Specifications

138

13. ELECTRIC FAN AND ELECTRIC HAIR DRIER

13.1 Function:

A ceiling fan is a device suspended from the ceiling of a room, which employs hub-mounted

rotating paddles to circulated air.

13.2 Terminology: The terminology mentioned in B.I.S. No. 555-1979, B.I.S. 1189-1969 and

21312-193 is reproduced here;

i) Ceiling/Table Type fan: A propeller bladed fan having two or more blades, directly

driven by an electric motor, and intended for use with free inlet and outlet. It may be a

ceiling or a table mounted fan for wall or ceiling mounting.

ii) Blade Sweep: The diameter of the circle traced out by the extreme tips of the fan

blades.

iii) Size of Fan: The blade sweep in millimeters.

iv) Rating: The statement of the operating characteristics assigned to the fan by the

manufacturer when tested in accordance with B.I.S.

v) Rated Voltage range: The voltage range assigned to the fan by the manufacturer

expressed by its upper and lower limits and marked on it.

vi) Rated Speed: The rotational speed specified by the manufacturer at which the fan

develops the specified output at the rated frequency and rated voltage.

vii) Service Value: The air delivery in m

/min divided by the electrical power input to the

fan in Watts at the voltage and frequency specified for the test. In the event of the fan

comprising on oscillating mechanism, the electrical input in Watts is measured with

the fan under normal full speed conditions that is with oscillating mechanism in action,

whereas the air delivery is determined with the oscillating mechanism out of action.

13.3 Construction of Ceiling fan: The parts of the ceiling fan are shown in Fig.13.1 and 13.2.

The key components are the following;

Fig.13.1 - Internal Parts of ceiling fan

Fig.13.2 - External Parts of ceiling fan

1. Electric motor: Single phase capacitor start and run induction motor, rated at 230 V ± 10 %

at a frequency of 50 Hz, is normally used in ceiling fan. This motor has two parts namely stator

and rotor. The stator, made op laminated silicon steel, employs two windings called as starting

and running windings placed 90 degree electrical apart. The starting torque depends on sine of