Motor Current calculation

dear all,

i have small doubt in calculation & selection of proper motor

i have 2 application
1) solar tracker : used below actuator rated 24v , 4a,500 rpm used caary 800kg load.

power =24*4=96w
torque=(0.096*9550)/500=1.833n-m
here motor stop every 5 min

2) in project., air condition blower application continuous operation, motor designed  carry 48v . 5a rated ,axial load , radial load can carry upto 10kg.
the power:  p=5a*48v=240w
the torque: 0.24kw*9550/1550rpm=1.528nm (ps: torque required before: 0.59 nm) desired
but want run 2400 rpm
1.528nm*2400rpm/9550=0.384kw

because of change in wattage our stator got damage. bearing got disturb etc.

my question on here .
in first application running motor 500 rpm carrying 800kg of load
where in second case running motor 2400 rpm @48v , carry load of 900gm
why huge amount of current draw in above case??
what points doing in selection of motor???

in above case if increase wattage of motor can run motor.

that actuator rated @ 8000n , 2.8mm/s, 22.4w of mechanical
work @ full load.

you cannot scale power linearly speed in fan blower, air resistance goes
up square of velocity , work done cube of velocity.
thus going 1550rpm 2400rpm cause 4-fold increase in
load 890w, explains motor burning out.

the load of blower depends on speed/torque characteristics of fan,
the axial/radial loads purely strength of bearings support the
weight of fan (which not issue here).

balancing load gets more important speed (imbalance forces
go square of speed).

without knowing more blower motor hard more.

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