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Whats is difference between Earth and Neutral
ksubbu
- Feb 4th, 2009
Earth is provided to protect the equipments and appliances. It also protects us from shock hazards. Neutral is the return path for the current.
arun uday rana
- Jul 31st, 2008
Earthing of a system is to protect the system from high surge current/voltage due to lighening while neutral provides return path to the current flowing in the tranmission line.
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Generator Breakdown
What are the major causes of a generator breakdown?
Nwannaa
- Jan 22nd, 2009
A generator is made of the drive and the driven. The drive is the engine and the driven is the alternator. Breakdown can be from the engine or the alternator.If the engine is weak due to worn out ring...
naveen.rangu
- Nov 28th, 2008
These are the following reasons for failure of Generator:1) Failure in prime mover2) Failure in field windingThe above reasons are the basic requirements for to run Generator Major Problems due to:...
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How much should be the insulation resistance value of a 5KW motor and 50KW motor?
AJAY KUMAR PANDEY
- Jan 12th, 2009
IR value does not depend on KW. IR value depends on supply voltage.
haveasafeday
- Feb 5th, 2008
Insualtion resistance(IR) value of a motor does not depend upon rating(i.e. KW). It is depend upon Voltage label in which it applied.There is a example:If V=415v then IR should be min. 1.415 MohmAnd if V=6.6kv IR should be min. 7.6 Mohm
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Limit Short Circuit Current to Twice the Full Load Current
Full load SLip of a 400vstar connected 50 hz 3ph IM is 3.5 and with locked rotor full load current is circulated if 92v is applied between lines find the necessary tapping on the autotransformer so as to limit short circuit current to twice the full load current.
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Leakage Currrent
How will you calculate the leakage current?
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Inductive Load
How to design inductive load for 3 phase 440v and maximum 5 amps for star or delta?
venky_sastra
- Dec 28th, 2008
V=I*ZV=440VI=5AZ=440/5=88Z=X*LX=2*pi*Fif f=50 HZTNEN WE CAN FIND OUT THE INDUCTANCE
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What is induction motor?
ajayyadav07
- Dec 28th, 2008
Induction motor is motor that work on the principle of INDUCTION, when the stator winding is connected to the supply mains then there is magnitic flux generated due to the flow of current in stator wd...
tarun aggarwal ymca
- Sep 28th, 2008
Inductor Motor based on the principle of induction, in this when we apply single phase AC current field is set up as motor winding are closed current is induced in them which once moved through any method (capacitor start) cut the magnetic field and force is exerted on the motor
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LPF and AC Wattmeter
What is the constructional diffrence between LPF wattmeter and ordinary AC wattmeter?
jaydeepmodi
- Dec 18th, 2008
Power is the quantity which depends on the product of current and voltage and if any-one of them is -ve then power will be -ve but if both are -ve then Power will be +ve.
jaydeepmodi
- Dec 18th, 2008
An ordinary wattmeter cant be used for the ckt which has low power factor but with some modifications it can be used and this modified form is known as LPF wattmeter.. In this wattmeter there is one c...
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Ceiling Fan Rotation
The ceiling fan rotates in anticlockwise direction, Why?
pinkugkc
- Dec 16th, 2008
Motor always rotate in anticlockwise?direction?but motor shaft rotates both side?we use as a?clockwise direction or anticlock wise direction.
vijayasankarj
- Sep 9th, 2008
This is basically depends upon the angle of the blades, there is no specified reasson for that, if we change the direction without changing the angle then the air will be sucked inside.
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DC Circuit in AC MCB
Does using a AC MCB in a DC circuit affect the tripping time or the perfromance?
bittu123
- Nov 9th, 2011
No, it wont affect, since MCB works on heating effect.
It will get heat-up at same time, whether its DC or AC does not mattersaisln
- Dec 14th, 2008
Yes defenitly affect the tripping perfomence of MCB (AC) because DC has uni directional flow , the contact area of the contacts in DC MCBs is in higher ratings. There are chances of welding of contacts may also happened in some occasitions.
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Brush Alternator
What is a brush alternator?What is a brushless alternator?What is the difference between brush and brushless alternator?Which is better between brush and brushless alternator?
saisln
- Dec 14th, 2008
Compared to brush alternator, brushless alternator?is? best because voltage difference in the stator due improper?brush contact in slip-ring units cause more unbalance during loading of generator.
saisln
- Dec 14th, 2008
Brushless Alternator: In brushless alternator armature winding as a stator and field winding as a rotor. by this arrangement slip rings are not required to collect induced voltage because the armature part is?a stationary one.
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Current Carrying Capacity
What is the current carrying capacity of Moose conductor? What are the factors detrmine the current carrying capacity of any conductor?
ramakrishnan1951
- Nov 29th, 2008
APPROX. CURRENT
APPROX. CURRENT IN AMPS AT 40?C AMBIENT OVER THE TEMP. RISE OF
IN AMPS AT 40?C AMBIENT OVER THE RISE OF 40?C 45?C 960Amps 1000Amps -
Voltage Drop
How to calculate the voltage drop in cable?
ssooria
- Dec 4th, 2008
1) what is the load= KW2)from that calculate the actual current, I = KW &nb...
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Harmonics
How harmonics are produced in m/c what is its physical significance?
naveen.rangu
- Nov 28th, 2008
Harmonics are produced in machines due to non uniform distribution of flux produced by field winding in the air gap. This leads to trapezoidal wave form instead of sinusoidal wave contains multiple of? fundamental frequncy called harmonics after analysed by fourier series.
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Motor Rating
Can we use a 15kW, 1450rpm motor for 15kW, 960rpm apllication?If yes, what will be the drawbacks?
awanish75
- Nov 20th, 2008
IR value/winding resistance (should be same for three phase) should be checked in HT motor but in IT IR value will only do.
thomas_alva_edison
- Nov 20th, 2008
If the application is designed to be driven by a 15 Kw, 960 RPM motor, then:If you directly connect a 15 kW, 1450 RPM motor, you will be driving the equipment 50% faster than it is designed to operate...
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Why frequency in India is selected 50Hz
bittu123
- Nov 9th, 2011
You are right, its all bout standerisation. Once standerisation is fixed for indian (50Hz) by british, so its continuing and In america its 60 Hz according to their standerisation. But real question...
Manohar Mathur
- Nov 13th, 2008
Our eyes have special property of retentivity (capacity of retaining object for few moments even when removed). Advantage of this has been used in cinema. If frequency of power supply goes below certa...
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Motor starters
When is star-delta, Dol or VFD starters used for the motor? How many times the current rating of the motor wil be drawn on a Dol starter if no OLR used?
ibicelectrical
- Oct 31st, 2008
If there is a load like conveyor belt, chain drive, etc. then there is considerable time required by the motor to start and come to required load, so there is large current requirement at the tim...
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Electrical Transducer
What is the fuction of electrical current transducer, voltage transducer in control panel?
Raman Jain
- Oct 22nd, 2008
Tranducers are used to convert Electrcal Quantities to standard signal of 4-20mA or 0-10 V etc. The main advantage of using them that possibility of opening of CT when changing ammeters , damage(burnt...
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