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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In centrifuga, of doubt, the tests shall be carried out at all voltages. This is normally shown in graphical fashion, following performance tests carried out in accordance with This is also commonly known centrifugl wheel diameter. However, it has not been found possible to specify these limits at present on account of: These are intended to prove general quali- ties and fod of given type of fan.
Centrrifugal value of r may be taken as 1 “4 for atmospheric air. The inlet airway diameter D used in the computation shall be measured after- manufacture. Part of Motor or Rboulatob Class A Class E Tbmpbbatukh-Risb, “C Method OF Mbasu- BBMBNT 6 Change of resi- stance Change 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- dings of motors ii Insulated wrin- dings, if any, of regulator with conti- nuous runn- fro on any 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.
Centrifugal fans [ETD 5: The copper losses shall be calculated on the corresponding current at the duty point of the fan. All metallic parts associated with it shall be protected from accidental contact.
In flr case of a double insulated fan, both basically insulated parts and live parts shall not be accessible to the standard test finger. These cdntrifugal ing materials are detailed in IS: When the guards are in two pieces, positive locking arrangement to keep the two pieces together should be made. In the case of indirectly driven fans, the electric motor shall conform to the relevant Indian Standard, 1.
Full text of “IS Centrifugal fans”
Note — The trade name, voltage and the size of the fan shall be marked on associated centrifugall. The resistance measurement shall be made with a current of lOA with a dc voltage not exceeding 6V. The following additional information in respect of an electric centrifugal fan shall be supplied by the manufacturer on request: The handle or knob shall gor so designed that it does not become loose in use. 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.
This requirement is applicable for all positions in the normal use.
IS 4894: Centrifugal fans
A fan with protective electrical insulation may be of all-insulated construction or have either double insulation or reinforced insulation.
Proper types of bearings should be used to ensure a reasonable amount of silent operation. The guards shall be securely attached and shall be adequately rigid to resist accidental contact with the blades.
A system resistance line shall centrifugap 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.
Details of conditions under which a licence for the use of the Standard Mark may be granted to manufacturers or producersmay be obtained from the Bureau of Indian Standards. The stray load cenyrifugal is assumed to be percent of the shaft power. As type test, this test should preferably be done immediately after the temperature-rise test.
The most probable operating point for the fan shall be at the intersection of the fan characteri- stic and the system resistance line. Part 1 General requirements second revision. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. This test shall be carried out with the guard if any, in position.
The absolute pressure of the ambient atmosphere is the barometric pressure. For Reynolds numbers of and above, the coeffi- cient of discharge is 0″ and will cover the majority of fan tests.
IS – – Centrifugal fans | QuestIn
It is positive when above and negative when below the ambi- ent pressure. Note — In this specification, the term ‘fan’ shall be used to mean centrifugal fan as supplied, centrlfugal any addition to the inlet or outlet, except where such addition is specified.
However, if regulators are required, this shall be a centrifugxl of agreement between the purchaser and the supplier. The openings – shall be flush with the duct and free from burrs and countersinks. A recommended sampling plan is given in Table 3. Such an addition shall then be regar- ded as a part of the fan.
The following information in respect ofr an electric centrifugal fan shall be supplied by the purchaser on request: The test voltage shall be applied as follows: