Answer / vijay

Before Synchronisation mainly three conditions
(voltage,speed/frequency & Phase sequence) has to be
checked which are within the limits. Reason to monitor when
any one on this parameters found not in unique, DG set's
not getting synchronised.
If the synchronisation happened in unconditional status, it
causes unbalance current will flow in the operation and
load sharring is not even. To eliminate this kinds of
occurence Dark lamp test was carried out before execution.

Answer / kj

Answer one is mostly correct. Two other factors are important. 1) the winding type (e.g. 2/3 or 5/8) as this can affect circulating neutral current. 2) phase angle at time of synchronising must be within limits to prevent high currents to pull DGs into synch.
For answer two - load sharing equipment can allow DGs of different ratings to be used in parallel. Frequency is important not RPM. The number of poles in an alternator can vary requiring a different RPM for the same frequency.
Another important factor iis governor response to load changes

Answer / benchalli nagaraj

BOATH THE DG'S ARE EQUAL RATING(KVA)
BEFORE SYNCHRONISING THE TWO DG'S TO CHECK 1)BUS VOLTAGE
2) FREQUENCY 3) RPM

In step down transformer (415/200V),mistakenly secondary side is connected to 415V for some hours, what would be result of this condition?

19 Answers   Essar, GAIL, Vizag Steel,

---

what is the method to calculate the voltage drop for number of meters Example 250volts I/p at one end if the cable length is 50 meters what could be the drop?, after 100 meters how much? needs formulae.

1 Answers  

---

what is the purpose of slope in the differential relay?why we are using two slope?but in busbar differential we are using only one slope.why?

0 Answers  

---

What are the minimum acceptable insulation resistances of insulation of underground cable suitable for 0.440kV,11kV, 33kV and 66kV?

2 Answers  

---

How we can calculate the capacity the Air Condition capacity? like 1 or 1.5 ton's, What is the means of volume of Ton's in capacity of Air Compressor? Why in ton's,? not any other Volume?

2 Answers  

---

Why do we twist copper to make cable?

3 Answers   Bhel, Integrated, MR Cables,

---

which meter used to measure a flus

2 Answers   RRB,

---

Hi everyone, I'm Lachuu, recently joined automation company as PLC Engineer. I have certain basic question, I request all big gurus and seniors to answer these question. Because this will be very helpful to me as well starters like me. How to design a control circuit (ex: pick & place - my current project) Yamaha robot PxYx series controller RCX222, using 6 cylinder double acting, plc keyence kv p16r 2 expansion unit for input and output each. How to select panel terminal mcb elcb powersupply. My main concern in some projects how to select dc power supply, mcb rcb(I came across dif bt b c d curves, but stil confusing, pls help me :-(. I would really appreciate all who are going respond to this question.

0 Answers  

---

what are the types of transformers

59 Answers  

---

what is dedicated earthing

2 Answers   Apollo Power, Student,

---

I am having a 42KW 3 phase electrical heating furnace, heating element is 80/20 nichrome material, my connections is made in such a way that 2 star connection compromising 2 coils per phase so totally 12 coils, shall if i use it unbalanced star condition (instead of 2 group of 3 phase or 1 group of 3 phase, connecting 4 phases of 5 phases) what will be the consequences and is it acceptable?

0 Answers  

---

What are the various types of BUSBAR Schemes? explain each

2 Answers   Thermo,

---