Motor total power

Efficiency. The efficiency of a motor or generator is the ratio of its useful power output to its total power input and is usually expressed in percentage. 

For mechanical heat equivalent, the following are recommended (a) For pumps, use 50 percent of the connected motor horsepower for centrifugal pumps that are deadheaded, unless better information is available, (b) For agitators, use 100 percent of the vendor rated shaft input horsepower for the input shaft (total power less drive and bearing inefficiencies) for the actual material in the vessel. 

Rated voltage 1000 V Max. motor rated power 511 kW Cooling water cooled Dimensions Height x width x depth 1000 x 2860 x 800 mm3 Added volume of flameproof compartments 1.5 m3 Weight (total) 3700 kg Type of protection EEx de I. (b) Frequency convertor according to Fig. 6.104(a), doors of flameproof compartments opened. 

Figure 14-37 gives values that are suitable for design estimates of centrifugal-pump efficiencies. Because pump and driver efficiencies must both be considered when total power costs are determined, necessary design data on the efficiency of electric motors are presented in Fig. 14-38. 

The total power required by the electric-motor drive is. 

The degree of hybridization is a useful parameter characterizing parallel hybrid vehicles. The value of this parameter is defined as the total power of the electric motor divided by the sum of the total power of electric motor and IC engine, according to the following equation ... 

In an industrial setting, electrical measurement of the power consumption is the simplest and most commonly utilized technique. A wattmeter can be used to determine the total power draw by the motor. This measurement includes the power lost... 

When three-phase loads are balanced, for example, in motor circuits, one wattmeter may be connected into any phase, as shown in Fig. 4.18. This wattmeter will indicate the power in that phase and, since the load is balanced, the total power in the three-phase circuit will be given by ... 

In an AC circuit with an inductive or capacitive component, there are two types of power. One is true or useful power, which is capable of doing useful work, e.g., turning the rotor of a motor. The other power is reactive power that cannot do useful work. Total power, which is known as apparent power, is the vectorial sum of true power and reactive power. The ratio between true power and apparent power is known as the power factor of the circuit. 

There are two fuel cell systems coimected in parallel. The electric motor used as the aircraft propulsion system is an AC brushless external rotor type. It can be operated within a voltage range between 210 and 330 V. If the upper limit of the cell voltage is set to 0.7 V, the total number of cells should be 834. Although MEAs can be customized from an economical perspective, an off-the-shelf product is favored. An MEA with 165 cm, which is commercially available, is adequate for cases 2, 3, and 4 in Table 23.4. The required power during takeoff is also estimated based on operational experience with the aircraft Antares DLR H2 and is believed to be 40 kW. Within the lower voltage limit of the motor, this power can be reached with 960 cells... 

Motoring both Brayton units simultaneously in the initial startup may not be feasible due to the additional power required The power demand to motor just one Brayton unit represents about two thirds of the total power supplied by the solar anays (as currently envisioned), and is the main driver for their sizing on the spacecraft Adding the power required to motor a second Brayton unit simultaneously would increase the solar array sizing even more. The spaceship battery is not sufficient to start a Brayton unit. The power demand and length of time required for the startup would deplete it. Therefore all electrical power for the startup will come from the solar arrays. An alternative... 

The power P is only that imparted to the liquid by tbe impeller. It is not tbat delivered to tbe motor drive, which additionally includes losses in the motor and speed-reducing gear. These may total 30 to 40 percent of P A stuffing box where tbe shaft enters a covered vessel causes additional losses. 

The external resistance adds up to the total impedance of the motor windings and limits the starting current. It also improves the starting power factor. 

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