Introducing IEC-61439-3PD

IEC 61439

An introduction 28 March 2012

By Craig McKee

Technical Manager

We recommend that you purchase your relevant national

standard, or the International Standard which is available

directly from the IEC.

This training expresses the interpretation and opinions of 3 Phase Design

•Part 1: General Rules

•Part 2: PSC – Assemblies

•Part 3: Distribution boards

•Part 4: Assemblies for Construction Sites (not launched)

•Part 5: Assemblies for power distribution

•Part 6: Busbar trunking systems (pre release available)

•Part 7: Assemblies for use in marinas and similar locations, camping

sites and similar locations, market squares and other similar

external public sites (not launched)

IEC 61439:- The Series

•Part 1: General Rules

•Part 2: PSC – Assemblies

•Part 3: Distribution boards

•Part 4: Assemblies for Construction Sites

•Part 5: Assemblies for power distribution

•Part 6: Busbar trunking systems

•Part 7: Assemblies for use in marinas and similar locations, camping

sites and similar locations, market squares and other similar external

public sites

IEC 61439:- The Series

General Rules

Cross referenced by all other parts of the series.

Does not need to be specified, compliance to one of the other

parts of the standard automatically determines its compliance.

61439-Part 1 Edition 2 - 2011

Power Switchgear and Controlgear Assemblies.

“low – voltage switchgear and controlgear assembly used

to distribute and control energy for all types of loads,

intended for industrial, commercial and similar applications

operated by skilled or instructed persons”

61439-Part 2 Edition 2 - 2011

Enclosure

Earth Bar (protective conductor)

Incoming Device

• Air Circuit Breaker (ACB)

• Moulded Case Circuit Breaker (MCCB)

• Isolator

Busbars

• Main

• Distribution

Outgoing Devices

• Circuit Breakers (MCB, MCCB)

• Fused Isolators

• Additional power circuits

Auxiliary circuits (controls)

What is an assembly?

Design Verification

Performed on representative samples and designs

Routine Verification

Performed on every supplied assembly – by checking against Design Verification

Complying with the standard

The Standard recognises that there maybe more than one

company responsible for the verification of the final assembly.

• Original Manufacturer

• Assembly Manufacturer

Who is responsible for verification?

•Design Production

•Design Verification (By Test)

Original Manufacturer

•Manufacture to Design

•Design Verification

•Routine Verification

Original & Assembly

Manufacturer

•Manufacture to Design

•Routine Verification

Assembly Manufacturer

Who is responsible for verification?

•Verification by test

•Verification by Comparison with a reference design

•Verification by Assessment

Not all characteristics can be verified by each of the above in all

circumstances.

Table D. 1. For example, Lifting can only be verified by test

Achieving design verification

Construction

•Strength of materials and parts

•Degree of protection of enclosures

•Clearances and creepage distances

•Protection against electric shock and integrity of protective circuits

•Incorporation of switching devices and components

•Internal electrical circuits and connections

•Terminals for external conductors

Performance

•Dielectric properties

•Temperature rise limits

•Short circuit withstand strength

•Electromagnetic compatibility

•Mechanical operation

Design verification characteristics

Construction








Performance







Construction


• Protection against corrosion

• Properties of insulating materials

• Normal heat

• Abnormal heat

• Resistance to UV radiation

• Lifting

• Mechanical strength

• Marking

Strength of Materials & Parts

Construction








Performance







Construction



IEC 61439 clarifies that there is a difference between

Constructional Requirements and internal separation.

Form of separation does not specify the construction

If each functional unit is to be contained in its own

compartment – That is what should be stated.

Internal separation of assemblies

Construction








Performance







Construction








Performance







Construction








Performance







Construction








Performance







Construction








Performance







Construction








Performance







Construction








Performance







Assemblies are now rated for there operational current and each

circuits is also assigned a rating.

Rated current

• Of a circuit (Inc)

• Of the Assembly (InA)

Temperature rise limits

There are 3 options to achieving the assembly rating by test:

•Verification by test option a: (10.10.2.3.5)

•Verification by test option b: (10.10.2.3.6)

•Verification by test option c: (10.10.2.3.7)

Temperature Rise InA

•Device to IEC 60947

Temperature Rise Inc


•Mounted in enclosure




•Circuit reaches limits at <100%


XX Amps



•Circuit reaches limits at <100%

•Disclosed rating Inc = XX Amps

•This rating is the MAXIMUM allowable current for that circuit design


•The RDF may only be applied to outgoing circuits, there can be

more than one RDF applied within a single assembly.

•The RDF is applied to the Inc rating

•The RDF shall not be applied to incoming circuits or the busbars

Rated Diversity Factor

Temperature Rise Test Connections

Image taken at

As well as verification by test there are other methods of verification:

Derivation of ratings for similar values

This can only be performed from a tested design

Assessment – based on design rules.

This can only be done on single compartment assemblies below 630Amps

Assessment – based on design rules and IEC 60890

On a single or multiple compartment assembly below 1600A

Temperature rise limits

Construction








Performance







Short circuit tests

• (Icw) Withstand test on main incoming device & busbar system

• (Icc) Short circuit test on both incoming and outgoing devices

• (Icc) Phase to Earth short circuit on outgoing devices

Short circuit withstand strength

Short Circuit Test Connections

Construction








Performance







Construction








Performance







On successful completion of the above design verifications the

original manufacturer will be issued with a certificate.

But that is not the end of the story…


...every assembly is required to pass through a routine

verification process.

This process ensures that all production assemblies are still in

compliance to the design verified assembly that was certified,

with any modifications being accounted for.

Routine verification requirements

Construction







•Mechanical Operation

Performance


•Wiring, operational performance and function

Routine verification characteristics

Routine verification characteristics

Why does a manufacturer need to carry out routine verification?

• Ensure the equipment remains compliant with IEC 61439

• Reduces the risk of failure on production assemblies

• Puts the onus onto the manufacturer for continued quality

As a customer what should I ask for?

• An inspection of the complete design verification document

• A list of any deviations from the verified assembly

• A copy of the routine verification checklist with your delivery

Complying with the standard

Design Verification

Performed on representative samples and designs

Routine Verification

Performed on every supplied assembly – by checking against Design Verification

If you have any further questions:

[email protected]

www.3phasedesign.com

www.IEC61439.com

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Thank you for your time

mailto:[email protected]



http://www.3phasedesign.com/

http://www.iec61439.com/

Documents

Introducing IEC-61439-3PD