Plant Manufacturing and Building Facilities

1. L | C | LOGISTICS
PLANT MANUFACTURING AND BUILDING FACILITIES EQUIPMENT
Engineering-Book
ENGINEERING FUNDAMENTALS AND HOW IT WORKS
CONCEPTS, FORMULAS AND UNITS OF MEASUREMENT
September 2014
Supply Chain Manufacturing & DC Facilities Logistics Operations Planning Management
Expertise in Process Engineering Optimization Solutions & Industrial Engineering Projects Management

2. Glossary
HVAC (heating, ventilation, and air conditioning) The goal of HVAC design is to balance indoor
environmental comfort with other factors such as installation cost, ease of maintenance, and
energy efficiency
air changes per hour The number of times per hour that the volume of a specific room or
building is supplied or removed from that space by mechanical and natural ventilation
air conditioner An appliance, system, or mechanism designed to dehumidify and extract
heat from an area. Usually this term is reserved for smaller self contained units such as a
residential system.
air handling unit A central unit consisting of a blower, heating and cooling elements, filter
racks or chamber, dampers, humidifier, and other central equipment in direct contact with
the airflow. This does not include the ductwork through the building
British thermal unit (BTU) Any of several units of energy (heat) in the HVAC industry,
each slightly more than 1 kJ. One BTU is the energy required to raise one pound of
water one degree Fahrenheit

3. Glossary
The power of HVAC systems (the rate of cooling and dehumidifying or heating) is
sometimes expressed in BTU/hour instead of watts The unit watt, is defined as one joule
per second, and measures the rate of energy conversion or transfer
Chiller A device that removes heat from a liquid via a vapor-compression or absorption
refrigeration cycle
This cooled liquid flows through pipes in a building and passes through coils in air
handlers, fan-coil units, or other systems, cooling and usually dehumidifying the air in the
building.
Chillers are of two types; air-cooled or water-cooled. Air-cooled chillers are usually outside
and consist of condenser coils cooled by fan-driven air.
Water-cooled chillers are usually inside a building, and heat from these chillers is carried
by re-circulating water to a heat sink such as an outdoor cooling tower

4. Glossary
Coil Equipment that performs heat transfer to air when mounted inside an air handling unit
or ductwork. It is heated or cooled by electrical means or by circulating liquid or steam
within it.
Condenser A component in the basic refrigeration cycle that ejects or removes heat from
the system.
The condenser is the hot side of an air conditioner or heat pump. Condensers are heat
exchangers, and can transfer heat to air or to an intermediate fluid (such as water or an
aqueous solution of ethylene glycol) to carry heat to a distant sink, such as ground (earth
sink), a body of water, or air (as with cooling towers)
Evaporator A component in the basic refrigeration cycle that absorbs or adds
heat to the system. Evaporators can be used to absorb heat from air or from a
liquid. The evaporator is the cold side of an air conditioner or heat pump

5. Glossary
Damper A plate or gate placed in a duct to control air flow by increasing friction in the duct
Economizer An HVAC component that uses outside air, under suitable climate conditions,
to reduce required mechanical cooling. When the outside air’s enthalpy is less than the
required supply air during a call for cooling, an economizer allows a building’s mechanical
ventilation system to use up to the maximum amount of outside air
Enthalpy For a given sample of air, a measure of the total heat content (the sum of the heat
energy of the dry air and heat energy of the water vapor within it). It is typically used to
determine the amount of fresh outside air that can be added to re-circulated air for the
lowest cooling cost.
fan coil unit A small terminal unit that is often composed of only a blower and a
heating and/or cooling coil, as is often used in hotels, condominiums, or apartments
Flow A transfer of fluid volume per unit time

6. Glossary
fresh air intake An opening through which outside air is drawn into the building. This may
be to replace air in the building that has been exhausted by the ventilation system, or to
provide fresh air for combustion of fuel
Grille A facing across a duct opening, often rectangular in shape, containing multiple
parallel slots through which air may be delivered or withdrawn from a ventilated space. The
grille directs the air flow in a particular direction and prevents the passage of large items
heat gain / heat load / heat loss
Terms for the amount of cooling (heat gain) or heating (heat loss) needed to maintain
desired temperatures and humidity's in controlled air
Regardless of how well-insulated and sealed a building is, buildings gain heat from
sunlight, conduction through the walls, and internal heat sources such as people and
electrical equipment
Buildings lose heat through conduction during cold weather. Engineers use heat load
calculations to determine the HVAC needs of the space being cooled or heated

7. Glossary
intermediate fluid A liquid or gas used to transfer heat between two heat exchangers.
An intermediate fluid is used when the hot and cold fluids are too bulky (such as air) or
difficult to handle (such as halocarbon refrigerant) to directly transfer the heat
makeup air unit An air handler that conditions 100% outside air. Typically used in industrial
or commercial settings, or in "once-through" (blower sections that only blow air one-way
into the building), "low flow" (air handling systems that blow air at a low flow rate), or
"primary-secondary" (air handling systems that have an air handler or rooftop unit
connected to an add-on makeup unit or hood) commercial HVAC systems
Psychometric The study of the behavior of air-water vapor mixtures. Water vapor plays an
important role in energy transfer and human comfort in HVAC design
Radiation The transfer of heat directly from one surface to another (without heating the
intermediate air acting as a transfer mechanism).
Superheat The number of degrees a vapor is above its boiling point at a specific
pressure

8. Glossary
Sub-cooling The condition where liquid refrigerant is colder than the minimum temperature
required to keep it from boiling which would change it from a liquid to a gas phase.
Sub-cooling is the difference between its saturation temperature and the actual liquid
refrigerant temperature
terminal unit A small component that contains a heating coil, cooling coil, automatic
damper, or some combination of the three. Used to control the temperature of a single
room
variable air volume An HVAC system that has a stable supply-air temperature, and
varies the air flow rate to meet the temperature requirements
Compared to constant air volume systems, these systems conserve energy through
lower fan speeds during times of lower temperature control demand
Most new commercial buildings have VAV systems. VAVs may be bypass type or
pressure dependent. Pressure dependent type VAVs save energy while both types help
in maintaining temperature of the zone that it feeds
8 –

9. Glossary
In thermodynamics, entropy (usual symbol S) is a measure of the number of specific
ways in which a thermodynamic system may be arranged, often taken to be a measure of
disorder, or a measure of progressing towards thermodynamic equilibrium
The entropy of an isolated system never decreases, because isolated systems
spontaneously evolve towards thermodynamic equilibrium, the maximum entropy
Systems which are not isolated may decrease in entropy
Since entropy is a state function, the change in the entropy of a system is the same
whether a process going from one defined state to another is reversible or irreversible,
but irreversible processes increase the entropy of the environment
9 –
The change in entropy (ΔS) was originally defined for a thermodynamically
reversible process
which is found from the uniform thermodynamic temperature (T) of a closed system
dividing an incremental reversible transfer of heat into that system (dQ).

