Comments. IS Code. Recent; Popular; Featured. IS – – Pallets for materials. Buy BIS IS (R) SPECIFICATION FOR CENTRIFUGAL FANS from SAI Global. Standard Air. Centrifugal fans for use in mines and hazardous atmospheres may requirt: additional requirements to be met, not covered by this standard.
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Part of Motor or Rboulatob Class A Class E Tbmpbbatukh-Risb, “C Method OF Mbasu- BBMBNT 6 Change of resi- stance Fog of resi- stance Insula- tion 3 60 60 Insula- tion 4 75 75 Class B Insula- tion 5 80 80 The temperature-rise shall not reach such a value that there is a risk of injury to any insulating material on adjacent parts of the regulator 40 40 40 Thermo- meter Thermo- meter 1 2 i] Insulated win- afn of motors ii Insulated wrin- dings, if any, of regulator with conti- nuous runn- ing on cenyrifugal contact iii Regulator resi- stance unit with conti- nuous runn- ing on any contact iv External surfa- ces likely to be touched during normal usage Note 1 — The thermocouples, if used, should be applied only to external surfaces which may be reached by an ordinary thermometer.
This revision has been undertaken to take into account the experience gained since then and to align i of the safety requirements with the provisions of IS: Part 1 Methods of testing performance’, issued by the British Stand- ards Institution.
Manaksanstha Common to all offices Telephone,,’Sales Office in Calcutta is at 5 Chowringhee Approach, P.
Intermediate values of d, may be obtained by linear interpolation. In the case of a double insulated fan, both basically insulated parts and live parts shall not be accessible to the cenrrifugal test finger.
Note — In this specification, the term ‘fan’ shall be used to mean centrifugal fan as supplied, without any addition to the inlet or outlet, except where such addition is specified.
Such an addition shall then be regar- ded as a part of the fan. The guards shall be securely attached and shall be adequately rigid to resist accidental contact with the blades.
Full text of “IS Centrifugal fans”
Note — The need for specifying limits of noise levels acoustical of the fans is recognized. The Standard Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well-defined system of inspection, testing and quality control which is devised and super- vised by BIS and operated by the producer.
Standard marked products are also continuously checked by BIS for conformity to that standard as a further safeguard. The most probable operating point for the fan shall be at the intersection of the fan characteri- stic and the system resistance line. This is also commonly known as wheel diameter. A recommended sampling plan is given in Table 3. The difference between the inlet volume flow at the intersection and the specified inlet volume flow that is, the duty point shall be recorded as the measure of departure of the fan from the specified perfor- mance.
Full text of ” IS In the case of fans for use on three-phase, two separate earthing terminals shall be provided. The method of measurement of the speed of fan shall be such that the speed of the fan is not appreci- ably affected.
When the air flow, in cubic metres per hour, is numeri- cally less than 16 times the airway diameter in metres, then the coefficient ventrifugal discharge shall be taken appropriate to the Reynolds number given in Table 2. The stray load loss 484 assumed to be percent of the shaft power. For Reynolds numbers of and above, the coeffi- cient of discharge is 0″ and centrifugsl cover the majority of fan tests. As type test, this test should preferably be done immediately after the temperature-rise test.
Note — Nevertheless, fans made for other freque- ncies shall be considered to comply with the specifica- tion provided they do so in all other relevant respects. In the case of inductance type regulator, it is essential that no portion of the inductive winding should remain permanently short-circuited in any of the running positions.
Details of conditions under which a licence for the use of the Standard Mark iw be granted to manufacturers or producersmay be obtained from the Bureau of Indian Standards. Note — The trade name, voltage and the size of the fan shall be marked on associated regulator.
These are intended to prove general quali- ties and design of given type of fan.
This test shall be carried out with the guard if any, in position. This requirement is applicable for all positions in the normal use. It is positive when above ls negative when below the ambi- ent pressure. However, it has not been found possible to specify these limits at present on account of: The test voltage shall be applied as follows: Centrifugal fans [ETD 5: The criterion of noise level may, therefore, be subject to an agreement between the manufac- turer and the fah.
It is always positive. In case of doubt, the tests shall be carried out at all voltages. Part 1 General requirements second revision. Search the history of over billion web iss on the Internet. A system resistance line shall also be drawn, passing through the specified duty point such that the total or static pressure varies with the square of the inlet volume flow see Fig.
The ‘Running’ and ‘OFF’ positions of the regulator shall be distinctly and clearly marked and the indicator on the operating handle or knob shall correctly indicate the position of the regulator. This is normally shown in graphical fashion, following performance tests carried out in accordance with This value shall fall within the range of specified tolerances. All metallic parts associated with it shall be protected from accidental contact.
The amendments issued to the previous edition of the standard have also been incorporated in this revision. When the guards are in two pieces, positive locking arrangement to keep the two pieces together should be made. The value to be adopted for the temperature of the cooling air during a test shall be the mean of the readings of the thermometers taken at equal intervals of time during the last quarter of the duration of the test.
These insulat- ing materials are detailed in IS: Never- theless, fans made to work in higher cooling air tem- peratures may be regarded as complying with this specification provided the temperature-rise values are reduced corresponding to the increase in cooling air temperature.
IS 4894: Centrifugal fans
The inlet airway diameter D cfntrifugal in the computation shall be measured after- manufacture. Note — The difference in pressures is the mean pressure when facing tube reading is employed. The screen may be composed of one or more layers of even wire or iiabric supported by a wire guard. A fan with protective electrical insulation may be of all-insulated construction or have either double insulation or reinforced insulation.
However, if regulators are i, this shall be a matter of agreement between the purchaser and the supplier. The following additional information in respect of an electric centrifugal fan shall be supplied by the manufacturer on request: The other limbs of the manometer shall be opened to the ambient atmosphere and the manometer reading shall be taken centrifgal equal to the average static pressure in the airway.
Part 55 Electric fans.