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Calculate the power of a the lift motor

by taomay
Tags: lift, motor, power
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taomay
#1
May20-11, 08:53 AM
P: 2
Please help :

Calculate the power of a the lift motor,when is lift on a distance on a building site lift 400kg of brick50m to the top of a buiding in 24 seconds

Ans ?

Regards.
taomay
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May20-11, 09:11 AM
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taomay
#3
May20-11, 02:38 PM
P: 2
Quote Quote by taomay View Post
Please help :

Calculate the power of a the lift motor,when is lift on a distance on a building site lift 400kg of brick 50m to the top of a buiding in 24 seconds

Ans ?

Regards.
taomay

Ans :

mass= 400kg (convert mass to weight 1kg=9.81N (force of gravity on 1kg)

400x9.81=3924N
Workdone (j)= force xdistance
3924x50 =196200

Power = 196200 /24= 8175 W
convert to KW =8.175KW

shadow123
#4
Sep4-12, 02:49 PM
P: 1
Calculate the power of a the lift motor

Assuming that this is a cable driven lift and not a hydraulic lift, more data is required to calculate the HP required to lift the load:
Desired speed of lift
% of counterweighting
Hoisting machine eff.
acceleration rate and rate of change of acceleration rate (known as jerk rate)
Hoistway eff.
H.P. required = Speed (fpm) x capacity (lbs) x Percentage of uncounterweighted load (usually .4 to .5 / 33000) / overall eff.*
* this can actually range anywhere from 40% to 90% depending upon machine be geared or gearless, the roping type usually being 1:1 or 2:1 as well as the types of guide shoes (roller or slide).
If steep accelleration and jerk rates are required to meet a specific performance than a larger motor maybe required to meet those peak torque requirements.
To convert HP to KW, multiply the HP times .746


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