10. Glossary
Enthalpy is a defined thermodynamic potential, designated by the letter "H", that consists
of the internal energy of the system (U) plus the product of pressure (P) and volume (V) of
the system
The unit of measurement for enthalpy is the joule, but other historical, conventional units
are still in use, such as the British thermal unit and the calorie.
The total enthalpy, H, of a system cannot be measured directly
The same situation exists in classical mechanics: only a change or difference in energy
carries physical meaning
Enthalpy itself is a thermodynamic potential, so in order to measure the enthalpy of a
system, we must refer to a defined reference point; therefore what we measure is the
change in enthalpy, ΔH
The change ΔH is positive in endothermic reactions, and negative in heat-releasing
exothermic processes.
ΔH of a system is equal to the sum of non-mechanical work done on it and the heat
supplied to it
10 –

11. Glossary
One of the fundamental thermodynamic equations is the description of thermodynamic
work in analogy to mechanical work, or weight lifted through an elevation against gravity
Power, is the elevation of a weight to a certain height. The product of the weight
multiplied by the height to which it is raised.” With the inclusion of a unit of time
The state of a thermodynamic system is specified by a number of extensive quantities, the
most familiar of which are volume, internal energy, and the amount of each constituent
particle (particle numbers).
Extensive parameters are properties of the entire system, as contrasted with intensive
parameters which can be defined at a single point, such as temperature and pressure
The extensive parameters (except entropy) are generally conserved in some way as long
as the system is "insulated" to changes to that parameter from the outside
11 –

12. Glossary
In the case of energy, the statement of the conservation of energy is known as the first
law of thermodynamics, where is the infinitesimal increase in internal energy of the
system. Is the infinitesimal heat flow into the system and is the infinitesimal work
done by the system
In physical chemistry, positive work is conventionally considered work done on the
system rather than by the system, and the law is expressed as
The concept which governs the path that a thermodynamic system traces in state space
as it goes from one equilibrium state to another is that of entropy. The entropy is first
viewed as an extensive function of all of the extensive thermodynamic parameters
If we have a thermodynamic system in equilibrium, and we release some of the extensive
constraints on the system, there are many equilibrium states that it could move to
consistent with the conservation of energy, volume, etc.
12 –
.

13. Glossary
The second law of thermodynamics specifies that the equilibrium state that it moves to is
in fact the one with the greatest entropy. Once we know the entropy as a function of the
extensive variables of the system, we will be able to predict the final equilibrium state.
The entropy of an isolated system never decreases for an isolated system
A process within a given isolated system is said to be reversible if throughout the process
the entropy never increases (i.e. the entropy remains unchanged).
The third law of thermodynamics states that at the absolute zero of temperature, the
entropy is zero for a perfect crystalline structure when
The zeroth law says that systems that are in thermodynamic equilibrium with each other
have the same temperature. The law was actually the last of the laws to be formulated
consider a system composed of a number of k different types of particles and has the
volume as its only external variable. The fundamental thermodynamic relation may then
be expressed in terms of the internal energy as
13 –
The thermodynamic space has k+2 dimensions
The differential quantities (U, S, V, Ni) are all extensive
quantities

14. Glossary
Power in mechanical systems is the combination of forces and movement. In particular,
power is the product of a force on an object and the object's velocity, or the product of a
torque on a shaft and the shaft's angular velocity measured in radians per second
In fluid power systems such as hydraulic actuators, power is given by
where p is pressure in pascals, or N/m2 and Q is volumetric flow rate in m3/s in SI units
The instantaneous electrical power P delivered to a component is given by
P(t) is the instantaneous power, measured in watts (joules per second)
V(t) is the potential difference (or voltage drop) across the component, measured in volts
I(t) is the current through it, measured in amperes
If the component is a resistor with time-invariant voltage to current ratio, then
14 –
is the resistance, measured in ohms

15. Glossary
Electric power, like mechanical power, is the rate of doing work, measured in watts, and
represented by the letter P.
The term wattage is used colloquially to mean "electric power in watts."
The electric power in watts produced by an electric current I consisting of a charge of Q
coulombs every t seconds passing through an electric potential (voltage) difference of V is
Q is electric charge in coulombs
t is time in seconds
I is electric current in amperes
V is electric potential or voltage in volts
In the case of resistive (Ohmic, or linear) loads, Joule's law can be combined with Ohm's
law (V = I·R) to produce alternative expressions for the dissipated power
15 –
where R is the electrical resistance.

16. Glossary
In alternating current circuits, energy storage elements such as inductance and
capacitance may result in periodic reversals of the direction of energy flow
The portion of power flow that, averaged over a complete cycle of the AC waveform,
results in net transfer of energy in one direction is known as real power (also referred to as
active power)
That portion of power flow due to stored energy, that returns to the source in each cycle, is
known as reactive power
The real power P in watts consumed by a device is given by
Vp is the peak voltage in volts
Ip is the peak current in amperes
Vrms is the root-mean-square voltage in volts
Irms is the root-mean-square current in amperes
θ is the phase angle between the current and voltage sine waves
The ratio of real power to apparent power is a
number between 0 and 1
16 –

17. Glossary
Classical mechanics is concerned with the set of physical laws describing the motion of
bodies under the action of a system of forces
The study of the motion of bodies is an ancient one, making classical mechanics one of the
oldest and largest subjects in science, engineering and technology
It is also widely known as Newtonian mechanics
Isaac Newton proposed three laws of motion: the law of inertia, his second law of
acceleration (mentioned above), and the law of action and reaction; and hence laid the
foundations for classical mechanics
Newton also enunciated the principles of conservation of momentum and angular
momentum. In mechanics, Newton was also the first to provide the first correct scientific
and mathematical formulation of gravity in Newton's law of universal gravitation.
He demonstrated that these laws apply to everyday objects as well as to celestial objects.
In particular, Newton obtained a theoretical explanation of Kepler's laws of motion of the
planets.
17 –

18. Glossary
18 –
.
The velocity, or the rate of change of position with time, is
defined as the derivative of the position with respect to time:
The acceleration, or rate of change of velocity, is the
derivative of the velocity with respect to time (the second
derivative of the position with respect to time):
Some physicists interpret Newton's second law of motion as a definition of force and mass
The quantity mv is called the (canonical) momentum. The net force on a particle is thus
equal to the rate of change of the momentum of the particle with time
If a constant force F is applied to a particle that achieves a displacement Δr, the work
done by the force is defined as the scalar product of the force and displacement vectors

19. Glossary
The kinetic energy Ek of a particle of mass m travelling at speed v is given by
19 –
In special relativity, the momentum of a particle
is given by
where m is the particle's rest mass, v its
velocity, and c is the speed of light.
If v is very small compared to c, v2/c2 is
approximately zero, and so
Thus the Newtonian equation p = mv is an
approximation of the relativistic equation for
bodies moving with low speeds compared to
•Statics, the study of equilibrium and its relation to forces the speed of light
•Dynamics, the study of motion and its relation to forces
•Kinematics, dealing with the implications of observed
motions without regard for circumstances causing them

20. Glossary
Derived kinematic quantities Derived dynamic quantities
Velocity
Acceleration
Jerk
Angular velocity
Angular Acceleration
Momentum
Force
Impulse
Angular momentum
about a position point
r0, Most of the time we can set r0 = 0 if particles are orbiting about axes intersecting at a common point
20 –
Torque
Angular
impulse
Mechanical work

21. Glossary
Momentum is the "amount of translation"
For a rotating rigid body:
Angular momentum is the "amount of rotation":
Torque τ is also called moment of a force,
because it is the rotational analogue to force
Resultant force acts on a system at the
center of mass, equal to the rate of change
of momentum
Impulse is the change in momentum
Angular impulse is the change in
angular momentum
21 – Title of the document or activity name – Month XX, 2012 – Insert tab > Header/Footer
For constant force F:
For constant torque τ:
The work done W by an external agent which
exerts a force F (at r) and torque τ on an object
along a curved path C is Kinetic energy

22. Glossary
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel
around which rope or chain wraps
22 –
"Chain hoist" also describes a
hoist using a differential pulley
A compound pulley with two
different radii and teeth engage
an endless chain,
Allowing the exerted force to be
multiplied according to the ratio
of the radii.

