Why does the power consumed is always constant even if a fan
speed is altered?
- 4 Answers
- 6343 Views
- I also Faced
- E-Mail Answers
Answer Posted / ramesh kumar k
A Fan is a constant power device... it always consumes the
same power even if the speed is altered because..
The fan basically operates at 230V and its rated current
inorder to decrease the fan speed we drop some voltage in
the resister so the voltage drop across the armature of the
fan is decreased... because some voltage is dropped in the
resistor itself...
Ex.
Approximately to say...
(this is only example to get understand..)
On 5 No. the Var = 230V & Vr = 0V at current I
On 4 No. the Var = 200V & Vr = 30V at current I
on 3 No. the Var = 150V & Vr = 80V at current I
so like this.... the voltage drop is always 230V only but
we force the less voltage to appear at armature to reduce
the speed of the fan by dropping some voltage in the
resister.
hence the power is always = 230V * Rated current
| Is This Answer Correct ? | 8 Yes | 2 No |
Post New Answer View All Answers
hi this is hema, r there any books in particular for the preparation of the APPSC-A.E.E(electrical), if so please mail me the names ... thank u .
please tell me how a surge protector work on a DC 48Volt.? please describe briefly.
How we can recongnise the phase displacement of transformer connection between primary & scondary...plzzz explain it with example.........
How much should be the load percentage for 15kva Inverter and Iinut & I output load with Calculations
Assuming that a dedicated neutral earthing transformer is provided for each GT generator, when the two generators are running in parallel, has consideration been given that the earth fault current from one generator stator winding be split between the two neutral earthing transformers? If so, what adverse impact will this have on the operation of the 59N and 27TN devices?
If the line voltage is reduced to 75% of its rated value then by what percentage current will reduce ?? 75% 25% 50% no change and why ?
some time we open engine breaker 8.0 MW load but plant not trip. and another time engine open 4.0 MW load engine trip why? individually engine breaker open & individually emergency stop why difference?
what is the synchronous timer ? and it applications.
what is mean by dual digital protection in the relay field?
why wire sizes are 3/29 or 7/29 and why not wire sizes are 2/29 or 6/29?
What is reverse power relay?
Transmission through a short line depends on
How to improve fuel cell in a distribution system?
Does the motor power displayed on the Motor name plate is the mechnical power motor delivers or it is consumed power from the system?
how can i improve the power factor in domestic (230v)
