hp : the measure of rate of work .one horse power is
equivalent to lifting 33,000 pounds to a height one afoot
in one minutes .the horse power of motor is expressed a
function of torque and rpm for motor the following
approximate formula may be used
hp =txrpm /5250
t-torque (in-ib.ft),rpm- revolutin per minute
hp -horse power
kw : the watts is relatively small unit of power the kilo
watts (kw) 1,000 watts is use where large unit of power
measurement are desirable
Horsepower is a north american standard for specifying
motors. KW is the European standard.
Low Voltage motors listed in KW will normally have 3
phase / 50 Hertz as there power supply.
Low Voltage motors listed in Horsepower will normally have
3 phase / 60 hertz as the power supply.
Unless the Engineers are mixing standards when specifying
It should be noted that the frequency of the supply power
will affect the RPMs of the motor. In north america 3/60
power the normal nominal RPMS are 3600, 1800, 1200, 900,
while in Europe (3/50) the normal nominal RPMS are 3000,
1500, 1000, 750.
I have a question, I visit 01 site and face a problem,
there is 2.5 ton Air Con working, when air con compressor
is running at that time rectifier voltages are increasing
upto 290-295 v and rectifier is giving main high alarm
(rectifier is APC single phase, before starting compressor
rectifier voltages was 230v. when air con is going off
rectifier voltages are decreasing smoothly at its actual
Load on Genset phases is this: Red-13.5 amp AC (Air Con
load), Yellow-1.7 amp AC (BTS lights etc.) and Blew-4 amp
AC (telecom system load),
Genset phase to phase and neutral to phase voltages are
These are 10 sites having same system and same rectifier
APC brand at every site 02 genset are working but the
problem is same at all these 10 sites.
What will be the reason behind???
IF 3 NOS.OF HEATERS,3KW CAPACITY EACH,1 NO.HEATER CONNECTED
IN R PHASE,1 IN Y PHASE AND 1 IN B PHASE.THEIR END POINTS
CONNECTED IN STAR.IF I CONNECT THIS STAR POINT TO NEUTRAL
OR DO NOT CONNECT TO NEUTRAL.WHAT WILL THE DIFFERENCE.
Bhel supervision exam question:
If 2 generators are working in a network. And if suddenly the
field of anyone generator weakens. What will happen in the network?
1. The generator will run as motor
2. The generator will run as motor in reverse direction
3. The generator will take lighter load
4. The generator will take more load
I find that underground strip-armoiured,4core,LT PVC cables
in an earthed power distribution sytem are occasionly found
in charred condition-with no trace of it except ash. Is
this because of no proper earth connection/continuity
(giving rising to high armour resistance)in the joint
enroute or because of insufficient capability (again due to
high armour resistance)of cable-armour to carry fault
current or due to neglected /unprotected overloading of the
cable or due to high armour currents caused by power thefts
where only phase(s) are unauthorisely tapped & at the point
of poer consumption earth terminal is established by
burring underground a not so good earthing rod (or using an
underground water pipe for the purpose)