TR 62001 @ IEC:2009(E) -143- personnel safety standards. The customer may specify what method should be adopted and he should specify the minimum safety clearance. It is recommended that the customer requires the contractor to specify the type of support insulators used for the mounting of the filter components and the capacitor bushings. Usually the insulators and bushings are of porcelain type. Sufficient creepage and clearance must be provided for reliableoperation of the equipment.Based on information available to the prescribe the minimum creepage distance of the insulators. Typical values for specific creepage are between 25 mm/kv to 45 mm/kV depending on the site pollution level. (See IEC 60815 series, as well as 17.4.2 of this document). Creepage requirements should be based on the maximum voltage (including harmonics) appearing across the insulators or bushings, evaluated in accordance with 10.2.4 and 10.2.5 of this document. interchangeable components so as to simplify maintenance and stocking of spares. ENSE For ease of transportation and installation, the customer may require that each equipment EDTC component should be equipped with lifting eyes or similar provision for lifting the unit. The customer may impose a maximum height requirement for any equipment. He may further require a maximum limit on weight of components (capacitor units for example) depending on their location relative to other filter equipment. If the contractor exceeds those limits, he should T1 provide appropriate tools for handling during installation and maintenance. The outline of the filter components should be designed so as to eliminate as far as possible TIC any visible corona at voltage levels typically up to 2o % above rated voltage. The customer may advise the bidder that the filter components shall be designed to withstand the operational mechanical forces without damage or reduction of life. These are vibrational forces during normal operation, electromagnetic forces during external faults, wind forces, ice loading and seismic forces, if applicable. In case of breakage of one support insulator, the construction must remain stable. The customer may require a static calculation of the filter structures. certain filter components such as capacitors, current transformers, etc. on condition that the specified maintenance is provided. 18.1.3.2 Quality system and documentation requirements It is recommended that the customer specifies his minimum requirements on the contractor's quality system to be applied by the contractor to the design, production, testing, installation and maintenance of the a.c. filter equipment. Usually, the quality program is documented by the contractor's quality manual. The customer should review the contractor's manual and he should reserve the right for auditing the quality system as described by the manual. As a general guideline the application of Iso 9200 [36] or other internationally recognized quality program standards of comparable level should be adequate for the supply of the a.c. filters equipment. Further to the standard quality program, the customer may state specific requirements on the kind andqualityof materialsandworkmanship.These shouldincludeforexamplerequirements on materials used for terminals and electrical wiring, surface protection by galvanizing or painting, specific requirements on welding, etc. TR 62001 @ IEC:2009(E) - 144 - The customer may specify requirements on the contractor's documentation. Usually the activities for design and production inspection, testing, installation and commissioning are basedoninspectionand testplans.Theinspectionandtestplanshoulddefineholdpointsfor witnessing inspection or testing by the customer or by an organization representing the customer. It is recommended that customer requests the contractor to submit this documentation for approval during the detailed design stage of the equipment. 18.1.3.3 Test requirements For general requirements, it is recommen