IEC 60364-4-42:2001 pdf download
IEC 60364-4-42:2001 pdf download.Electrical installations of buildings – Part 4-42: Protection for safety – Protection against thermal effects.
421.5 (422.5) Wherever electrical equipment in a single location contains flammable liquid in significant quantity, precautions shall be taken to prevent burning liquid and tt’ie products of combus lion of the liquid (flame, smoke, toxic gases) spreading to other parts of the building.
NOTE 1 Examples of such pr.caulions are
– a drainage p11 to collect leakages of liquid and ensure their eiciinchon in Iti. event of tire. or
– installation at the equipment vi a chamber at adequate lire resistance and the provision 01 sills or other means of preventing burning liquid spreading to OIlier pans 01 the building, such a chamber being ventilated solely to lie .icternal atmosphere
NOTE 2 Th generally accepted lowsr limit for a snificant quantity 11251.
NOTE 3 For less than 25 I, an arrangement to prevent th escape of liquid will wIf ice
NOTE 4 Ills desirable to switch o41 supply at ti. onset of a fire.
421.6 (422.6) The materials of enclosures arranged around electrical equipment during erection shall withstand the highest temperature likely to be produced by the electrical equipment.
Combustible materials are not suitable for the construction of these enclosures unless preventive measures against ignition are taken, such as covering with non-combustible or not readily combustible material of low thermal conductivity.
422 (482) Measures for protection against lire
422.1 (482.0) General
The requirements of this clause shall be observed in addition to tho5e of clause 421 br installations in locations where the conditions of external influences described in 422.2 exist. 422.2 (482.1) Conditions of evacuatIon In an emergency
Condition BD2: Low density occupation, difficult conditions of evacuation
BD3: High density occupation, easy conditions of evacuation
BD4: High density occupation, difficult conditions of evacuation
(according to table 51A of IEC 60364-5-5 1).
NOTE Authorities responsible tar building construction, public gatherings, lire prevention. etc. may specily which BO condition Is applicable.
422.2.1 (482.1.1) In conditions BD2, BD3 and BD4, wiring Systems shall not encroach on escape routes unless the wiring is provided with sheaths or enclosures which, either during the time authorized by regulations for building elements of the escape route or for 2 Ii in the absence of such a regulation,
• will not contribute to, or propagate a fire, and
• will not attain a temperature high enough to ignite adjacent material.
NOTE Tests on cables under tire conditions are given in IEC 60332-I, 1EC 60332-3-ID. IEC 60332-3-21, lEG 60332322, lEG 603323.23. IEC 60332324 and lEG 50332325. Tists on conduit under tirv conditions are given in IEC 60614.
Wiring systems encroaching on escape routes shall not be within arm’s reach unless they are provided with protection against mechanical damage likely to occur during an evacualion. Any wlrtng systems In escape routes shall be as short as practicable.
422.2.2 (482.1.2) In conditions BD3 and BD4, switchgear and controlgear devices, except certain devices to facilitate evacuation, shall be accessible only to authorized persons. If they are placed in passages, they shall be enclosed in cabinets or boxes constructed of non- combustible or not readily combustible material.
NOTE Detiniteons tor noncombustible and nol readily combusteble are under consideration
422.2.3 (482.1.3) In conditions BD3 and 8D4 and in escape routes, the use of electrical equipment containing flammable liquids is prohibited.
NOTE Individual auslhary capacitors Incorpofated In apparatus are not subeci to thIs requ,remenl. This escepilon principally concerns discharge lamps and capacitors 01 motoc starters.
422.3 (482.2) Nature of processed or stored materials
Condition BE2: Fire risk (according to tabffi 51A of IEC 60364.5.51).
NOTE 1 OuantiI,e ot flammable materials. surlace or volume, ol the locations may be regulated by national authorIties
NOTE 2 For explosion risks, see IEC 60079-14.
422.3.1 (482.2.1) Electrical equipment shall be restricted to that necessary to the use of these locations, except wiring systems according to 422.3.6
422.3.2 (482.2.2) Where ii is expected that dust sufficient to cause a lire hazard could accumulate on enclosures 01 electrical equipment. measures shall be taken to prevent the enclosures from attaining excessive temperatures.
422.3.3 (482.2.3) Electrical equipment shalt be so selected and erected that its normal temperature rise and foreseeable temperature rise during a fault cannot cause a lire.
These arrangements may be effected by the construction of equipment or its conditions of installation.
Special measures are not necessary where the temperature of surfaces is unlikely to cause combustion of nearby substances.
422.3.4 (482.2.4) Switchgear for protection, control and isolation shall be placed outside locations presenting BE2 conditions, unless it is in an enclosure providing a degree of protection appropriate for such a location but at least IP4X.
