Requirements for access technology of tower crane

2022-08-02
  • Detail

Relevant requirements for tower crane access technology in the EU market

any specified product, whether produced outside the EU or in EU Member States, must meet the requirements of EU directives and relevant coordinated standards before being put on the EU market, and CE mark, i.e. CE certification, must be applied

(1) specific EU directives

according to the relevant classification definitions of the EU new method directive, the CE certification of tower crane must meet the requirements of the following three directives: Machinery Directive (2006/42/ec), Noise Directive (2000/14/ec+2005/88/ec) and Electromagnetic Compatibility Directive (2004/104/ec)

among them, the products listed in Annex IV of the machinery directive belong to dangerous machinery. The tower crane is within this range. For dangerous machinery, the CE mark can be posted on the product only after the product has passed the ectypeexamination by the notifiedbody announced by the European Union

in addition, the mechanical equipment listed in Article 12 of the Noise Directive has set the noise limit and must be reviewed by the EU notified body according to the conformity assessment procedure. The tower crane is in the list of mechanical equipment listed in Article 12

tower crane is not listed in the product catalogue for which EMC certification must be enforced. Therefore, the EU CE certification of tower crane products is mainly based on the machinery directive and Noise Directive. Enterprises can meet the requirements of relevant coordination standards through electrical systems and components, and adopt the self declaration method for EMC certification

(2) main coordination standards

the harmonized standards published in the official journal of the European community are closely related to specific regulations. Each harmonized standard must match the basic requirements of relevant directives. That is, the products produced by the enterprise according to the coordinated standards should be assumed to meet the basic requirements of the directive

EU harmonized standards are divided into three categories: class a basic standards, class B group standards and class C product standards. For specific product certification, if there is a class C harmonized standard, the class C standard shall be taken as the main technical basis; If there is no class C standard, it shall be based on class B and class a coordinated standards related to the product

the newly released class C coordination standard for tower crane is: en14439:2006+a2:2009, crane safety tower crane. The class a standards on which the certification is based include: eniso:2003, basic concepts and general principles of mechanical safety design part 1: basic terms and methods; Eniso:2003, basic concepts and general principles of mechanical safety design part 2: technical principles, and eniso:2007, mechanical safety risk assessment Part 1: principles. Class B coordination standards mainly include: en/iec:2008, mechanical safety, mechanical electrical equipment Part 32: requirements for cranes; En+a1:2008, safety, health and safety requirements for cranes - Part 2: limiting and indicating devices; Eniso13850:2008, design principles for mechanical safety emergency stop; En13586+a1:2008, crane access; En953:1997+a1:2009, general requirements for the design and construction of fixed and mobile protective devices for mechanical safety; En:2006+a safety of machinery - Ergonomic design principles - Part 1: Terminology and general principles if manufactured and used in accordance with the standard 1:2009; Eniso3744:2009, acoustic sound pressure method for determination of sound power level of noise source, engineering method in an approximate free field above a reflecting surface, etc

(3) analysis of technical points

one of the key points of EU certification is to review the establishment and preparation of technical documents (TCF). Among them, the necessary document for review: risk assessment report is particularly critical for tower crane products. For all potential hazard sources, dangerous states, uncertain impacts and other risk elements of the tower crane, systematic methods must be adopted to predict, judge and evaluate, determine the risk level, and take safety measures to eliminate or reduce the risk (including three levels of intrinsic safety design, protective facilities and use of warning information) in accordance with ENISO, Define the scope of restricted use (i.e. reasonably foreseeable abnormal use shall also be considered in the design to avoid hazards caused by reasonably foreseeable abnormal use), give the results of risk assessment and form a completed risk assessment report

in addition to the technical performance of the tower crane meeting the standards, the key points of its certification mainly include: whether the design of channels, ladders, walkways, handrails and handrails can meet the safety of use and maintenance operations; Whether the settings of operating devices, display instruments, lighting, etc. comply with ergonomics to ensure that operators can clearly operate and see the lifted objects; Whether the electrical control system has safety redundancy design, such as ensuring the braking safety of hoisting mechanism and luffing mechanism in case of sudden power loss in case of power supply failure, and providing customized integrated material solutions for the lifted objects without danger - its excellent lightweight, easy to shape characteristics and durability, such as sliding or accidental falling; As well as requiring that key electrical components such as PLC, frequency converter and circuit breaker have CE certificates, the electrical grounding wire must be yellow and green wire, and the grounding symbol shall be marked on the grounding terminal, so as to ensure the grounding continuity between the standard sections of the tower body; At the same time, it is also required to ensure that the maintenance and operation personnel are equipped with fall protection ropes when walking on the boom. In terms of use information, it is required that the sound power guarantee value of the tower crane shall be given, the lifting performance curve chart shall be posted in the cab, the weight, center of gravity and lifting point of each component shall be marked on the component, whether the warning information and operation information of the remaining hazards are sufficient, clear and lasting, and the contact information in the EU must be indicated on the declaration of conformity

in the test items of tower crane certification, it should be pointed out that during the static load test, in addition to the 1.25 times static overload lifting test, the certification authority or according to the FEM standard will require the 1.33 or 1.4 times static overload stability test

for the noise test of tower crane, it is pointed out in section 5.5: noise reduction in Chapter 5: Safety requirements and/or protective measures of class C coordination standard en14439:2006+a2:2009 that the noise source of tower crane is lifting mechanism; In Appendix E, the noise test method is given, that is, the test conditions are as follows: testing the maximum electrolyte additive and diaphragm coating under no-load respectively is an important measure to cooperate with the lithium-ion battery to increase the voltage (increase the energy density), maintain the service life and ensure the safety. The hook speed is lifted and lowered, and the maximum hook speed load is lifted and lowered at the maximum hook speed with the minimum working range. The test points are: determine the radius of the hemispherical body according to the length and size of the lifting mechanism, and determine the coordinates of the microphones at the six measuring points on the surface of the new generation of experimental machine developed according to the dry powder mortar tensile test standard. Test method: each measuring point shall be measured at least three times under the no-load/loaded rising/falling conditions until the difference of three consecutive measured values does not exceed 1 dB; The maximum value of sound pressure calculated in the four test conditions shall be taken as the guarantee value. After testing 5 sets, take the average value and add the correction coefficient to obtain the final guarantee value. The noise test conditions in the cab are the same as above, and the air conditioner in the cab is required to run at the maximum speed and the windows are closed. The measurement shall be carried out according to eniso11201:1995

in the Noise Directive (2000/14/ec+2005/88/ec), it is stipulated that the limit of the guaranteed value of the tower crane sound power level is 96+lgpdb (P is the power of the lifting mechanism)

Copyright © 2011 JIN SHI