23. Glossary
Consider the set of pulleys that form the moving block and the parts of the rope that
support this block
If there are p of these parts of the rope supporting the load W, then a force balance on
the moving block shows that the tension in each of the parts of the rope must be W/p
This means the input force on the rope is T=W/p. Thus, the block and tackle reduces the
input force by the factor p
The mechanical advantage of a pulley system can be analyzed using free body diagrams
which balance the tension force in the rope with the force of gravity on the load
In this case, a force balance on a free body that includes the load, W, and n supporting
sections of a rope with tension T, yields
23 –
the mechanical advantage of the system is equal to the
number of sections of rope supporting the load

24. Glossary
Differential pulley
is used to manually lift very heavy objects like car engines. It is operated by pulling upon
the slack section of a continuous chain that wraps around pulleys. The relative size of two
connected pulleys determines the maximum weight that can be lifted by hand.
It consists of two fixed pulleys of unequal radii that are attached to each other and
rotate together, a single pulley bearing the load, and an endless rope looped
around the pulleys. To avoid slippage, the rope is usually replaced by a chain, and
the connected pulleys by sprockets.
24 –

25. Glossary
The two sections of chain carrying the single pulley exert opposing and unequal torques
on the connected pulleys, such that only the difference of these torques has to be
compensated manually by pulling the loose part of the chain.
This leads to a mechanical advantage: the force needed to lift a load is only a fraction of
the load's weight.
At the same time, the distance the load is lifted is smaller than the length of chain pulled
by the same factor.
This factor (the mechanical advantage MA) depends on the relative difference of the radii
r and R of the connected. The effect on the forces and distances is quantitatively
The difference in radii can be made very small, making the mechanical advantage of this
pulley system very large. In the extreme case of zero difference in radii, MA becomes
infinite, thus no force (besides friction) is needed to move the chain, but moving the chain
will no longer lift the load, when r is zero, the system becomes with a MA = 2
25 –

26. Glossary
A belt and pulley system is characterized by two or more pulleys in common to a belt. This
allows for mechanical power, torque, and speed to be transmitted across axles. If the
pulleys are of differing diameters, a mechanical advantage is realized
A belt drive is analogous to that of a chain drive, however a belt sheave may be smooth
(devoid of discrete interlocking members as would be found on a chain sprocket, spur
gear, or timing belt) so that the mechanical advantage is approximately given by the ratio
of the pitch diameter of the sheaves only, not fixed exactly by the ratio of teeth as with
gears and sprockets.
26 –

27. Glossary
27 –
The gear ratio of a gear train, also known as its speed
ratio, is the ratio of the angular velocity of the input gear to
the angular velocity of the output gear
The gear ratio can be calculated directly from the
numbers of teeth on the gears in the gear train
The torque ratio of the gear train, also known as its
mechanical advantage, is determined by the gear ratio
The speed ratio and mechanical advantage are defined
so they yield the same number in an ideal linkage

28. Glossary
A gear train is formed by mounting gears on a frame so that the teeth of the gears engage
Gear teeth are designed to ensure the pitch circles of engaging gears roll on each other
without slipping, providing a smooth transmission of rotation from one gear to the next
28 –
Gear teeth are designed so that the number of teeth on a gear is
proportional to the radius of its pitch circle, and so that the pitch
circles of meshing gears roll on each other without slipping.
The speed ratio for a pair of meshing gears can be computed from ratio of the radii of the
pitch circles and the ratio of the number of teeth on each gear
The velocity v of the point of contact on the pitch circles is the same on both gears,
and is given by

29. Glossary
where input gear A has radius rA and meshes with output gear B of radius rB
where NA is the number of teeth on the input gear and NB on the output gear
The mechanical advantage of a pair of meshing gears for which the input gear has NA
teeth and the output gear has NB teeth is given by MA
This shows that if the output gear GB has more teeth than the input gear GA, then the gear
train amplifies the input torque
And, if the output gear has fewer teeth than the input gear, then the gear train reduces
the input torque
If the output gear of a gear train rotates more slowly than the input gear, then the gear
train is called a speed reducer
In this case, because the output gear must have more teeth than the input gear, the
speed reducer amplifies the input torque.
29 –

30. Glossary
Speed ratio. Gear teeth are distributed along the circumference of the pitch circle so that
the thickness t of each tooth and the space between neighboring teeth are the same
The pitch p of a gear, which is the distance between equivalent points on neighboring
teeth along the pitch circle, is equal to twice the thickness of a tooth,
The pitch of a gear GA can be computed from the number of teeth NA and the radius rA of
its pitch circle
In order to mesh smoothly two gears GA and GB must have the same sized teeth and
therefore they must have the same pitch p, which means
This equation shows that the ratio of the circumference, the diameters and the radii of
two meshing gears is equal to the ratio of their number of teeth,
The speed ratio of two gears rolling without slipping on their pitch circles is given by,
30 –

31. Glosary
Calculating power
Watt determined that a horse could turn a mill wheel 144 times in an hour (or 2.4 times a
minute). The wheel was 12 feet in radius; therefore, the horse travelled 2.4 × 2π × 12
feet in one minute. Watt judged that the horse could pull with a force of 180 pounds. So:
This was rounded to an even 33,000 ft·lbf/min.
If torque and angular speed are known, the power may be calculated. The relationship
when using a coherent system of units (such as SI) is simply
The constant 5252 is the rounded value of (33,000 ft·lbf/min)/(2π rad/rev).
When torque is in inch pounds:
The constant 63,025 is the rounded value of (33,000 ft·lbf/min) × (12 in/ft)/(2π rad/rev).
31 –

32. Glosary
The following definitions have been widely used:
Mechanical horsepower
hp(I) ≡ 33,000 ft-lbf/min
32 –
= 550 ft·lbf/s
≈ 17,696 lbm·ft2/s3
= 745.69987158227022 W
Metric horsepower
hp(M) - also PS, ''cv, hk, pk, ks or ch
≡ 75 kgf·m/s
≡ 735.49875 W
Electrical horsepower
hp(E) ≡ 746 W
Boiler horsepower
hp(S) ≡ 33,475 BTU/h
= 9,812.5 W
Hydraulic horsepower
= flow rate (US gal/min) × pressure (psi) × 7/12,000 = 550 ft·lbf/s
= flow rate (US gal/min) × pressure (psi) / 1714 = 745.699 W

