Answer / iamdon

In ACB(Air Circuit Breaker) arc extinguishing and
insulating is carried out in air medium where as in VCB
(Vaccum Circuit Breaker)it is carried out in low vaccum.
At high voltages, air inonises and losses its dieectric
properties which makes the ACB unsuitable at HT.Thats why
ACB is used at LT not at HT.

Vaccum can suastain high voltage(not ionises) and does not
losses its dielectric properties which makes the VCB
suitable for HT.

Since VCB is costlier and require more maintenance as
compared to ACB.So VCB is not employed for LT where cheaper
option as ACB is available.

Author:arbelectbit@yahoo.com

In ACS 1000 drive we are using 12 pulse converter,why don't use 3 pulse converter.

0 Answers  

---

why dc supply is given for excitation of ac alternator?how dc can produce flux?

5 Answers  

---

why we use copper earthing for neutral while for body GI.

1 Answers   Chennai Metro Rail Limited CMRL, Valeo Lighting Systems India Private Limited,

---

What is the difference between ELCB and RCCB. Please define the working of both.

6 Answers  

---

Why the Potential transformer Primary in connected to Earth?

2 Answers  

---

What is the difference between a Vacuum Circuit Breaker and a Load Break Switch?

7 Answers  

---

I have a question, I visit 01 site and face a problem, there is 2.5 ton Air Con working, when air con compressor is running at that time rectifier voltages are increasing upto 290-295 v and rectifier is giving main high alarm (rectifier is APC single phase, before starting compressor rectifier voltages was 230v. when air con is going off rectifier voltages are decreasing smoothly at its actual voltages 230v. Load on Genset phases is this: Red-13.5 amp AC (Air Con load), Yellow-1.7 amp AC (BTS lights etc.) and Blew-4 amp AC (telecom system load), Genset phase to phase and neutral to phase voltages are also ok. These are 10 sites having same system and same rectifier APC brand at every site 02 genset are working but the problem is same at all these 10 sites. What will be the reason behind???

1 Answers  

---

what are the insulation properties.

2 Answers   Cable Wireless, MAHINDRA,

---

Why phase sequence must be same in any ht motor or generator circuit?if phase sequence doesn't same whatever will be affect on circuit?

0 Answers  

---

explain the what is a drive ? 0 4 which type motor r use in the celling fan..... PCB plannet 2 13 If stator & rotor of a 3-phase induction motor have different no. of poles, will the motor run or not?? types of drives Why dc supply is used for closing and tripping coil of ht breakers. What happen if we use only ups ac supply only. ACC 1 41 how the 3phase induction motor is running in 2phase supply with help of capacitor? 1 33 what is the actual difference betwen constructional details and constructional features? 1 20 how does commutator convert a.c to d.c?

0 Answers  

---

what is deferens between HT&LT DG

2 Answers  

---

WHY HUMMING SOUND OCCURED IN HT TRANSMMISSION LINES ?

26 Answers   GE,

---