g is the gross-torque in N-m. If a transformer is 100% efficient, then the input power will equal the output. It is simply defined as speed times torque (the rotational equivalent of a linear force). I a2 R a = Copper loss in the armature winding. Pe mean effective pressure, MPa. As a result, the rotor input multiplied by (1 - s) equals the gross mechanical power developed. The power factor formula can be expressed in other ways: PF = (True power)/ (Apparent power) OR. The permanent magnet synchronous motor working is dependent on how the rotor's static magnetic field and the stator's revolving magnetic field interact. Ns = Synchronous speed s = slip of the motor sb = breakdown or pull-out slip E1 = stator voltage or input voltage E2 = Rotor EMF per phase at a standstill R2 = Rotor Resistance Per Phase X2 = Rotor Reactance Per Phase V = supply voltage K = rotor/stator turn ration per Phase Starting Torque Output . The rated power factor of the motor. Php = horsepower delivered by the electric motor (hp) n = revolution per minute (rpm) Alternatively Tftlb = Php 5252 / n (1b) where Tftlb = torque (lbf ft) 1 ft lbf = 1.356 Nm Torque in SI units can be calculated as TNm = PW 9.549 / n (2) where TNm = torque (Nm) PW = power (watts) n = revolution per minute (rpm) VIa= EbIa + Ia2 Ra .. (2) Where, VIa = Input Power supply (Armature Input) EbIa = Mechanical Power developed in Armature (Armature Output) Ia2 Ra = Power loss in armature (Armature Copper (Cu) Loss) Related . Pneumatic systems use compressed air to move object using cylinder, motor or other mechanical parts. The efficiency of a motor is determined by dividing the mechanical power output by the electrical power input (formula 1). In adjusting the excitation voltage is a constant power regulation (motor output power is basically constant) T = 9.55*P/N, T output torque, P power, N speed, the motor load has a constant power and cross-torque, constant torque, T constant, then P and N is proportional relationship. The units of power are generally calculated in either Watts, which are Joules/sec. 5252 = James Watt's original test data of 33,000 / 2. This means that this load draws reactive power. Later it was expanded to different types of piston engines, electric motors, turbines and other machinery. The factor that measures the input power is the motor efficiency (EFF) normally in percent. To determine the percentage slip, rotor copper loss, rotor output, and efficiency of the motor, perform the following function: Percentage slip // The synchronous speed of the motor = (50 120) / 6 = 6000 / 6 = 1000 rpm Be careful with the nameplate ratings on the motor. Let's say we want to lift a 0.7kg mass using a 4cm diameter pulley. \displaystyle P_m = \frac {P_s} {\eta_m} P m = mP s. Motor Slip. V = voltage. At this point it is drawing the maximum amount of current and applying maximum torque. The Output Power of Series DC Motor formula is defined as the power of the series dc motor at the output side and is represented as Pout = s* or Output Power = Angular Speed*Torque. It is motor speed and torque - the turning force of the motor. We get the 3-phase current formula like this: I (Amps) = P (kW) 1,000 (V (Volts) PF 1.732) Using this power formula, we can, for example, do a 3-phase motor kW to amps calculation. For Calculating DC motor output power, we need to multiple above formulae with motor efficiency. P = 3 V * I * PF I = P / (3 *V * PF ) = 10,000/ (1.73*400*0.85) I = 17 A Then, S =3 V * I S = 1.73*400*17 = 11.7 KVA Note that, the active power is greater than the apparent one. Hp = Torque X RPM 5252. Efficiency (). Flow Rate Q (litres/minute), Power N(kW) and Pressure P (bar) In order to calculate the required Power N(kW), you must enter the following figures:-Pump Flow Q, this is litres/minute. The electrician makes the following measurements: Measured Values: V ab = 467V I a = 36 amps . Power has to be in Watts = kW as on the nameplate x 1000. For motors we always quote speed in rpm. Electrical power input to the stator, P in = 3V L I L cos A part of this power input is used to supply stator losses which are stator iron loss and stator copper loss. Equation (1) is the power equation of DC motor. Let, V = Supply voltage. Solution: Rotor speed = m = 1200 r/min. The mechanical power developed (P m) by any synchronous motor can be expressed as P m = 2 N S g 60 W a t t s. ( 1) Also, the mechanical power developed (P m) is, P m = V I a C o s ( ). This is why testing is so important. The motor's voltage has been specified, and the current at various torque levels has been shown. Note: The voltage V (V) to be measured between the armature terminals and DC current I (A) will be the armature . To calculate this, you need to know the Motor Input Power - the power input into the motor from the mains electricity supply. = Internal or Impedance angle = Tan -1 (X r per Z s ). Initially with low power outputs, efficiency is poor due to the constant losses. n number of crankshaft revolutions per minute. 