what are ABCD curves in MCBs and how we observe that curves?
Answer Posted / janet roadway
There is no A curve type within the IEC 60898 product
standard. The standard curves are B, C and D
Type B :
MCBs are set to trip when the current passing
through them is between 3 and 5 times the normal full load
current. The calibration temperature of this full load
current can vary from manufacturer but is generally in the
region of 30 - 40 degrees Celcius to allow for the heat
generated by the MCB within a distribution board.
Type C :
MCBs react more slowly, and are recommended for
applications involving inductive loads with high inrush
currents, such as fluorescent lighting installations. Type C
MCBs are set to trip at between 5 and 10 times the normal
full load current. Temperature as above
Type D :
MCBs are slower still, and are set to trip at between
10 and 20 times the normal full load current. They are
recommended only for circuits with very high inrush
currents, such as those feeding transformers and welding
machines. Temperature as above.
Some manufacturers produce their own specialist curves -
such as the ABB 'K' Curve which are designed for specific
applications such as tranformer feeds and motors. These
curves can be very useful.
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
What is pi controller?
If we need 4c× 50mm sq cable but it's not available so we can pull 4c×25mm sq two cables?
We have received supplies of the ordered material. payments against the supplies also released. Where ST paid 4% against form C. Meanwhile it has been observed that 25% of material supplied was defective. Please suggest whether the issuance of C form from our side would be stopped till settlement of liabilities.
Is the theorem applicable to ac sources?
can anyone send me some sample question regarding power grid corp
WHat is the requirement of installing FAST ACTING EARTH SWITCH in GIS and how is that integrated with protection system. How and when does it operate?
earth also having a gravitational force (magnetic field of north and south)but it attracts any object compare to this theartifical magnetic cant perform same as earth why?
details of oil cell size of Breakdown voltage test of tranformer oil details as per Standardswith mushroom electrodes?
What is lighting kitts.
explain wiring system
what is the Connected Load (kW) or Contract Demand (kVA)of mahindra nasik plant??
what is control supply rating of a machine
my bachelors was done with EEE now i got admit in NU with CS as course. how to answer this qns 1) why u choose cs? 2) why u changed from eee to cs
how to find the voltage's of a transmission line plzz help with pictures i am not able to understand
what questions will be asked for 11/33KV licence interview APSEB hyderabad. Can any one share question and answers.