Electrical E-knoweldge

                                 Variable frequency drives Hello guys...  Today i will share some basic  information about variable frequency drive (VFD). →WHAT IS VFD? vfd is nothing but variable frequency drive. it's device to control the induction motor's speed and torque mainly. by varying voltage and frequency of motor speed and torque can be adjustable in electro-mechanical combination. but there are many more use of vfd. (  VFD ; also termed  adjustable-frequency drive , “variable-voltage/variable-frequency (VVVF) drive”,  variable speed drive ,  AC drive ,  micro drive  or  inverter  drive ) VFDs are made in a number of different low- and medium-voltage  AC-AC  and DC-AC topologies                                 ...

hello guys .... lets talk about star-delta starter. The star-delta is very common in any industry. it is very basic and important.  most of interviewer asks about star-delta starter control wiring diagrams in interview.  so lets see how it works and understand it.           WHAT IS STAR-DELTA STARTER? → This is the reduced voltage starting method. Voltage reduction during star-delta starting is achieved by physically re configuring  the motor  wingdings.To do so we need star delta starter. Control wiring of star-delta starter:-                                   (This is star-delta starter contol wiring diagram) Let me tell you easy steps to make this diagram:- Parts we need in star-delta starter →3 Contactors    →1 Timer →NO,NC push-buttons →Auxillary contacts NO&NC Procedure to make wiring:- (1) Take neutral wi...

Hello guys... Today i will share information about D.O.L starter. which is direct on-line starter. The D.O.L starter are generally used for below 5 hp motor. some company's provide starters for 1-10 hp too. The D.O.L starters are very basics in any industries. These starters are used to run the induction motors.  Induction Motor draws more starting current during starting . to prevent such high amp and smooth starting the D.O.L are used. D.O.L STARTER               This is how D.O.L Starters are looks like. it may vary to manufacture to manufacture. D.O.L Starters contains :- contactor   ,overload thermal relay, NO and NC contactor for                                                                start and  stop buttons.          ...

There is two way of connection on leads of induction motor (1) star connection (2) delta connection. (1) star connection →As shown in picture above. Short either U1, V1, W1 or  U2, V2, W2 in leads and supply to Another side where no shorted leads  L1, L2, L3 .  → star connected motor only run at one third of the motor rated torque and power. So most of below 5 hp motors are star connected. → so this is how star connection has been done. (2) Delta connection →As shown in picture above. short  w2-u1 , u2-v1 , v2-w1 with links and supply either u1,v1,w1 or u2,v2,w3 →Delta connected motors run at full speed and power. above 5 hp motors are generally connected in delta connection  → so this is how delta connection has been done Note- (Do proper lugs and tight all the leads properly so that no sparking and  no cable failure in it. choose proper size of cable and always  do earthing. Never short phases in m...

* The first thing is an induction motor. The induction motor is used in 80 to 90 %  industry . It is very common motor. Induction motors are available in 1 phase to 3 phase. The advantage of induction motor is :- Low cost Low maintenance cost Ease of operation Speed Variation High starting torque Durability (i have worked on 0.5 hp to 200hp various induction motors) some of big branded company i suggest :- Compton  greaves abb siemens etc.