or proof of insulation resistance
10	Protective measures	Checking of protective measures
11	Insulation resistance	Proof of insulation resistance if test was not carried out

NEMA Enclosure Types

The purpose of this document is to provide general information on the definitions of NEMA Enclosure Types to architects, engineers, installers, inspectors and other interested parties.  [For more detailed and complete information, NEMA Standards Publication 250-2003, “Enclosures for Electrical Equipment (1000 Volts Maximum)” should be consulted.  This Standards Publication as well as all other NEMA publications are available from IHS @ 800 854-7179 or http://www.global.ihs.com]

Definitions[from NEMA 250-2003]

In Non-Hazardous Locations, the specific enclosure Types, their applications, and the environmental conditions they are designed to protect against, when completely and properly installed, are as follows:

Type 1        Enclosures constructed for indoor use to provide a degree of protection to personnel against access to hazardous parts and to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt).

Type 2        Enclosures constructed for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing).

Type 3        Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and that will be undamaged by the external formation of ice on the enclosure.

Type 3R     Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and that will be undamaged by the external formation of ice on the enclosure.

Type 3S     Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); and for which the external mechanism(s) remain operable when ice laden.

Type 3X     Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); that provides an additional level of protection against corrosion and that will be undamaged by the external formation of ice on the enclosure.

Type 3RX  Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); that will be undamaged by the external formation of ice on the enclosure that provides an additional level of protection against corrosion; and that will be undamaged by the external formation of ice on the enclosure.

Type 3SX   Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow); that provides an additional level of protection against corrosion; and for which the external mechanism(s) remain operable when ice laden.

Type 4        Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow, splashing water, and hose directed water); and that will be undamaged by the external formation of ice on the enclosure.

Type 4X     Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (windblown dust); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (rain, sleet, snow, splashing water, and hose directed water); that provides an additional level of protection against corrosion; and that will be undamaged by the external formation of ice on the enclosure.

Type 5        Enclosures constructed for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and settling airborne dust, lint, fibers, and flyings); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing).

Type 6        Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (hose directed water and the entry of water during occasional temporary submersion at a limited depth); and that will be undamaged by the external formation of ice on the enclosure.

Type 6P     Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (hose directed water and the entry of water during prolonged submersion at a limited depth); that provides an additional level of protection against corrosion and that will be undamaged by the external formation of ice on the enclosure.

Type 12      Enclosures constructed (without knockouts) for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and circulating dust, lint, fibers, and flyings); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing).

Type 12K   Enclosures constructed (with knockouts) for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and circulating dust, lint, fibers, and flyings); and to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing).

Type 13      Enclosures constructed for indoor use to provide a degree of protection to personnel against access to hazardous parts; to provide a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and circulating dust, lint, fibers, and flyings); to provide a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing); and to provide a degree of protection against the spraying, splashing, and seepage of oil and non-corrosive coolants.

Index of Protection - IP rating of Enclosure

Specification for degrees of protection provided by enclosures.

The IP number consists of two numbers, the first of which describes the protection against solid bodies, and the second describes the protection given against liquids.

1st IP number	Protection against Solid Bodies
0	No protection from solid bodies is provided.
1	Enclosure provides protection from objects larger than 50 mm. e.g. contact with hand.
2	Enclosure provides protection from objects larger than 12 mm. e.g. contact with finger.
3	Enclosure provides protection from bodies larger than 2.5mm. e.g. contact with wires.
4	Enclosure provides protection from bodies larger than 1mm. e.g. contact with fine wires.
5	Enclosure provides protection from harmful levels of dust.
6	Enclosure provides total protection from dust.

2nd IP number	Protection against Liquid
0	No protection from liquid provided.
1	Enclosure provides protection from vertically falling water only.
2	Enclosure provides protection from water falling at up to 15° from vertical.
3	Enclosure provides protection from water falling at up to 60° from vertical.
4	Enclosure provides protection from water splashed from all directions.
5	Enclosure provides protection from low pressure water jets
6	Enclosure provides protection from high pressure water jets.
7	Enclosure provides protection from temporary submersion in water, up to 1 meter in depth.
8	Enclosure provides protection from extended periods of immersion, up to a specific depth.

IEC 60439-1 / EN 60439-1

Type-tested low-voltage switchgear and controlgear assembly (TTA) A low-voltage switchgear and controlgear assembly conforming to an established type or system without deviations likely to significantly influence the performance, from the typical ASSEMBLY verified to be in accordance with this standard. IEC 60439-1 / EN 60439-1;2.1.1.1. Partially type-tested low-voltage switchgear and controlgear assembly (PTTA) A low-voltage switchgear and controlgear assembly, containing both type-tested and non-type-tested arrangements provided that the latter are derived (e.g. by calculation) from type-tested arrangements, which have complied with the relevant tests. IEC 60439-1 / EN 60439-1; 2.1.1.2.

 

 

What is the Electrical Panel?

An electrical enclosure is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment. The enclosure is the only part of the equipment which is seen by users; in many cases it is designed not only for its utilitarian requirements, but also to be pleasing to the eye.

In the United States, the National Electrical Manufacturers Association publishes standards for the performance of various classes of electrical enclosures. The NEMA standards cover corrosion resistance, ability to protect from rain and submersion, etc. For IEC member countries, standard IEC 60529 is classifying the ingress protection rating (IP Codes) of enclosures.

Electrical enclosures are usually made from rigid plastics, metals, particularly steel and aluminum, and natural or processed wood. They may be made for a specific purpose (e.g., the metal, plastic, or wooden box of a particular radio receiver) or to accommodate any equipment to which they are suited.

Enclosures for some purposes have partially punched openings (knockouts) which can be removed to accommodate cables, connectors, or conduits. Where they are small and primarily intended to conceal electrical junctions from sight, or protect them from tampering, they are also known as junction boxes, street cabinets or technically as serving area interface.