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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
What starting device is used on single phase fractional horsepower compressor motors?
A centrifugal switch is used on the starting winding of fractional HP motors. It is used to start the motor one the start winding and at a predesignated rotational speed the switch opens to de-energize the start winding and the motor carries on running on the run winding.
Another device that should be on compressor motors is an unloader valve. Sometimes it is electrical driven and other times it is mechanical. It is used to used to unload the pressure from the compression cylinders. Without this pressure being unloaded the motor has to start against the pressure in the cylinder head and the added current draw on the motor is sometimes enough to trip the overload protection of the motor.
Is power factor defined as volt amps divided by apparent power?
No. The volt ampere (V.A) is the unit of measurement of apparent power.
Power factor is true power (expressed in watts) divided by apparent power (expressed in volt amperes).
To answer your question properly, you need to know the input power to these machines, whereas you are specifying their output powers. In other words, you really need to know their efficiencies in order to determine their input powers.
Once you have figured out their input powers, then you need to divide the power by the supply voltage in the case of the single-phase motor, and the power divided by 1.732 times the supply voltage in the case of the three-phase motor.
Incidentally, your motors' specs should either be 230/400 V or 240/415 V, NOT 230/415 V.
What part of a light bulb is neutral The centre of its screw base or the screw in portion itself?
The very centre of the bulb itself is the Hot contact. The screw in base is the neutral connection.
use a inverter to change dc to ac or couple it to a ac motor making it a motor generator.
Comment:
AC motors cannot run on DC since their principle of operation based on induction. There's an exception,however, and thats for Universal Series motor which can run on either AC or DC.
Guide to install fire smoke detector above false ceiling?
I don't believe that if you place a smoke detector inside a closed space like above a false ceiling , it will have the same effect than if it was attached to the ceiling on the occupied space side. See the related link for some general guidelines and always check local codes or with the fire marshall for specifics.
How do you change the speed of motor without change pole and frequency?
On an AC motor you basically vary the frequency on a DC you can vary the voltage.
Yes, you could, but why would you? Maintenance or fault testing on a cable rated at 600 volts involves applying the rated voltage (600 volts) and measuring the leakage current. Doing this test at 250 volts doesn't really test the cable. High potential (hipot) testing involves the application of even higher voltages for test purposes.
How do you make an electric bike from a regular one using motors and not conversion kits?
Bicycles made from small motors require the same components as a conversion kit. An engine, mounts and belt for the drivetrain needs to be installed properly. As well as shifters.
Why do you have no AC in 1995 buick riviera you have new ac control box and passenger side AC works?
== == There are three electronic actuators under the dash: one is for the defroser, one is for the bank of four passenger vents and one ( this is you) sends air to the two driver side vents, the two mid-dash vents and the two rear vents. Either this actuator is faulty, or there's a problem with the electrical delivery system; mainly, the whole climate control panel in your dash (dealer cost: about $700.00).
It maybe the Thermostat if it bad the 4.3 will quit and not start untile it cools down
Why DC-DC converter is used in telecommunication power supply instead of inverter?
DC-DC conversion offers the advantage of a bifurcated power source. AC can be rectified and filtered to supply power under normal conditions at say, 17VDC fed to a 9VDC regulator to power the circuit. A 12VDC battery can serve as an alternate feed to the circuit for times when the AC source fails -- and it is connected to the same 9VDC regulator. Another benefit of DC-DC conversion is isolation to the circuit from noisy events.
For a 3 phase motor, the voltage is 415.
Being an inductive load the power factor is commonly .85
The constant for 3 phase circuit is 1.732
You need to run the motor on no load and you use clamp meter to take the no load current. In considering the fact that on no load the measured current should not be more than 0.5 of the rated.
Assuming , under normal condition the no load current is 10 amps. Then the load current will be 20 amps.
Then from above and in using the formula P=I*V*p.f*1.732
Therefore P= 20*415*0.85*1.732.
P=12.3 kw
Thank you.
Bankole
2348035447224
What is the difference between CRGO steel and normal steel?
CRGO stands for :COLD ROLLED GRAIN ORIENTATION which is used in transformer core assembly.Transformer problem occours 40% because of using Non prime CRGO as lndustries are using frequently so life of transformer reduces.
Both have different chemical composition like amount of silicon differs.
Rest of difference you can see through net like density diffrence and their chemical and mechanical properties.
Thanks
How do you share a load in a red mobile?
Just typ the no. amount space and send to 9981.. example 091912345 2 send to 9981
600 VDC.
Can instrument transformers be used to extend the range of a moving coil voltmeter?
Not directly, as MC instruments are direct-current instruments, whereas instrument transformers only work on a.c.
What is contingency in power system?
Contngency is the nothing but the unwanted event created in the power system.due to unschedule outage and the force outage of the electrical equipment like generator, transformer or the line.
Can the amount of energy carried by a power line be increased by raising voltage?
The energy supplied by a power line is determined by its load, not by its voltage. For a given energy demand by its load, the higher the liine's voltage, the lower the resulting load current.
What do they mean when they say the meaning of life referring to electrical equipment?
They mean that life is full of electric things that we use on a day to day basis.
Why it is said to be negative resistance region?
A negative resistance region is where the current goes up while the voltage goes down, or vice versa. This is a characteristic of the esaki or tunnel diode, when it is in its tunnel region.
What does AC DC stand for in science?
AC or Alternating current, DC or Direct Current.
DC is relative to most battery voltage systems, cars, pocket radios, so on. Alternating Current mainly relates to your household electric.
Each differs in the way the electric is passed through the system, or battery.
Unless your talking about the Rock Group, then I do not know there meaning or definition. Groups have there own language for things like that.
It does not stand for After Christ / Devil Comes.
