CLC/TR 50479:2007
(Main)Electrical installation guide - Selection and erection of electrical equipment - Wiring systems - Limitation of temperature rise of connecting interfaces
Electrical installation guide - Selection and erection of electrical equipment - Wiring systems - Limitation of temperature rise of connecting interfaces
This Technical Report is for use as a guide for electrical installations. It is applicable to the limitation of temperature rises of connecting interfaces.
Leitfaden für elektrische Anlagen - Auswahl und Errichtung elektrischer Betriebsmittel - Kabel- und Leitungsanlagen - Begrenzung des Temperaturanstiegs bei Schnittstellenanschlüssen
Dieser Technische Bericht dient zur Anwendung als Leitfaden für elektrische Anlagen. Er gilt für die Begrenzung des Temperaturanstiegs bei Schnittstellenanschlüssen.
Guide pour les installations électriques - Choix et mise en oeuvre des matériels électriques - Canalisations - Limitation des échauffements dus aux interfaces de connexion
Le présent Rapport Technique est utilisé comme guide pour les installations électriques. Il s’applique à la limitation des échauffements dus aux interfaces de connexion.
Vodilo za električne inštalacije - Izbira in namestitev električne opreme - Inštalacijski sistemi - Omejitev segretka na priključkih
General Information
- Status
- Published
- Publication Date
- 27-Mar-2007
- Technical Committee
- CLC/TC 64 - Electrical installations and protection against electric shock
- Drafting Committee
- IEC/TC 64 - IEC_TC_64
- Parallel Committee
- IEC/TC 64 - IEC_TC_64
- Current Stage
- 6060 - Document made available - Publishing
- Start Date
- 28-Mar-2007
- Completion Date
- 28-Mar-2007
Overview
CLC/TR 50479:2007 is a technical report published by CENELEC that serves as a practical guide for electrical installations, focusing specifically on the selection and erection of electrical equipment in wiring systems. The core purpose of this document is to provide comprehensive guidance on the limitation of temperature rise of connecting interfaces-a critical factor influencing the safety and reliability of electrical systems. Excessive temperature rise at connecting terminals can degrade insulation, lead to equipment failure, and compromise electrical safety. This report outlines strategies to prevent such thermal risks, ensuring electrical installations operate within safe temperature limits.
Key Topics
Temperature Limits of Terminals: The report defines how terminal temperatures are influenced by ambient conditions and internal heat dissipation. It highlights the importance of maintaining temperatures at connecting interfaces that do not damage cable or conductor insulation.
Methods for Limiting Temperature Rise:
- Limitation of enclosure contents: Reducing the density of circuits in conduit or trunking to prevent overheating.
- Equipment spacing: Optimizing distance between components to improve natural ventilation and heat dissipation.
- Appropriate equipment arrangement: Positioning heat-dissipating devices to avoid raising temperatures of adjacent terminals.
- Ventilation and air conditioning: Use of natural or forced ventilation in enclosures to maintain safe operating temperatures.
- Derating of equipment: Selecting components rated for higher currents to reduce overall heat generation.
- Enclosure material selection: Choosing materials that enhance thermal dissipation.
- Maintenance of conductor clamping: Ensuring secure connections to prevent increased resistance and heating.
Temperature Compatibility of Insulation: The guide stresses matching the thermal ratings of conductor insulation materials (like EPR, PVC, XLPE, silicone rubber) with expected operating temperatures. It offers permissible steady-state temperature values for common insulation types to safeguard against premature degradation.
Improvement Techniques for Conductors:
- Increasing conductor cross-sectional area.
- Using intermediate terminals to connect cables with larger cross-sections or thermal ratings.
- Employing high-temperature sleeves or replacements for conductor insulation.
- Separating conductors in multicore cables to reduce local temperature build-up.
Applications
CLC/TR 50479:2007 is essential for electrical engineers, designers, and installers engaged in:
- Designing electrical wiring systems where controlling heat at connecting interfaces is critical to prevent failures.
- Selecting electrical components and materials compatible with expected load and ambient conditions.
- Implementing installation practices that mitigate heat accumulation in enclosures, panels, and distribution boards.
- Verifying and maintaining existing installations to ensure terminal temperatures remain within safe limits and preserve insulation integrity.
- Enhancing safety in residential, commercial, and industrial buildings by following recognized temperature control guidelines.
- Integrating thermal management techniques such as spacing, ventilation, and derating for robust electrical installation performance.
Related Standards
This report complements and references key standards including:
- EN 60439-1 & EN 60439-3: Standards on low-voltage switchgear and controlgear assemblies covering temperature rise test methods.
- HD 384.5.523: Provides data on current-carrying capacities of wiring systems, correlating to temperature limits.
- CLC/TR 60890: Describes methods for temperature-rise assessment in electrical assemblies.
- IEC/TR 60943: Offers guidance on permissible temperature rises for electrical equipment parts, particularly terminals.
Compliance with CLC/TR 50479:2007 alongside these standards ensures that electrical installations respect safe thermal operation criteria, reducing risks associated with overheating at connecting interfaces.
