An example is iec 606641 insulation coordination for equipment within lowvoltage systems. All 2 references given clearances below are to iec 606641. Deterioration is caused by slow chemical reactions. Pollution degree is a classification according to the amount of dry pollution and condensation present in the environment.
Clearances and creepage distances in lv electrical switchboards. Safety standards bodies such as underwriters laboratories ul and iec 1 categorize them as follows. Pollution degree the expected pollution around the equipment e. It is designed for use in an environment classified as pollution degree 2 in accordance with iec 606641. The international electrotechnical commission iec 6180051 is a safety standard for adjustablespeed electrical. Pollution degree 1 no pollution or only dry, nonconductive pollution occurs. No pollution or only dry, nonconductive pollution occurs.
Iec 606641 define both the isolation parameters and methodologies used to test them. It is applicable for the dimensioning of clearances, creepage distances and solid insulation stressed by any type of periodic voltages with a fundamental frequency above 30 khz and up to 10 mhz. Basis of the creepage distance is the rated voltage derived from the operating and or system voltage. A diagram for dimensioning of clearances and creepage distances for lowvoltage equipment up to 2000 m is shown in figure 1. It applies to equipment for use up to 2 000 m above sea level having a rated voltage up to a. Rating of clearance and creepage distances weco group. Insulation coordination for equipment within lowvoltage systems.
Clearances are dimensioned to withstand the required impulse withstand voltage either. This classification is important since it affects creepage and clearance distances required to ensure the safety of a product. Clearances and creepage distances in lv electrical. Creepage distances are measured by the operating voltage, the characteristic of the insulants cti value, the expected contamination level as well as the preventive measures against contamination. The tests follow much more closely the different requirements for type 1 and type 2 protection. Pollution degree of environment conditions as per iec 609471 and iec 606641. The pollution degree rating of power meters and splitcore current sensors. The international electrotechnical commission iec is the leading global organization that prepares and publishes international standards for all electrical, electronic and related technologies. What are pollution degree of environment conditions. Suitable for indoor studio camera links considering specific conditions acc. There was no correlation between data of corrosive gases to the chemical analysis of the pollution deposition on the test specimens.
Use of coating, potting or moulding for protection against pollution iec tcsc 109 on. Iec 606641 insulation coordination for equipment within lowvoltage systems. Information and technical guidance for applications above. No pollution or only dry, nonconductive pollution occurs, and pollution has no signi. Pollution degree is a classification according to the amount of dry pollution and. For tdklambdas zms100 series of acdc power supplies, pollution degree 2 was chosen and because of the products 5,000m altitude specification, those spacings were multiplied by 1. Contactors associated with overload andor short circuit protective devices. En 61984 requires that the clearance be dimensioned according to iec. Iec 606645 insulation coordination for equipment within. The pollution degree defines the level of dust and water pollution within a products. Conventional number based on the amount of conductive or hygroscopic dust, ionized gas or salt and on the relative humidity and its frequency of occurrence, resulting in hygroscopic absorption or condensation of moisture leading to reduction in dielectric strength andor surface resistivity. The equipment shall only be used in an area of not more than pollution degree 2, as defined in iec 606641.
Together, the pollution degree classification and the highest working voltage in which the system will be. Iec 606641, insulation coordination for equipment within. Pollution degree represents the amount of dust, moisture. Cti of the material and the degree of pollution in the environment. Pollution degree rating for electrical equipment national. Iec 606641 disregarded the effect of corrosive gases in its requirements. Operating voltage, pollution degree, altitude, overvoltage category and. Its a classification that relates to the quantity of condensation and dry pollution that exists in the environment.
Download standards through your account documents are normally available within a few minutes once registered, documents can be ordered and downloaded 24 hours a day excluding periods of technical maintenance. For more information, contact your local thermo fisher scientific representative. The pollution degree is from 1 to 4 in the standard, and for a panel or switchboard installed in an industrial area the pollution degree is defined as 3. Product safety considerations for insulation coordination of lowvoltage equipment scott aldous. For example, suppose the nominal voltage ui is v and the overvoltage category is iii. Contact resistance din en 605122, test 2a iec 605122 test 2a. Product safety considerations for insulation coordination. Further information about pollu tion degrees see page 940. The equipment shall be installed in an enclosure that provides a degree of protection not less than ip 54 in accordance with iec 6007915. Then the rated impulse voltage uimp is 8000 v, as per table f. Once again this standard does not specifically mention isolation.
A guide for technical committees specifying dimensioning requirements for products in accordance with iec 606641. Note 4 this standard is not applicable for microenvironmental conditions worse than pollution degree 3 or humidity level 3. If connectors being defined for pollution degree 1 and overvoltage categorie 1 are. Iec 606641, insulation coordination for equipment within lowvoltage systems part 1. The equipment may use electricity, gas, oil, solid fuel, solar thermal energy, etc. Accommodates standard lc connectors on the rear for simple installation. The manufacturer will advise upon submittal what pollution degree they want the product evaluated to. A test method is specified for allocating unclassified insulating material to the relevant water adsorption group. Pollution degree 3 is a harsher environment typical in many industrial manufacturing areas. This second edition takes into account not only iec 606641 but also the other parts iec 606643, iec 606644, and iec 606645 and their interrelation. This second edition cancels and replaces the first edition published in. A higher level of pollution will require higher creepage. Only nonconductive pollution occurs except that occasionally a temporary.
Iec 60050 international electrotechnical vocabulary. This part of iec 60664 can only be used together with iec 606641 or with iec 606645. The main changes with respect to the previous edition are listed below. Keep up to date with new publication releases and announcements with our free iec just published email newsletter. Iec606643 insulation coordination for equipment within.
With this impulse voltage 8,000 v, and a pollution degree 3 an industry environment, the minimum clearance should be 8. The pollution degree rating of power meters and splitcore. Iec606644 insulation coordination for equipment within. In my opinion pollution degree is somewhat of a misnomer. Assuming pollution degree 2 and material group iiib, the required creepage distance for basic. Small clearances can be bridged completely by solid particles, dust and water and therefore minimum clearances are specified, where pollution may be present in the microenvironment.
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