3-phase motor amps calculation with power rating in kilowatt (kW): Input and output power Electrical power is calculated by multiplying voltage (in volts) by current (in amps). Figure 3 Relationships Between Power, Current, Power Factor and Motor Load Example: Input Power Calculation An existing motor is identified as a 40-hp, 1800 rpm unit with an open drip-proof enclosure. If your situation or problem presents data in different units, you will have to convert. If you need to know the output torque of the gear . Although the power output varies from . This . The excess of power requirements are the motor losses developed due to the currents circulating in the rotor and stator windings, The friction and windage, the magnetic losses in the laminations and structural frame. The efficiency of the motor is defined as the mechanical power output divided by the electrical power input at each calculation step. Example : We have 1 unit Induction Motor with 30 horsepower (hp),running with 34.9 amps for amperage load and 460 volts 3 phase and power factor value is 0.75 and motor efficiency is 85%. However such motors do not exist. The power equation counts: PEl.Motor = PInput - PElectronics The motor voltage is always lower than the supply voltage. Typically around 0.86. = Load angle. A goal for vehicle design is therefore to maximize this ratio and optimize the overall system efficiency by using the biggest propeller possible without overloading the motor. At around 10% of the . Horsepower (HP) = (Torque Speed)/5252. What is Reactive Power Hydraulic and Pneumatic systems have wide variety of applications in the industry includes automobile, packaging, medical and construction . How to calculate power factor. When a Hydraulic Motor is being driven the Output Torque M(Nm) can be calculated by following these steps: Pressure P (bar), typical pressures for hydraulic motors would be up to 250 bar. I a = Armature current per phase = E r per Z s. Z s = R a + J X s = Synchronous impedance. Where; HP = Horsepower (1HP = 0.7457kW) t = Motor torque. A DC shunt motor (also known as a shunt wound DC motor) is a type of self-excited DC motor where the field windings are shunted to or are connected in parallel to the armature winding of the motor. The motor takes 50 kW at 960 rpm for a certain load. EFF = (HPshaft output / HPinput) x 100. STEP 1 f = frequency of three-phase power supply And #pp = the number of pole pairs How to Calculate Motor Poles Since the number of poles is equal to the number of permanent magnets in the rotor, the simplest way to determine the number of poles is to count the magnets manually. They are . This calculator page enables you to calculate three parameters important to designing a hydraulic power pack. The power input (current times voltage) is a good indicator of the mechanical power output. Pneumatic cylinder force calculations formulas includes force calculation, air consumption, Output power. If the motor has 100% efficiency all electrical power is converted to mechanical energy (Pin = Pout). Efficiency can be expressed in simplest form as the ratio of the output power to the total input power or efficiency = output power/input power. The result for (3 phase) reactive power is the same whether the motor is connected delta or wye (Q=SQRT(3)VISinAngle. PF = power factor= Cos P = 3V I cos =active (true or real) power (Watts) S = 3V I= Apparent power (VA, volts amps) hence, Power factor of motor formulais Cos =3 VI Cos / 3 VI From the following diagram, you can easily understand why the power factor is cosine between apparent power and a real power. Where: P out =Output power (W) t=Torque (Nm) w=Angular speed (rad/s) Some of the most useful conversion factors are: 1 mile = 5280 feet Performing a 3-phase power calculation means using a simple formula relating the power to the voltage, current and a power factor describing the efficiency of the circuit. The key difference between working out power for 3-phase and single-phase systems is a factor of the square root of three. Most automotive engines produce power in a wide band of the engine's speed. Hence if the PWM reference voltage is set to its maximum value of +5V, then the motor should run at 4000 rpm. The motor is 12-years old and has not been rewound. Power Equation of a DC Motor. Where V L and I L are the line values of stator supply voltage and current . The various stages in this conversion are called power transfer stages in an induction motor. Motor power may be calculated as the shaft power divided by the motor efficiency. The efficiency of the motor is calculated as mechanical output power divided by electrical input power: Motor Efficiency = P mech / P elet = P out / P in. This means the motor is overloaded. Also, a given motor draws more current as it delivers more output torque. Typically around 95%. This may be seen also from the graph of the function in figure 1 (b). 7.08.6.1 Utilization efficiency. Recall that 1 hp = 550 ft-lb/sec. 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