33. Glosary
Torque converter is generally a type of fluid coupling (but also being able to
33 –
multiply torque) that is used to transfer rotating power from a
prime mover, such as an internal combustion engine or electric
motor, to a rotating driven load
The torque converter normally takes the place of a mechanical
clutch in a vehicle with an automatic transmission, allowing the
load to be separated from the power source
It is usually located between the engine's flexplate and the
transmission.
The key characteristic of a torque converter is its ability to
multiply torque when there is a substantial difference between
input and output rotational speed, thus providing the equivalent
of a reduction gear

34. Glosary
As with a basic fluid coupling the theoretical torque capacity of a converter is proportional to
34 –
where is the mass density of the fluid (kg/m³),
and is the impeller speed (rpm),
is the diameter(m)
A torque converter cannot achieve 100 percent coupling efficiency.
The classic three element torque converter has an efficiency curve that resembles ∩:
zero efficiency at stall, generally increasing efficiency during the acceleration phase and
low efficiency in the coupling phase
Typical stall torque multiplication ratios range from 1.8:1 to 2.5:1 for most automotive
applications
Specialized converters designed for industrial, rail, or heavy marine power transmission
systems are capable of as much as 5.0:1 multiplication

35. Glosary
35 –
Power
Motor Velocity (rpm)
3450 2000 1000 500
Torque
hp kW (in lbf) (ft lbf) (Nm) (in lbf) (ft lbf) (Nm) (in lbf) (ft lbf) (Nm) (in lbf) (ft lbf) (Nm)
1 0.75 18 1.5 2.1 32 2.6 3.6 63 5.3 7.1 126 10.5 14.2
1.5 1.1 27 2.3 3.1 47 3.9 5.3 95 7.9 10.7 189 15.8 21.4
2 1.5 37 3.0 4.1 63 5.3 7.1 126 10.5 14.2 252 21.0 28.5
3 2.2 55 4.6 6.2 95 7.9 10.7 189 15.8 21.4 378 31.5 42.7
5 3.7 91 7.6 10 158 13.1 18 315 26.3 36 630 52.5 71
7.5 5.6 137 11 15 236 20 27 473 39 53 945 79 107
10 7.5 183 15 21 315 26 36 630 53 71 1260 105 142
15 11 274 23 31 473 39 53 945 79 107 1891 158 214
20 15 365 30 41 630 53 71 1260 105 142 2521 210 285
25 19 457 38 52 788 66 89 1576 131 178 3151 263 356
30 22 548 46 62 945 79 107 1891 158 214 3781 315 427
40 30 731 61 83 1260 105 142 2521 210 285 5042 420 570
50 37 913 76 103 1576 131 178 3151 263 356 6302 525 712
60 45 1096 91 124 1891 158 214 3781 315 427 7563 630 855
70 52 1279 107 145 2206 184 249 4412 368 499 8823 735 997
80 60 1461 122 165 2521 210 285 5042 420 570 10084 840 1140
90 67 1644 137 186 2836 236 321 5672 473 641 11344 945 1282
100 75 1827 152 207 3151 263 356 6302 525 712 12605 1050 1425
125 93 2283 190 258 3939 328 445 7878 657 891 15756 1313 1781
Example - Electrical Motor
Torque
Torque from an electrical motor
with
100 hp and speed 1000 rpm
can be calculated as
T = (100 hp) 63025 / (1000 rpm)
= 6303 (in lbf)
To convert to foot pound-force -
divide the torque by 12.

36. Glosary
Electrical Motor Torque Equation
Torque can be calculated in Imperial units as
T = Php 63025 / n (1)
where
T = torque (in lbf)
Php = horsepower delivered by the electric motor
n = revolution per minute (rpm)
Alternatively
Tft = Php 5252 / n (1b)
where
Tft = torque (ft lbf)
•1 ft lbf = 1.356 Nm
Torque can be calculated in SI units as
T = PW 9.554 / n (1)
where
T = torque (Nm)
PW = power (watts)
n = revolution per minute (rpm)
36 –

37. Glosary
Calculating Motor Speed:
A squirrel cage induction motor is a constant speed device. It
cannot operate for any length of time at speeds below those shown
on the nameplate without danger of burning out.
To Calculate the speed of a induction motor, apply this
formula:
Srpm = 120 x F
37 –
P
Srpm = synchronous revolutions per minute.
120 = constant
F = supply frequency (in cycles/sec)
P = number of motor winding poles
Example: What is the synchronous of a motor having 4 poles
connected to a 60 hz power supply?
Srpm = 120 x F
P
Srpm = 120 x 60
4
Srpm = 7200
4
Srpm = 1800 rpm

38. Glosary
Calculating Braking Torque:
Full-load motor torque is calculated to determine the required
braking torque of a motor.
To Determine braking torque of a motor, apply this formula:
T = 5252 x HP
rpm
T = full-load motor torque (in lb-ft)
5252 = constant (33,000 divided by 3.14 x 2 = 5252)
HP = motor horsepower
rpm = speed of motor shaft
Example: What is the braking torque of a 60 HP, 240V motor
rotating at 1725 rpm?
T = 5252 x HP
rpm
T = 5252 x 60
1725
T = 315,120
1725
T = 182.7 lb-ft
38 –

39. Glosary
Calculating Work:
Work is applying a force over a distance. Force is any cause
that changes the position, motion, direction, or shape of an
object. Work is done when a force overcomes a resistance.
Resistance is any force that tends to hinder the movement of
an object.If an applied force does not cause motion the no
work is produced.
To calculate the amount of work produced, apply this formula:
W = F x D
W = work (in lb-ft)
F = force (in lb)
D = distance (in ft)
Example: How much work is required to carry a 25 lb bag of
groceries vertically from street level to the 4th floor of a
building 30' above street level?
W = F x D
W = 25 x 30
W = 750 -lb
39 –

40. Glosary
Calculating Torque:
Torque is the force that produces rotation. It causes an object to rotate. Torque
consist of a force acting on distance. Torque, like work, is measured is pound-feet
(lb-ft). However, torque, unlike work, may exist even though no movement occurs.
To calculate torque, apply this formula:
T = F x D
T = torque (in lb-ft)
F = force (in lb)
D = distance (in ft)
Example: What is the torque produced by a 60 lb force pushing on a 3' lever arm?
T = F x D
T = 60 x 3
T = 180 lb ft
40 –

41. Glosary
Calculating Full-load Torque:
Full-load torque is the torque to produce the rated power at full speed of the motor. The amount of
torque a motor produces at rated power and full speed can be found by using a horsepower-to-torque
41 –
conversion chart. When using the conversion chart, place a straight edge along the two
known quantities and read the unknown quantity on the third line.
To calculate motor full-load torque, apply this formula:
T = HP x 5252
rpm
T = torque (in lb-ft)
HP = horsepower
5252 = constant
rpm = revolutions per minute
Example: What is the FLT (Full-load torque) of a 30HP motor operating at 1725 rpm?
T = HP x 5252
rpm
T = 30 x 5252
1725
T = 157,560
1725
T = 91.34 lb-ft

