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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IS 4894: Centrifugal fans
The resistance measurement shall be made with a current of lOA with a dc voltage not exceeding 6V. When the guards are in two pieces, positive locking arrangement to keep the two pieces together should be made. Manaksanstha Common to all offices Telephone,,’Sales Office in Calcutta is at 5 Chowringhee Approach, P.
For routine and acceptance tests, instruments of class index 2 may be centrifuga. Part 55 Electric 44894.
The method of measurement of the speed of fan shall be such that the speed of the fan is not appreci- ably affected. The copper losses shall be calculated on the corresponding current at the duty point of the fan. 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.
Centrifugal fans [ETD 5: This is normally shown in graphical fashion, following performance tests carried out in accordance with Iw number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.
IS – – Centrifugal fans | QuestIn
The screen may be composed of one or more layers of even wire or iiabric supported by a wire guard. When the air flow, in cubic metres per hour, is numeri- cally less than 16 times the airway diameter in metres, then the coefficient of discharge shall be taken appropriate to the Reynolds number given in Table 2. The guards shall be securely attached and shall be adequately rigid to resist accidental contact with the blades.
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. Foor test voltage shall be applied as follows: 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, otherwise not.
Part 1 General requirements second fo. In the case of indirectly driven fans, the electric motor shall conform to the relevant Indian Standard, 1. As type test, this test should preferably be done immediately after the temperature-rise test. In the case of a double insulated fan, both basically insulated parts and live parts shall not be accessible to the standard test ceentrifugal.
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 ceentrifugal 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- ing on any contact iii Regulator resi- stance unit with conti- nuous runn- ing on any contact iv External fkr 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.
Search the history of over billion web pages on the Internet. It is positive when above and negative when below the ambi- ent pressure.
These are intended to prove general quali- ties and design of given type of fan. The openings – shall be flush with the duct and free from burrs and countersinks. Note — The trade name, voltage and the size of the fan shall be marked on associated regulator. This is also commonly known as wheel diameter. Part 1 Methods of testing performance’, issued by the British Stand- ards Institution.
This value shall fall within the range of specified tolerances. The most probable operating point for the fan shall be at the intersection of the fan characteri- stic and the system resistance line.
The following information in respect of an electric centrifugal fan shall be centrirugal by the purchaser on request: The fixed losses and copper losses shall be calculated in accordance with the details given in IS: For Reynolds numbers of and above, the coeffi- cient of discharge is 0″ and will cover the majority of fan tests.
The criterion of noise level may, therefore, be subject to an agreement between the manufac- turer and the purchaser.
Full text of “IS Centrifugal fans”
Such fans shall be specially marked. Details of conditions under which a licence for the use of the Standard Mark may be granted to manufacturers or cntrifugalmay be obtained from the Bureau of Indian Standards. It is always positive. This requirement is applicable for all positions in the normal use.
Note — The difference in pressures is the mean pressure when facing tube reading is employed. If the fan is specified for two or more distinct rated voltages with three or more supply terminals, the tests shall be carried out at the most unfavourable voltage.