what are ABCD curves in MCBs and how we observe that curves?
- 2 Answers
- 5242 Views
- I also Faced
- E-Mail Answers
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
In convertor can we use rectifier thyristor in place of invertor thyristor with explain.
What is the simplest formula to calculate the rotor diameter of a synchronous generator?
I HAVE BEEN SELECTED FOR APGENCO A.E(ELECTRICAL) 2008.HOW MUCH WEIGHTAGE FOR INTERVIEW AND WRITTEN TEST.HOW I HAVE TO PREPARE. PLEASE GIVE INFORMATION IF U KNOW.WHAT ABT G.D THIS TIME.CALL RATIO 1:2
what is meant by brushed alternator & its working principle ?
what is relation between ct and pt ratio with multiplication factor of a energy meter? is there any other factor on which multification factor depend?
I need HT sphere gap calibration table. Can any body help me.
What does a Bode plot tell you?
What is the formula for calculating the Instantaneous Short Circuit & overcurrent for any breaker
At what factor resistance r of a conductor depends?
what is the reason the main breaker is trip during the motor is running? (some time the breaker is not trip)
new 90kw motor installed so how I purchased cable ,fuse,etc please give me technic for cable selected why always capacitor delta connection
why ss stablity limit is more transient stablity limit?
Why current shoots up in the secondary on the knee point voltage during saturation test of CT? How core saturation effects the secondary current (while the primary side is open)? What the logic behind this?
What is the numerical quantity of sqcm?
in Contactor opearation Why there is a difference in the values of the operate and release voltage in case AC supply
