Answer / raghavendran

Consider a Generator operating in three different conditions

when operating at rated load,the AVR applies rated DC
excitation to the field.But consider a condition when there
is a sudden load throw off, the terminal voltage at the
stator will be increased.To compensate for the sudden
increase in voltage level, the DC Exc is reduced
drastically.This is called as 'Negative Ceiling Voltage'.

But when there is a sudden increase in load the terminal
stator voltage drops due to external reaction effect.Hence
the drop in terminal voltage is compensated by sudden
increase in DC Exc.This is called as 'Positive Ceiling
Voltage'.For this the response time of the AVR has to be quick.
The minimum and maximum ceiling voltages may range upto 1.5
times the DC Exc voltage at No-Load and Full Load respectively.

IF we have three 30KW motor, these motors are connected in DOL, star-delta and VFD respectively, what will be the fuse rating for the above three?

7 Answers   DOL, GSK, Ojus,

---

we have 3 single phase transformers. how will we generate 6 supply from 3 phase supply input

0 Answers   NHPC,

---

how to measure winding resistance of single phase motor?

1 Answers   Adani, Dodsal,

---

what is the use of CAPACITOR in CFL lamp?

6 Answers   Areva, Autopal,

---

why battery dc voltage become Half when we check with respect to ground for example 120volts + and - terminals and when we check + terminal with Earth thats 60volts why 60volts we can not ground the battery.

6 Answers   GE,

---

What are the questions asked in PRDC pool campus test?(bangalore)

1 Answers   PRDC,

---

diesel generator not getting start so whats problems will happen to DG and how we can start DG

1 Answers   Lodha,

---

How much weight an electrical engine can pull??

0 Answers   Maruti Suzuki,

---

Wht is the meaning of floating neutral

9 Answers   Cipla,

---

3 measuring instrument for transformers?

5 Answers  

---

Three set (each phase contain 2 cable of 400 mmsq CU XLPE AWA) of single core cables are connected to 11 KV motor of 14 MW & the switch gear supplay is taken from 11kv feeder & this supplay taken from 275 KV substation. Problem is one pair cable(L3- 2 cable ) getting very hot & gland melted and damaged in switch gear side. the other two cable haven't any more hot(ambient temp only & L3 haveing 95- 100 Degree C. The same problem happened in 275 KV substation switch gear side also where the supply taken for 11 kv switch gear. But here L2 phese cable had problem. Why it is happening like this?. The cable having temperature different at different location from gland side inthe case of 11KV feeder of 275 kv substation. why ?

2 Answers  

---

what is the use of switch disconnector fuse

1 Answers  

---