42. Glosary
Calculating Horsepower:
Electrical power is rated in horsepower or watts. A horsepower is a unit of power equal to 746 watts or
33,0000 lb-ft per minute (550 lb-ft per second). A watt is a unit of measure equal to the power
produced by a current of 1 amp across the potential difference of 1 volt. It is 1/746 of 1 horsepower.
The watt is the base unit of electrical power. Motor power is rated in horsepower and watts.
Horsepower is used to measure the energy produced by an electric motor while doing work.
To calculate the horsepower of a motor when current and efficiency, and voltage are known,
apply this formula:
HP = V x I x Eff
42 –
746
HP = horsepower
V = voltage
I = curent (amps)
Eff. = efficiency
Example: What is the horsepower of a 230v motor pulling 4 amps and having 82% efficiency?
HP = V x I x Eff
746
HP = 230 x 4 x .82
746
HP = 754.4
746
HP = 1 Hp
Eff = efficiency / HP = horsepower / V = volts / A = amps / PF = power factor

43. Glosary
43 –
Horsepower Formulas
To Find Use Formula
Example
Given Find Solution
HP HP = I X E X Eff.
746
240V, 20A, 85%
Eff. HP
HP = 240V x 20A
x 85%
746
HP=5.5
I I = HP x 746
E X Eff x PF
10HP, 240V,
90% Eff., 88% PF I
I = 10HP x 746
240V x 90% x
88%
I = 39 A
To calculate the horsepower of a motor when the speed and torque are known, apply this formula:
HP = rpm x T(torque)
5252(constant)
Example: What is the horsepower of a 1725 rpm motor with a FLT 3.1 lb-ft?
HP = rpm x T
5252
HP = 1725 x 3.1
5252
HP = 5347.5
5252
HP = 1 hp

44. Glosary
Calculating Synchronous Speed:
AC motors are considered constant speed motors. This is because the synchronous speed of an
induction motor is based on the supply frequency and the number of poles in the motor winding.
Motor are designed for 60 hz use have synchronous speeds of 3600, 1800, 1200, 900, 720, 600, 514,
and 450 rpm.
To calculate synchronous speed of an induction motor, apply this formula:
rpmsyn = 120 x f
44 –
Np
rpmsyn = synchronous speed (in rpm)
f = supply frequency in (cycles/sec)
Np = number of motor poles
Example: What is the synchronous speed of a four pole motor operating at 50 hz.?
rpmsyn = 120 x f
Np
rpmsyn = 120 x 50
4
rpmsyn = 6000
4
rpmsyn = 1500 rpm

45. Glosary
Torque in
45 –
lb.ft. =
HP x 5250
rpm
HP =
Torque x
rpm
5250
rpm =
120 x
Frequency
No. of Poles
Rules Of Thumb (Approximation)
At 1800 rpm, a motor develops a 3 lb.ft. per hp
At 1200 rpm, a motor develops a 4.5 lb.ft. per hp
At 575 volts, a 3-phase motor draws 1 amp per hp
At 460 volts, a 3-phase motor draws 1.25 amp per hp
At 230 volts a 3-phase motor draws 2.5 amp per hp
At 230 volts, a single-phase motor draws 5 amp per hp
At 115 volts, a single-phase motor draws 10 amp per hp
Mechanical Formulas

46. Glosary
Synchronous Speed, Frequency And Number Of Poles Of AC Motors
Relation Between Horsepower, Torque, And Speed
46 –
t =
High Inertia Loads
WK2 x rpm
308 x T av.
WK2 = inertia in lb.ft.2
t = accelerating time in sec.
T = Av. accelerating torque lb.ft..
Temperature Conversion
Deg C = (Deg F - 32) x 5/9
Deg F = (Deg C x 9/5) + 32
inertia reflected to motor = Load Inertia (Load rpm)
Motor rpm 2
ns =
120 x f
P
f =
P x ns
120
P =
120 x f
ns
HP = T x n
5250 T = 5250 HP
n n = 5250 HP
T
% Slip =
ns - n
ns
x 100
Motor Slip

47. Glosary
Code KVA/HP Code KVA/HP Code KVA/HP Code KVA/HP
A 0-3.14 F 5.0 -5.59 L 9.0-9.99 S 16.0-17.99
B 3.15-3.54 G 5.6 -6.29 M 10.0-11.19 T 18.0-19.99
C 3.55-3.99 H 6.3 -7.09 N 11.2-12.49 U 20.0-22.39
D 4.0 -4.49 I 7.1 -7.99 P 12.5-13.99 V 22.4 & Up
E 4.5 -4.99 K 8.0 -8.99 R 14.0-15.99
Symbols
I = current in amperes
E = voltage in volts
KW = power in kilowatts
KVA = apparent power in kilo-volt-amperes
HP = output power in horsepower
N = motor speed in revolutions per minute (RPM)
Ns = synchronous speed in revolutions per minute (RPM)
P = number of poles
F = frequency in cycles per second (CPS)
T = torque in pound-feet
EFF = efficiency as a decimal
PF = power factor as a decimal
47 –

48. Glosary
Equivalent Inertia
In mechanical systems, all rotating parts do not usually operate at the same speed. Thus, we need to
determine the "equivalent inertia" of each moving part at a particular speed of the prime mover
The total equivalent WK2 for a system is the sum of the WK2 of each part, referenced to prime mover
speed
The equation says:
WK2
48 –
EQ = WK2
part
(Npart) 2
Nprime mover
This equation becomes a common denominator on which other calculations can be based. For variable-speed
devices, inertia should be calculated first at low speed
Let's look at a simple system which has a prime mover (PM), a reducer and a load
WK2 = 100 lb.ft.2 WK2 = 900 lb.ft.2
(as seen at output shaft) WK2 = 27,000 lb.ft.2
PRIME MOVER 3:1 GEAR REDUCER LOAD
The formula states that the system WK2 equivalent is equal to the sum of WK2
parts at the prime mover's RPM

49. Glosary
or in this case:
49 –
WK2
EQ = WK2
pm +
WK2
Red.
(Red. RPM)
PM RPM 2 + WK2
Load (Load RPM)
PM RPM 2
Note: reducer RPM = Load RPM
EQ = WK2
pm + WK2
Red. (1)
WK2
Load (1)
3 2 + WK2
3 2
The WK2 equivalent is equal to the WK2 of the prime mover, plus the WK2 of the load. This is equal to the WK2 of the
prime mover, plus the WK2 of the reducer times (1/3)2, plus the WK2 of the load times (1/3)2
This relationship of the reducer to the driven load is expressed by the formula given earlier:
WK2
EQ = WK2
part
(Npart)
Nprime mover
2
In other words, when a part is rotating at a speed (N) different from the prime mover, the WK2
EQ is equal to the WK2 of
the part's speed ratio squared

50. Glosary
In the example, the result can be obtained as follows:
The WK2 equivalent is equal to:
WK2
Finally:
50 –
EQ = 100 lb.ft.2 + 900 lb.ft.2 (1)
3 2 + 27,000
lb.ft.2
(1
)32
WK2
EQ = lb.ft.2
pm + 100 lb.ft.2
Red + 3,000 lb.ft2
Load
WK2
EQ = 3200 lb.ft.2
The total WK2 equivalent is that WK2 seen by the prime mover at its speed.

