IEC 61439-1: 2011 Low-voltage switchgear and controlgear assemblies – Part 1: General rules

The IEC 61439-1 standard, titled “Low-voltage switchgear and controlgear assemblies – Part 1: General rules”, specifies the general requirements for low-voltage switchgear and controlgear assemblies. It applies to assemblies with rated voltages up to 1000V AC or 1500V DC and is intended to ensure the safety, reliability, and performance of such assemblies. Below is a summary of the key content of this standard:

Scope and Application
• IEC 61439-1 provides the general rules and definitions that apply to low-voltage switchgear and controlgear assemblies, including assemblies used in industrial, commercial, and other installations.
• It serves as a foundation for more specific parts of the IEC 61439 series that address particular types of assemblies, such as power switchgear and controlgear, distribution boards, and assemblies for construction sites.

Definitions and Terminology
• The standard defines essential terms like “assembly”, “functional unit”, “enclosure”, “protective circuit”, and other technical terms relevant to low-voltage switchgear and controlgear assemblies.

Design Verification
• Design verification is mandatory to ensure compliance with the standard’s requirements. It can be achieved through:
• Testing: Physical tests on a sample of the assembly.
• Calculation: Mathematical or empirical methods to demonstrate conformity.
• Comparison to a reference design: Using existing designs that are already verified.
• The key tests include temperature-rise limits, dielectric properties, short-circuit withstand strength, clearance and creepage distances, and mechanical operation.

Construction Requirements
• Assemblies must be designed and constructed to withstand mechanical, electrical, and thermal stresses under normal operating conditions.
• Key elements include proper protection against electric shock, insulation coordination, and protection against mechanical impacts.
• Clearances and creepage distances must be maintained to ensure safety and prevent electrical failure.

Electrical Characteristics
• The standard defines the electrical ratings of the assembly, including:
•  Rated current (In): Maximum current the assembly can handle.
•  Rated insulation voltage (Ui): The voltage at which the assembly is designed to operate.
•  Rated impulse withstand voltage (Uimp): The assembly’s ability to withstand transient overvoltages like lightning strikes.
•  Short-circuit withstand capacity: The ability of the assembly to withstand high current surges without failure.

Protection and Safety Measures
• Protection against electric shock: The assembly must be designed to ensure operator safety and prevent contact with live parts.
• Overcurrent protection: Devices such as circuit breakers must be included to protect against overloads and short circuits.
• Environmental protection: Enclosures should have adequate IP (Ingress Protection) ratings for dust and water resistance.

Operating Conditions
• The standard defines the environmental conditions under which the assemblies should be able to operate, including temperature ranges, humidity, altitude, and vibration.
• Assemblies must be tested for temperature rise, mechanical endurance, and resistance to corrosion to ensure long-term reliability.

Mechanical and Structural Requirements
• The assembly must be constructed to provide mechanical strength and stability, ensuring it can withstand stresses during installation and operation.
• Proper labeling, terminal markings, and wiring arrangements must be provided to ensure clarity and safety in operation and maintenance.

Verification Tests
• Specific tests are required to verify that the assembly meets performance and safety criteria, including:
•  Temperature-rise test: Ensures components operate within safe temperature limits under load.
•  Dielectric tests: Verifies the insulation of the assembly under high voltage conditions.
•  Short-circuit tests: Confirms the assembly can safely handle short-circuit conditions.
•  Mechanical operation test: Tests durability under repeated operation.
• Ingress protection (IP) tests: Assesses resistance to dust and water.

Documentation and Information
• The manufacturer must provide comprehensive documentation, including technical specifications, installation instructions, circuit diagrams, and maintenance guidelines.
• Clear product labeling, including electrical ratings, must be present for safe installation and operation.
11. Routine Verification
• In addition to design verification, routine verification must be conducted on each assembly produced to confirm compliance with critical safety parameters. This includes testing for dielectric strength, wiring integrity, and function of protective measures.

Conclusion
IEC 61439-1 outlines the fundamental principles for the design, construction, and verification of low-voltage switchgear and controlgear assemblies, with a strong emphasis on safety, reliability, and performance under a range of environmental and operational conditions. It provides a framework to ensure that such assemblies are robust, safe for use, and capable of performing reliably in various industrial and commercial applications.

LISUN supplies the fully test solutions for the following IEC 61439-1: 2011 , please see the below excel table:

IEC 61439-1 Clause and Subject	LISUN Model
3.6.15 &3.6.16 Comparative tracking index	TTC-1
3.6.17 Disruptive discharge	WB2681A
3.7 Protection against electric shock	LS9955
3.8.9.3 Insulation Voltage	WB2681A
3.8.9.4 Impluse withstand voltage	WB2671
8.1.2 (10.2.2)Protection against corrsion	YWX/Q-010
8.1.3.2.3 Resistance of insulating material to abnormal heat and fire due to internal electric effect	ZRS-3H and ZY-3
8.1.4(10.2.4) Resistance to ultra-violet radiation	UV-263LS
8.2.1(10.2.6) Protection aganst mechanical impact	IK07-10
8.2.2(10.2.6) protection against contact with live parts, ingress of solid foreign bodies and water	JL-12 and JL-34
8.3.3 Creepage disctance	CK-1
10.2.2.2 Thermal Chamber	GDJS-015B
10.3 Degress of protection of IP test	JL-12 and JL-34 and JL-56 and SC-015
10.5 Protection against electric shock	LVD-100KG
10.9.3 Impluse withstand voltage	SUG255
10.10(9.2) Verfication of temperature rise	WS-1
J.9.4.3 Immunity	RFCI61000-6
J.9.4.4 Emission	EMI-9KB
J.10.12.1(Table 1 and Table 2)	ESD61000-2
	GTEM-2
	EFT61000-4
	SG610000-5
	RFCI61000-6
	PFM61000-8A
	CSS61000-11