Interested to Buy Any Domain ? << Click Here >> for more details...
What are the difference between C-Curve and D-Curve for
MCB's.
- 17 Answers
- 192266 Views
- ABB, DLF, Essar, GK companies, Nissi Engineering Solution, I also Faced
- E-Mail Answers
Answer Posted / bright spark
There is no A type.
B C and D types all consist of 2 similar parts:
The thermal trip, this is the same for all MCBs of the same
rating eg 6A.
The Magnetic trip, this is where the difference is.
B C and Ds have an increasing degree of initial "tolerance"
to overload.
B types have a limit of 3 - 5 times the rating.
e.g. a 6A MCB would trip with a surge of 18-30A.
C types have a limit of 5 - 10 times the rating.
e.g. a 6A MCB would trip with a surge of 30 - 60A.
D types have a limit of 10 - 20 times the rating.
e.g. a 6A MCB would trip with a surge of 60 - 120A.
Now you would think that the B curve would be the safest,
and it is, but not very tolerant of power surges. If you
have quite a few lights on in the house and switch on
another, this can be enough for that initial start up surge
to trip you whole lighting ring, and a reset at you consumer
unit. B types are notorious for this, but ideal for a ring
final where you don't have too many outlets, gives ideal
protection.
As you can see a type D 6A MCB can tolerate a 120A surge, so
a 32A Type D would tolerate an initial surge of 320 - 640A
before tripping!. Domestic Consumer Units will have a master
trip of @60 - 100A (80A is most common), hence why there is
never a need for type D in the domestic environment, not
unless you have a 3 phase incomer and have a car production
line in your back garden instead of a washing line!.
| Is This Answer Correct ? | 205 Yes | 17 No |
Post New Answer View All Answers
where does 22kv line starts
What is the procedure/activities to be taken to inject the current more than 2000A by using 2000A Loading Transformer?
how open delta PT works & what is its construction?
EXPLAIN WHY THE SURGE CURRENT RATING OF AN MCCB OR CIRCUIT BREAKER DECREASES WITH INCREASE IN THE RATING OF MCCB OR CIRCUIT BREAKER.
why would amp draw on neutral wire be as much as amp draw on the hot leg.
what is the use of the circle diagram
What is meant by reverse polarity and how it can be fixed?
why are u join ntpc
What is transister define the transister ammiter ,base, colector.
how load of a turbo generator can be increased
can anyone tell me can the electromagnetic waves can be reflected back?if so how &by which material it can be reflected back?please tell me so that it can help to my wireless power trasnmission device.
we are having 110 Kv,250mA Electrostatic precipitators for coal fired boilers. what will be static voltage and current after discharge and what time it will remain before earthing?
What are Contactors? How they works and what its highest rating?
What is the feedback in the control system?
how we can find of current direction(supply comming/out going direction) when a transmission line passing through sides.