51. Glosary
51 –
To Find
Alternating Current
Single-Phase Three-Phase
Amperes when horsepower is known HP x 746
E x Eff x pf
HP x 746
1.73 x E x Eff x pf
Amperes when kilowatts are known Kw x 1000
E x pf
Kw x 1000
1.73 x E x pf
Amperes when kva are known Kva x 1000
E
Kva x 1000
1.73 x E
Kilowatts I x E x pf
1000
1.73 x I x E x pf
1000
Kva I x E
1000
1.73 x I x E
1000
Horsepower = (Output) I x E x Eff x pf
746
1.73 x I x E x Eff x pff
746
Electrical Formulas
I = Amperes; E = Volts; Eff = Efficiency; pf = Power Factor; Kva = Kilovolt-amperes; Kw = Kilowatts

52. Glosary
Locked Rotor Current (IL) From Nameplate Data
Three Phase: IL = 577 x HP x KVA/HP
Effect Of Line Voltage On Locked Rotor Current (IL) (Approx.)
52 –
E
See: KVA/HP Chart
Single Phase: IL = 1000 x HP x KVA/HP
E
EXAMPLE: Motor nameplate indicates 10 HP, 3 Phase, 460 Volts, Code F
IL = 577 x 10 x (5.6 or 6.29)
460
IL = 70.25 or 78.9 Amperes (possible range)
IL @ ELINE = IL @ EN/P
x
ELINE
EN/P
EXAMPLE: Motor has a locked rotor current (inrush of 100 Amperes (IL) at the rated nameplate voltage (EN/P) of 230 volts.
What is IL with 245 volts (ELINE) applied to this motor?
IL @ 245 V. = 100 x 254V/230V
IL @ 245V. = 107 Amperes

53. Glosary
Basic Horsepower Calculations
Horsepower is work done per unit of time. One HP equals 33,000 ft-lb of work per minute. When work is
done by a source of torque (T) to produce (M) rotations about an axis, the work done is:
radius x 2 x rpm x lb. or 2 TM
When rotation is at the rate N rpm, the HP delivered is:
HP = radius x 2 x rpm x lb.
Where:
53 –
33,000 = TN
5,250
For vertical or hoisting motion HP = W x S
33,000 x E
W = total weight in lbs. to be raised by motor
S = hoisting speed in feet per minute
E = overall mechanical efficiency of hoist and gearing. For purposes of estimating
E = .65 for eff. of hoist and connected gear.

54. Glosary
For fans and blowers:
HP = Volume (cfm) x Head (inches of water)
For purpose of estimating, the eff. of a fan or blower may be assumed to be 0.65.
54 –
6356 x Mechanical Efficiency of Fan
Note: Air Capacity (cfm) varies directly with fan speed. Developed Pressure varies with square of fan speed.
Hp varies with cube of fan speed.
HP
=
Volume (cfm) x Pressure (lb. Per sq. ft.)
3300 x Mechanical Efficiency of Fan
HP = Volume (cfm) x Pressure (lb. Per sq. in.)
229 x Mechanical Efficiency of Fan
For pumps: HP = GPM x Pressure in lb. Per sq. in. x Specific Grav.
1713 x Mechanical Efficiency of Pump
HP =
GPM x Total Dynamic Head in Feet x
S.G.
3960 x Mechanical Efficiency of Pump
where Total Dynamic Head = Static Head + Friction Head
For estimating, pump efficiency may be assumed at 0.70

55. Glosary
Accelerating Torque
The equivalent inertia of an adjustable speed drive indicates the energy required to keep the system running.
However, starting or accelerating the system requires extra energy.
The torque required to accelerate a body is equal to the WK2 of the body, times the change in RPM, divided by 308
times the interval (in seconds) in which this acceleration takes place:
ACCELERATING TORQUE
55 –
=
WK2N (in lb.ft.)
308t
N = Change in RPM
W = Weight in Lbs.
K = Radius of gyration
t = Time of acceleration (secs.)
WK2 = Equivalent Inertia
308 = Constant of proportionality
Where:
TAcc = WK2N
308t
The constant (308) is derived by transferring linear motion to angular motion, and considering acceleration due to
gravity. If, for example, we have simply a prime mover and a load with no speed adjustment

56. Glosary
Example 1 PRIME LOADER LOAD
56 –
WK2 = 200 lb.ft.2 WK2 = 800 lb.ft.2 The WK2
EQ is determined as before:
WK2
EQ = WK2
pm + WK2
Load
WK2
EQ = 200 + 800
WK2
EQ = 1000 ft.lb.2
If we want to accelerate this load to 1800 RPM in 1 minute, enough information is
available to find the amount of torque necessary to accelerate the load.
The formula states:
TAcc = WK2
EQN
308t
or 1000 x 1800
308 x 60 or 1800000
18480
TAcc = 97.4 lb.ft
In other words, 97.4 lb.ft. of torque must be applied to get this load turning at 1800 RPM, in 60 seconds.
Note that TAcc is an average value of accelerating torque during the speed change under consideration. If a more
accurate calculation is desired, the following example may be helpful.
Example 2
The time that it takes to accelerate an induction motor from one speed to another may be found from the following equation:
t = WR2 x change in rpm
308 x T
T = Average value of accelerating torque during the speed change under consideration.
t = Time the motor takes to accelerate from the initial speed to the final speed.
WR2 = Flywheel effect, or moment of inertia, for the driven machinery plus the motor rotor in lb.ft.2 (WR2 of driven
machinery must be referred to the motor shaft).

