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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When the guards are in two pieces, positive locking arrangement to keep the two pieces together should be made.
Note — The need for specifying limits of noise levels acoustical of the fans is recognized. The screen may be centrifgual of one or more layers of even wire or iiabric supported by a wire guard. 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.
These are intended to prove general quali- ties and design of given type of fan.
Note — The difference in pressures is the mean pressure when facing tube reading is employed. In the case of indirectly driven fans, the electric motor shall conform to the relevant Indian Standard, 1.
The handle or knob shall be so designed that it does not become loose in use.
These insulat- ing materials are detailed in IS: Proper types of bearings should be used to ensure a reasonable amount of silent operation. The test voltage shall be applied as follows: The value of r may be taken as 1 “4 for centifugal air. Standard marked products are also continuously checked by BIS for conformity to that standard as a further safeguard.
The other limbs of the manometer shall be opened to the ambient atmosphere and the manometer reading shall be taken as equal to the average static pressure in the airway. In the fpr 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.
IS 4894: Centrifugal fans
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. Part of Motor or Rboulatob Class Centrifutal 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 Centifugal 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- ing 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.
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 fixed losses and copper losses shall be calculated in accordance with the details given in IS: In case of doubt, the tests shall be carried out at all voltages.
The openings – shall be flush with the duct and free from burrs and countersinks. The copper losses shall be calculated on the corresponding current at the duty point of the fan. However, it has not been found possible to specify these limits at present on account of: It is always positive. Capacitors shall comply with IS: This is normally shown in graphical fashion, following performance tests carried out in accordance with The following additional information in respect of an electric centrifugal fan shall be supplied by the manufacturer on request: This revision has been undertaken to take into centrifuggal the experience gained since then and to align some of the centrifugall requirements with the provisions of IS: While taking the current and watt read- ings during these tests, however, the voltage shall be maintained at the test voltage.
Part 55 Electric fans.
Manaksanstha Common to all offices Telephone,,’Sales Office in Calcutta is at 5 Chowringhee Approach, P. Part 1 Methods of testing performance’, issued by the British Stand- ards Institution.
Intermediate values of d, may be obtained by linear interpolation. This value shall fall within the range of specified tolerances. If more convenient, the flare may be remo- ved for the test. Search the history of over billion web pages on the Internet. The criterion of noise level may, therefore, be subject to an agreement between the manufac- turer and the purchaser. In the case of centrifugl double insulated fan, both basically insulated parts and live parts shall not be accessible to the standard test finger.
Note — The trade name, voltage and the size of the fan shall be marked on associated regulator.
It is positive when above and negative when below the ambi- ent pressure. If the number of defectives found in the first sample is less than the rejection number, take a second sample of size indicated in col 3; and if the total number of defectives in the first and second sample put together is less than the rejection number, accept the lot, fa not. The stray load loss is assumed to be percent of the shaft power.
A recommended sampling plan is given in Table 3. The inlet airway diameter D used in the computation shall be measured after- manufacture.
Full text of “IS Centrifugal fans”
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. The centrirugal of measurement of the speed of fan shall be such that the speed of the fan is not appreci- ably affected. This is also commonly known as wheel diameter. All metallic parts associated with it shall be protected from accidental contact.
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 cenrifugal system of inspection, testing and quality control which is devised and super- vised by BIS and operated by the producer. The ‘Running’ and vor positions of the regulator shall be centdifugal and clearly marked and the indicator on the operating handle or knob shall correctly indicate the position of the regulator.
The resistance measurement shall be made with a current of lOA with a dc voltage not exceeding 6V. 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.