By applying the guidelines outlined in CLC/TR 50479:2007, professionals can achieve optimized electrical wiring installations with enhanced safety, reliability, and longevity through effective management of terminal temperature rises. This contributes to the prevention of insulation failure, equipment damage, and potential electrical hazards.
Frequently Asked Questions
CLC/TR 50479:2007 is a technical report published by CLC. Its full title is "Electrical installation guide - Selection and erection of electrical equipment - Wiring systems - Limitation of temperature rise of connecting interfaces". This standard covers: This Technical Report is for use as a guide for electrical installations. It is applicable to the limitation of temperature rises of connecting interfaces.
This Technical Report is for use as a guide for electrical installations. It is applicable to the limitation of temperature rises of connecting interfaces.
CLC/TR 50479:2007 is classified under the following ICS (International Classification for Standards) categories: 13.260 - Protection against electric shock. Live working; 91.140.50 - Electricity supply systems. The ICS classification helps identify the subject area and facilitates finding related standards.
CLC/TR 50479:2007 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2007
1DGRPHãþD
SIST R064-002:2000
9RGLOR]DHOHNWULþQHLQãWDODFLMH,]ELUDLQQDPHVWLWHYHOHNWULþQHRSUHPH
,QãWDODFLMVNLVLVWHPL2PHMLWHYVHJUHWNDQDSULNOMXþNLK
Electrical installation guide - Selection and erection of electrical equipment - Wiring
systems - Limitation of temperature rise of connecting interfaces
Leitfaden für elektrische Anlagen - Auswahl und Errichtung elektrischer Betriebsmittel -
Kabel- und Leitungsanlagen - Begrenzung des Temperaturanstiegs bei
Schnittstellenanschlüssen
Guide pour les installations électriques - Choix et mise en oeuvre des matériels
électriques - Canalisations - Limitation des échauffements dus aux interfaces de
connexion
Ta slovenski standard je istoveten z: CLC/TR 50479:2007
ICS:
91.140.50 Sistemi za oskrbo z elektriko Electricity supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL REPORT
CLC/TR 50479
RAPPORT TECHNIQUE
March 2007
TECHNISCHER BERICHT
ICS 13.260; 91.140.50 Supersedes R064-002:1994
English version
Electrical installation guide -
Selection and erection of electrical equipment -
Wiring systems -
Limitation of temperature rise of connecting interfaces
Guide pour les installations électriques - Leitfaden für elektrische Anlagen -
Choix et mise en oeuvre Auswahl und Errichtung
des matériels électriques - elektrischer Betriebsmittel -
Canalisations - Kabel- und Leitungsanlagen -
Limitation des échauffements Begrenzung des Temperaturanstiegs
dus aux interfaces de connexion bei Schnittstellenanschlüssen
This Technical Report was approved by CENELEC on 2006-10-09.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. CLC/TR 50479:2007 E
Foreword
This Technical Report was prepared by SC 64B, Protection against thermal effects, of Technical Committee
CENELEC TC 64, Electrical installations and protection against electric shock.
The text of the draft was submitted to a vote and was approved by CENELEC as CLC/TR 50479 on
2006-10-09.
This Technical Report supersedes R064-002:1994.
__________
- 3 - CLC/TR 50479:2007
INTRODUCTION
When designing an installation or during initial verification, it is sometimes observed that the temperatures
reached by interfaces between terminals and conductors are higher than those which could be withstood by
insulation in normal service.
In this case, precautions shall be taken so that the temperature attained by terminals in normal service shall
not impair effectiveness of the insulation of conductors connected to them or supporting them.
See HD 384.5.52 ‘Electrical installations of buildings – Part 5: Selection and erection of electrical equipment
– Chapter 52: Wiring systems’.
52.1 General
52.1.1 Scope
This Technical Report is for use as a guide for electrical installations. It is applicable to the limitation of
temperature rises of connecting interfaces.
52.1.2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 60439-1:1999, Low-voltage switchgear and controlgear assemblies - Part 1: Type-tested and partially
type-tested assemblies (IEC 60439-1:1999)
EN 60439-3:1991, Low-voltage switchgear and controlgear assemblies - Part 3: Particular requirements for
low-voltage switchgear and controlgear assemblies intended to be installed in places where unskilled
persons have access for their use - Distribution boards (IEC 60439-3:1990, modified)
HD 384.5.523 S2:2001, Electrical installations of buildings - Part 5: Selection and erection of electrical
equipment - Section 523: Current-carrying capacities in wiring systems
(IEC 60364-5-523:1999, modified)
CLC/TR 60890:2002, A method of temperature-rise assessment by extrapolation for partially type-tested
assemblies (PTTA) of low-voltage switchgear and controlgear (IEC 60890:1987 + corr. 1988 + A1:1995)
IEC/TR 60943:1998, Guidance concerning the permissible temperature rise for parts of electrical equipment,
in particular for terminals
52.2 Maximum temperatures of terminals in normal service conditions
52.2.1 The temperature of a terminal is the sum of the ambient temperature and its temperature rise in
normal service.
Product standards give conventional limit values for temperature rise under defined test conditions, but do
not indicate, in general, limits for permissible temperature rises in service conditions.
Relevant standards in this resp
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