57. Glosary
The Application of the above formula will now be considered by means of an example
Figure A shows the speed-torque curves of a squirrel-cage induction motor and a blower which it drives.
At any speed of the blower, the difference between the torque which the motor can deliver at its shaft
and the torque required by the blower is the torque available for acceleration
Reference to Figure A shows that the accelerating torque may vary greatly with speed. When the
speed-torque curves for the motor and blower intersect there is no torque available for acceleration.
The motor then drives the blower at constant speed and just delivers the torque required by the load
In order to find the total time required to accelerate the motor and blower, the area between the motor
speed-torque curve and the blower speed-torque curve is divided into strips, the ends of which
approximate straight lines. Each strip corresponds to a speed increment which takes place within a
definite time interval
The solid horizontal lines in Figure A represent the boundaries of strips; the lengths of the broken lines
the average accelerating torques for the selected speed intervals. In order to calculate the total
acceleration time for the motor and the direct-coupled blower it is necessary to find the time required to
accelerate the motor from the beginning of one speed interval to the beginning of the next interval and
add up the incremental times for all intervals to arrive at the total acceleration time
If the WR2 of the motor whose speed-torque curve is given in Figure A is 3.26 ft.lb.2 and the WR2 of the
blower referred to the motor shaft is 15 ft.lb.2, the total WR2 is 15 + 3.26 = 18.26 ft.lb.2
57 –

58. Glosary
And the total time of acceleration is:
WR2
308 X [
58 –
rpm1
T1
+
rpm2
T2
+
rpm3
T3
+ - - - - -
- - - - +
rpm9
T9
]
t =
18.2
6
308
X [ 150
46 + 150
48 + 300
47 + 300
43.8 + 200
39.8 + 200
36.4 + 300
32.8 + 100
29.6 + 40
11 ]
t = 2.75 sec. Accelerating Torques
T1 = 46 lb.ft. T4 = 43.8 lb.ft. T7 = 32.8 lb.ft.
T2 = 48 lb.ft. T5 = 39.8 lb.ft. T8 = 29.6 lb.ft.
T3 = 47 lb.ft. T6 = 36.4 lb.ft. T9 = 11 lb.ft.
Curves used to determine time required to
accelerate induction motor and blower

59. Glosary
In order for a duty cycle to be checked out, the duty cycle information must include the following:
Inertia reflected to the motor shaft.
Torque load on the motor during all portions of the duty cycle including starts, running time, stops or
reversals.
Accurate timing of each portion of the cycle.
Information on how each step of the cycle is accomplished. For example, a stop can be by coasting,
mechanical braking, DC dynamic braking or plugging. A reversal can be accomplished by plugging, or
the motor may be stopped by some means then re-started in the opposite direction.
When the motor is multi-speed, the cycle for each speed must be completely defined, including the
method of changing from one speed to another.
Any special mechanical problems, features or limitations
59 –

60. Glosary
Duty cycle refers to the detailed description of a work cycle that repeats in a specific time period
This cycle may include frequent starts, plugging stops, reversals or stalls
These characteristics are usually involved in batch-type processes and may include tumbling barrels,
certain cranes, shovels and draglines, dampers, gate- or plow-positioning drives, drawbridges, freight
and personnel elevators, press-type extractors, some feeders,presses of certain types, hoists,
indexers, boring machines,cinder block machines, keyseating, kneading, car-pulling, shakers (foundry
or car), swaging and washing machines, and certain freight and passenger vehicles
The list is not all-inclusive. The drives for these loads must be capable of absorbing the heat
generated during the duty cycles
Adequate thermal capacity would be required in slip couplings, clutches or motors to accelerate or
plug-stop these drives or to withstand stalls
It is the product of the slip speed and the torque absorbed by the load per unit of time which
generates heat in these drive components
All the events which occur during the duty cycle generate heat which the drive components must
dissipate.
60 –

61. Conversion Units
61 –

62. Conversion Units
62 –

63. Conversion Units
63 –

64. Conversion Units
64 –

65. Conversion Units
65 –

66. Conversion Units
66 –
1 mile per hour (mph)
≅
1.46666667 feet per second (fps)
1 mile per hour (mph) = 1.609344 kilometers per hour
1 knot
≅
1.150779448 miles per hour
1 foot per second
≅
0.68181818 miles per hour (mph)
1 kilometer per hour
≅
0.62137119 miles per hour (mph)
1 square foot = 144 square inches
1 square foot = 929.0304 square centimeters
1 square yard = 9 square feet
1 square meter
≅
10.7639104 square feet
1 centimeter (cm)
=
10 millimeters (mm)
1 inch
=
2.54 centimeters (cm)
1 foot
=
0.3048 meters (m)
1 foot
=
12 inches
1 yard
=
3 feet
1 meter (m)
=
100 centimeters (cm)
1 meter (m)
≅
3.280839895 feet
1 furlong
=
660 feet
1 kilometer (km)
=
1000 meters (m)
1 kilometer (km)
≅
0.62137119 miles
1 mile
=
5280 ft
1 mile
=
1.609344 kilometers (km)
1 nautical mile
=
1.852 kilometers (km)
1 pound (lb)
=
0.45359237 kilograms (kg)

67. Conversion Units
67 –
Some Formulas
Area of Square Side Squared
Area of Circle 3.1415927 x Radius Square
Area of Sphere 4 x 3.1415927 x Radius Squared
Area of Parallelogram Base x Height
Circumference of Circle 2 x 3.1415927 x Radius
Volume of Rectangular Box Length x Width x Height
Volume of Cone 1/3 x 3.1415927 x Radius Squared x Height
Volume of Cylinder 3.1415927 x Radius Squared x Height
Volume of Sphere 4 x 3.1415927 x Radius Cubed ÷ 3
Volume of Cube Side Cubed
a = area
c = circumference
v = volume
sq = square
cu = cubic
r = radius
d = diameter
l = length
w = width
h = height
s = side
Pi = 3.1415927 (approx)

68. Conversion Units
68 –
Given Multiply by To Find
Length [L]
Foot (ft) 0.304800 Meter (m)
Inch (in) 25.4000 Millimeter (mm)
Mile (mi) 1.609344 Kilometer (km)
Area [L]2
ft2 0.092903 m2
in2 645.16 mm2
in2 6.45160 cm2
Volume [L]3 & Capacity
in3 16.3871 cm3
ft3 0.028317 m3
ft3 7.4805 Gallon
ft3 28.3168 Liter (l)
Gallon 3.785412 Liter

69. Conversion Units
69 –
Energy, Work or Heat [M] [L]2 [t]-2
Btu 1.05435 kJ
Btu 0.251996 kcal
Calories (cal) 4.184* Joules (J)
ft-lbf 1.355818 J
ft-lbf 0.138255 kgf-m
hp-hr 2.6845 MJ
KWH 3.600 MJ
m-kgf 9.80665* J
N-m 1. J
Flow Rate [L]3 [t]-1
ft3/min 7.4805 gal/min
ft3/min 0.471934 l/s
gal/min 0.063090 l/s

70. Conversion Units
70 –
Force or Weight [M] [L] [t]-2
kgf 9.80665* Newton (N)
lbf 4.44822 N
lbf 0.453592 Kgf
Fracture Toughness
ksi sqr(in) 1.098800 MPa sqr(m)
Heat Content
Btu/lbm 0.555556 cal/g
Btu/lbm 2.324444 J/g
Btu/ft3 0.037234 MJ/m3
Heat Flux
Btu/hr-ft2 7.5346 E-5 cal/s-cm2
Btu/hr-ft2 3.1525 W/m2
cal/s-cm2 4.184* W/cm2

71. Conversion Units
71 –
Mass Density [M] [L]-3
lbm/in3 27.68 g/cm3
lbm/ft3 16.0184 kg/m3
Power [M] [L]2 [t]-3
Btu/hr 0.292875 Watt (W)
ft-lbf/s 1.355818 W
Horsepower (hp) 745.6999 W
Horsepower 550.* ft-lbf/s
Pressure (fluid) [M] [L]-1 [t]-2
Atmosphere (atm) 14.696 lbf/in2
atm 1.01325 E5* Pascal (Pa)
lbf/ft2 47.88026 Pa
lbf/in2 27.6807 in. H20 at 39.2°F

