What are the difference between C-Curve and D-Curve for
MCB's.
Answer Posted / simon
Awesome thread with a lot of almost correct and mostly
correct answers.
The challenge is knowing to which standard a particular
breaker was manufactured.
AS/NZS 4898 specifies:
B Curve between 3 In and 5 In
C Curve between 5 In and 10 In
D Curve between 10 In and 14 In
This was an update to AS 3947.2 which specified:
B Curve between 3.2 In and 4.8 In
C Curve between 7 In and 10 In
D Curve between 10 In and 14 In
The application notes in #11 and #13 are pretty much spot on.
Now lets assume we're only using AS/NZS 4898 breakers.
Lets assume we're using a Clipsal C60 10A B curve breaker.
The breaker should operate electromagnetically (<0.2s)with
an inrush current greater than 30A (3 x 10A).
The same 10A breaker however with 15A of current will not
trip electromagnetically but will trip thermally between 30
and 600 seconds after load is applied.
A C curve breaker of the same type should not operate
electromagnetically at either 15A or 30A. It should operate
thermally between 30 and 1000 seconds after a 15A load is
applied and between 6 and 50 seconds after a 30A load is
applied.
Note the distinct difference between and instantaneous /
electromagnetic trip and a delayed / thermal trip.
| Is This Answer Correct ? | 10 Yes | 4 No |
Post New Answer View All Answers
A 3-phase IM is supplied from 50 Hz system. It runs at speed of 1440 rpm and slip equal to 4 %. Calculate number of pole pairs. A 1 B 6 C 2 D 3
I had applied for JE in PSEB, Can you pls send me the Question bank for related to my field
How to minimize the eddy current losses?
internally connection of photvoltic module
how many types are their in switchyard or substation(like D,I TYPE), what is differant between them
How much weight an electrical engine can pull??
DRAW ACIRCUIT DIAGRAM OF 100 KVA 415V/55-0-55V DELTA TO STAR TRANSFORMER
Give the expression for the frequency of oscillations in an op-amp sine wave oscillator?
BSNL TTA EXAM QUESTION
What range of speed can you get with the armature control method of speed control of d.c. Shunt motor?
what is counter poise conductors
How many turns are there in primary winding? (In Transformer)
What would be the size of wire used for 2 Ton of window A.C?
what is the breaking capacity and making capacity of circuit breaker and how
1.main parts of generator? what is used A-check,B-check,C- check? 2.what is FM200 system in data centers? 3.difference between pac,ahu?