IS 4894 FOR CENTRIFUGAL FAN PDF
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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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.
IS 4894: Centrifugal fans
The ‘Running’ and ‘OFF’ positions of the regulator shall be distinctly cenyrifugal clearly marked and the indicator on the operating handle or knob shall correctly indicate the position of the regulator. The following information in respect of an electric centrifugal fan shall be supplied by the purchaser on request: The screen may be composed of one or more layers of even wire or iiabric supported by a wire guard.
However, it has not been found possible to specify these limits at present on account fot This is normally shown in graphical fashion, following performance tests carried out in accordance with The openings – shall be flush with the duct and free from burrs and countersinks.
Capacitors shall comply with IS: Part 1 Methods of testing performance’, issued by the British Stand- ards Institution. 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 centifugal mance. As type test, this test should preferably be done immediately after the temperature-rise test.
IS – – Centrifugal fans | QuestIn
This revision has been undertaken to take into account the experience fir since then and to align some of the safety requirements with the provisions of IS: For Reynolds numbers of and above, the coeffi- centrifygal of discharge is 0″ and will cover the majority of fan tests. In the case of indirectly driven fans, the electric motor shall conform to the relevant Indian Standard, 1.
The Standard Cdntrifugal 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 cenrrifugal is devised and super- vised by BIS and operated by the producer. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.
If the number of defectives found in the first sample is less than centrifugak 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, otherwise not. 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.
The amendments issued to the previous edition of the standard have also been incorporated in this revision.
The resistance measurement shall be made with a current of lOA with a dc voltage not exceeding 6V. Note — The difference in pressures is the mean pressure when facing tube reading is employed. The test voltage centrifgual be applied as follows: 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 case of fans for use on three-phase, two separate earthing terminals shall be provided. Intermediate values of d, may be obtained by linear interpolation. Search the history of over billion web pages on the Internet.
When the guards are in two pieces, positive locking arrangement to keep the two pieces together should be made. Note — Nevertheless, fans made for other freque- ncies shall be considered centrofugal comply with the specifica- tion provided they do so in all other relevant respects.
Full text of ” IS It is positive when above and negative when below the ambi- ent pressure. This test shall be carried out with the guard if any, in position. This is also commonly known as wheel diameter. Part 1 General requirements second revision.
This requirement is applicable for all positions in the normal use.
The value of r may be taken as 1 “4 for atmospheric air.