Answer / desingurajan

MCBs are miniature circuit breakers with optimum protection facilities of overcurrent only.These are manufactured for fault level of up to 10KA only with operating current range of 0.5 to 63 Amps (the ranges are fixed), single,double and three pole verson.These are used for smaller loads -electronic circuits,house wiring etc.
MCCBs are Moulded case Circuit breakers,with protection facilities of overcurrent, earth fault.it has a variable range of 50% to 100% operating current.They can be wired for remote as well as local operation both.They are manufactured for fault levels of 16KA to 50KA and operating current range of 25A to 630Amps.They are used for aplication related with larger power flow requirement.

Desingh
RAjapalayam

Answer / kadher.304

mcb its thermal operated and use for short circit rating of
mcb 63amp(max)
mccb is thermal operated for over load current and magnetic
oprataion for instant trip in short circuit condition.rating
of 63amp(9min)

Is it recommended to apply H.pot test for new cables segments after terminations or joints, however, this cable has been tested before at the manufactor by the vendor ? or only we can apply megger tests ?

1 Answers   Centroid,

---

what is different the DOL Starter and Star Delta STARTER

12 Answers   Schwing Stetter,

---

in the exciter the power is feeded from battry or control or whatever.and we need it in the generators for the stating . do we need it in the shutdown also?i mean the exciter>

2 Answers   Shell,

---

he compression ratio for a petrol engine generally lies between

0 Answers   Caterpillar,

---

the circuit having same properties in either direction is known as.......

2 Answers  

---

Assuming that a dedicated neutral earthing transformer is provided for each GT generator, when the two generators are running in parallel, has consideration been given that the earth fault current from one generator stator winding be split between the two neutral earthing transformers? If so, what adverse impact will this have on the operation of the 59N and 27TN devices?

0 Answers   Quest,

---

what is meant by skin effect ?

3 Answers  

---

What is meant by analogous system?

0 Answers  

---

iam preparing for rrb section engineer post in electrical branch.suggest the right textbook for my reference.fromwhere i will get the previous q.papers?

0 Answers   RRB,

---

Operation of isolators.

0 Answers   KSEB, L&T, Siemens,

---

differentiate between one way two gang switch & two way one gang switch, used in designing the loads of building.

1 Answers  

---

The screw thread commonly used for transmission of motion is one of the following types of threads

0 Answers   Caterpillar,

---