IEC 61439 Verification Methods 

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iec5858The (relatively new) switchgear and control gear standard, IEC 61439 'Low-voltage switchgear and controlgear assemblies' , ensures compliance to the standard by a series of design and routine verifications.

Design Verifications

The standard has three methods which can be used to verify the design characteristics of an assembly will meet the standard. These are verification by test, verification by calculation and verification by the use of design rules.

The following table (table D.1 from Annex D of the standard, IEC:2011) summarizes each characteristic and the allowable options for design verification:

  Verification options
No. Characteristics to be verified Clauses or
Testing Calculation Design
1 Strength of materials and parts:
Resistance to corrosion
Properties of insulating materials:
Thermal stability
Resistance of insulating materials to abnormal
heat and fire due to internal electric effects
Resistance to ultraviolet (UV) radiation
Mechanical impact










2 Degree of protection of the enclosures 10.3 YES NO YES
3 Clearances 10.4 YES NO NO
4 Creepage distances 10.4 YES NO NO
5 Protection against electric shock and integrity
of protective circuits:
Effective continuity between the exposed conductive
parts of the assembly and the protective circuit
Short-circuit withstand strength of the protective








6 Incorporation of switching devices and components 10.6 NO NO YES
7 Internal electrical circuits and connections 10.7 NO NO YES
8 Terminals for external conductors 10.8 NO NO YES
9 Dielectric properties:
Power-frequency withstand voltage
Impulse withstand voltage



10 Temperature-rise limits 10.10 YES YES YES
11 Short-circuit withstand strength 10.11 YES YES NO
12 Electromagnetic compatibility (EMC) 10.12 YES NO YES
13 Mechanical operation 10.13 YES NO NO


Routine Verification

Routine verification is carried out the detect faults in workmanship and the correct functioning of the panel.  The standard (IEC:2011) list the following:

  1. Construction (see 11.2 to 11.8)
    1. degree of protection of enclosures
    2. clearances and creepage distances
    3. protection against electric shock and integrity of protective circuits
    4. incorporation of built-in components
    5. internal electrical circuits and connections
    6. terminals for external conductors
    7. mechanical operation
  2. Performance (see 11.9 to 11.10)
    1. dielectric properties
    2. wiring, operational performance and function

Original and Assembly Manufacturer

IEC 61439 Verification, Courtesy ABB
The standard also tries to explain the differing roles of the original panel manufacturer and a assembly manufacturer.  The original manufacturer is the party who initially carries out the panel design and arranges for the necessary design verifications to be performed.  The assembly manufacturer is the party who finally builds the panel to the customers requirements and delivers it.    The image shows the relationship between the parties and who performs the verification.

Note: if an assembly manufacturer incorporates his own arrangements, he is then deemed to be the original manufacturer by the standard.

In addition to this post, you may also be interested in my post on 'Forms of Internal Separation' according to the standard:

Switchboard - Forms of Internal Separation

Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

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  1. CM3PhaseDesign's avatar CM3PhaseDesign says:
    2/21/2012 12:16 PM

    Hi Steven.
    I just wanted to confirm with you that the table D1 above is now out of date. With the issue of Edition 2 last year this table was amended.

    You can see the current table on our website

    • Steven's avatar Steven says:
      2/21/2012 1:28 PM

      Thanks for pointing this out. I have updated the table to the 2011 edition.

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