Answer / cae

Plc basically contains Inputs and outputs along with CPU. programme written in ladder logic or in any other language like FBD,ST,IL it is stored in PLC memory which deals with CPU. Field sensors are connected to the input card of plc as a reference signal or getting feedback from the field by sensors. so according to the logic plc sends a signal to the output card which correspondingly enables the Electrical output,it may be a motor contactor coil or drive through a relay for safe operation and plc sends the output signal with very low voltage level enough to enrgize the relay coil or contactor coil or an SSR(solid state relay) This is the way how plc gives commands to electrical. and ***Communication plays a vital role for plc operation

what is meant by distance protection ? how distance protection relay function ?

1 Answers   ABB,

---

what is the diff. btwn. electronic regulator and ordinary rheostat regulator for fans?

3 Answers  

---

if dc motor can operate by ac supply ? if its possible means how ?

2 Answers  

---

what is difference betwen genrator and alternator?

3 Answers   Tanfac,

---

what's the difference between abs/inc encoders. apart from the position remembrance what are all the other differences. and what's mean by grey code.

0 Answers  

---

---

what is the meaning write of AC1,AC2,AC3 .....power contactor

7 Answers   ABB,

---

how many types of motor can be used in washing machine

0 Answers  

---

What is the relation between the Peripheral speed(N) , no.of poles(P) and diameter(D) of a cylindrical rotor alternator ?

5 Answers   NTPC,

---

what is active power and rective power and power factor

1 Answers  

---

why we use to transmit the power in three phases intead of single phase ?

4 Answers  

---

in 11kv/400v transformer when only one phase of 11kv supply fails what happens to sec voltage and why

6 Answers  

---

what is automatic voltage regulator and it is used?

2 Answers   HAL,

---