Air Circuit Breakers

ACB

Air circuit Breakers are normally used high current operation. ACB current rating 400A, 630A, 800A,1000A, ………………7100A

Normally ACB include following properties.

• 3 , 4 poles ACB
• Microprocessor based.
• Short circuit current rate. (50KA,55KA,65KA….)
• All protection settings including  time setting shall be adjustable
• Ambient temperature
• Breaking Capacity
• Spring charging motor
• Shunt trip coil
• Mechanical Reset button
• Contact point indicator
• Mechanical ON & OFF button

                                                             

                                                                  Air Circuit Breaker

 

 

Earthing System

Earthing System

Panel boards are selling several Countries then earthing systems and main Bus bar arrangement are changed each country.

Type of System Earthing

01.  TN system:

TN power system have one point directly earthed, the exposed conductive parts of the installation being connected to that point by protective conductors. Three types of TN systems are recognized, according to the arrangement of neutral and protective conductors,

(a)    TN-S System – A system having separate neutral and protective conductors throughout

(b)   TN-C-S System – A system in which neutral and protective function are combined in a single conductor in a part of system.

(c)    TN-C system - A system in which neutral and protective functions are combined in a single conductor throughout.

02. TT System -

The TT power system has one point directly earthed, the exposed conductive parts of the installation being connected to earth electrodes electrically independent of the earth electrodes of the power system,

03. IT System  -

The IT power system has no direct connection between live parts and earth, the exposed conductive parts of the electrical installation being earthed.

 

 

Enclosure Mechanical impact resistance

Mechanical impact resistance

An additional number has sometimes been used to specify the resistance of equipment to mechanical impact. This mechanical impact is identified by the energy needed to qualify a specified resistance level, which is measured in joules (J). This has now been superseded by the separate IK number specified in EN 50102.

Although dropped from the 3rd edition of IEC 60529 onwards, and not present in the EN version, older enclosure specifications will sometimes be seen with an optional third IP digit denoting impact resistance. Newer products are likely to be given an IK rating instead. However there is not an exact correspondence of values between the old and new standards.

 

OLD IP Level        Impact energy   Equivalent drop mass and height

0              —           —

1              0.225 J   150 g dropped from 15 cm

2              0.375 J   250 g dropped from 15 cm

3              0.5 J       250 g dropped from 20 cm

5              2 J           500 g dropped from 40 cm

7              6 J           1.5 kg dropped from 40 cm

9              20.0 J     5.0 kg dropped from 40 cm

 

IK

number                Impact energy(joules) Equivalent impact

00           unprotected       no test

01           0.150     drop of 200 gram object from 7.5 cm height

02           0.200     drop of 200 gram object from 10 cm height

03           0.350     drop of 200 gram object from 17.5 cm height

04           0.500     drop of 200 gram object from 25 cm height

05           0.700     drop of 200 gram object from 35 cm height

06           1.00        drop of 500 gram object from 20 cm height

07           2.00        drop of 500 gram object from 40 cm height

08           5.00        drop of 1.7 kg object from 29.5 cm height

09           10.0        drop of 5 kg object from 20 cm height

10           20.0        drop of 5 kg object from 40 cm height

 

IP69K

 

German standard DIN 40050-9 extends the IEC 60529 rating system described above with an IP69K rating for high-pressure, high-temperature wash-down applications.[3] Such enclosures must not only be dust tight (IP6X), but also able to withstand high-pressure and steam cleaning. The test specifies a spray nozzle that is fed with 80°C water at 8–10 MPa (80–100 bar) and a flow rate of 14–16 L/min. The nozzle is held 10–15 cm from the tested device at angles of 0°, 30°, 60° and 90° for 30 s each. The test device sits on a turntable that rotates once every 12 s (5 rpm).

 

The IP69K test specification was initially developed for road vehicles, especially those that need regular intensive cleaning (dump trucks, cement mixers, etc.), but also finds use in other areas (e.g., food industry).

 

NEMA Rating

NEMA enclosure ratings have equivalent IP ingress protection ratings as follows. NEMA enclosure standards also dictate other product features not addressed by IP codes (such as submergibility, operation under icing conditions, and others).

 

NEMA Enclosure               IP Code

4, 4X      IP66

12           IP52

13           IP54

North American enclosure rating systems are defined in NEMA 250, UL 50, UL 508, and CSA C22.2 No. 94.

 

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.