72. Conversion Units
72 –
Stress [M] [L]-1 [t]-2
kgf/cm2 9.80665 E-2* MPa
ksi 6.89476 MPa
N/mm2 1. MPa
kgf/mm2 1.42231 ksi
Specific Heat
Btu/lbm-°F 1. cal/g-°C
Temperature*
Fahrenheit (°F-32) /1.8 Celsius
Fahrenheit °F+459.67 Rankine
Celsius °C+273.16 Kelvin
Rankine R/1.8 Kelvin

73. Conversion Units
73 –
Stress [M] [L]-1 [t]-2
kgf/cm2 9.80665 E-2* MPa
ksi 6.89476 MPa
N/mm2 1. MPa
kgf/mm2 1.42231 ksi
Specific Heat
Btu/lbm-°F 1. cal/g-°C
Temperature*
Fahrenheit (°F-32) /1.8 Celsius
Fahrenheit °F+459.67 Rankine
Celsius °C+273.16 Kelvin
Rankine R/1.8 Kelvin
Thermal Conductivity
Btu-ft/hr-ft2-°F 14.8816 cal-cm/hr-cm2-°C

74. Conversion Units
74 –
pound TO g Multiply pound by 453.5924
pound TO joule/cm Multiply pound by 0.04448
pound TO joule/m (newton) Multiply pound by 4.448
pound TO kg Multiply pound by 0.4536
pound/ft TO kg/m Multiply pound/ft by 1.488
pound/in TO gm/cm Multiply pound/in by 178.6
pound/sq ft TO kg/sq m Multiply pound/sq ft
by 4.882
pound/sq ft TO pound/sq in Multiply pound/sq ft
by 6.94E-03
pound/sq in TO kg/sq m Multiply pound/sq in
by 703.1
pound/sq in TO pound/sq ft Multiply pound/sq in
by 144
radian/sec TO degree/sec Multiply radian/sec
by 57.29578
radian/sec TO revolution/min Multiply radian/sec
by 9.549
radian/sec TO revolution/sec Multiply radian/sec
by 0.1592

75. Conversion Units
75 –
revolution TO degree Multiply revolution
by 360
revolution/min TO degree/sec Multiply
revolution/min by 6
revolution/min TO radian/sec Multiply
revolution/min by 0.1047
revolution/min TO revolution/sec Multiply
revolution/min by 0.01667
sq cm TO sq ft Multiply sq cm by 1.08E-03
sq cm TO sq in Multiply sq cm by 0.155
sq cm TO sq m Multiply sq cm by 0.0001
sq cm TO sq mile Multiply sq cm by 3.86E-11
sq cm TO sq mm Multiply sq cm by 100
sq cm TO sq yard Multiply sq cm by 1.20E-04
sq ft TO acre Multiply sq ft by 2.30E-05
sq ft TO sq cm Multiply sq ft by 929

76. Conversion Units
76 –
sq ft TO sq in Multiply sq ft by 144
sq ft TO sq m Multiply sq ft by 0.0929
sq ft TO sq mm Multiply sq ft by 9.29E+04
sq in TO sq cm Multiply sq in by 6.452
sq in TO sq ft Multiply sq in by 6.94E-03
sq in TO sq mm Multiply sq in by 645.2
ton (metric) TO kg Multiply ton (metric)
by 1000
ton (metric) TO pound Multiply ton (metric)
by 2205
watt TO Btu/hr Multiply watt by 3.4129
watt TO Btu/min Multiply watt by 0.05688
watt TO ft-pound/min Multiply watt by 44.27
watt TO ft-pound/sec Multiply watt by 0.7378
watt TO hp Multiply watt by 1.34E-03
watt-hr TO Btu Multiply watt-hr by 3.413
watt-hr TO ft-pound Multiply watt-hr by 2656
watt-hr TO hp-hr Multiply watt-hr by 1.34E-03
watt-hr TO kg-m Multiply watt-hr by 367.2
watt-hr TO kilowatt-hr Multiply watt-hr by 0.001

77. Conversion Units
77 –
To Convert From To Convert To Multiply By
lbf/in2 (psi) pascal (Pa) 6894.757
pascal (Pa) lbf/in2 (psi) 1.4504E-4
g/cm3 lb/ft3 62.427974
lb/ft3 kg/m3 16.01846
lb/in3 kg/m3 27,679.90
lb/ft3 g/cm3 0.01601846
volts/mil kV/mm 0.039370
mil (0.001 inch) cm 2.54E-3
cm mil 393.70
MPa(m1/2) psi(in1/2) 910.06

78. Conversion Units
78 –
J/(g-°C) BTU/(lb-°F) 0.239006
BTU/(lb-°F) J/(g-°C) 4.184000
joule (J) cal (thermochemical) 0.2390057
cal (thermochemical) joule (J) 4.184000
joule (J) BTU (thermochemical) 9.4845E-4
BTU (thermochemical) joule 1054.350
μm/(m-°C) μin/(in-°F) 0.55556
μin/(in-°F) μm/(m-°C) 1.80
cm3/Kg in3/lb 0.027680
in3/lb cm3/kg 36.127
W/(m K) BTU in /(hr ft2 F) 6.9334713
BTU in /(hr ft2 F) W/(m K) 0.1441314
(J m)/(min m2 C) W/(m-K) 0.016667
W/(m-K) (J m)/(min m2 C) 60

79. Conversion Units
79 –
Millimeters x 0.0394 = Inches
Centimeters x 0.3937 = Inches
Inches x 25.4 = Millimeters
Inches x 2.54 = Centimeters
Feet x 30.48 = Centimeters
Meters x 3.281 = Feet
Square Inches x 6.45 = Square
Centimeters
Square
Centimeters x 155 = Square Inches
Square Meters x 10.76 = Square Feet
Cubic
Centimeters x .0610 = Cubic Inches
Cubic Feet x 1728 = Cubic Inches
Cubic Feet x 28.32 = Liters
Cubic Inches x 0.004329 = Gallons

80. Conversion Units
80 –
Gallons of
Water x 8.35 = Pounds of
Water
Pounds of
Water x 27.65 = Cubic Inches
Gallons x 231 = Cubic Inches
Pounds x .45359 = Kilograms
Kilograms x 2.2046 = Pounds
Grams x 15.43 = Grains
Watts x 0.001341 = Horsepower
Amps x Volts = Watts
Atmospheres x 14.7 = Lbs per square
inch
Horsepower x .7457 = Kilowatts
British Thermal
Units x 3.927 x 10-4 = Horsepower-hours
British Thermal
Units x 2.928 x 10-4 = Kilowatt-hours

81. L | C | LOGISTICS
PLANT MANUFACTURING AND BUILDING FACILITIES EQUIPMENT
Engineering-Book
ENGINEERING FUNDAMENTALS AND HOW IT WORKS
CONCEPTS, FORMULAS AND UNITS OF MEASUREMENT
Thank You