Interested to Buy Any Domain ? << Click Here >> for more details...
What are the maximum and minimum ratings of
MCB,MCCB,ACB,OCB,VCB and SF6 breakers?
- 2 Answers
- 32287 Views
- ABB, SK E&C, Sodexo, I also Faced
- E-Mail Answers
Answer Posted / natha
International Standard IEC 60898-1 and European Standard EN 60898-1 define the rated current In of a circuit breaker for low voltage distribution applications as the current that the breaker is designed to carry continuously (at an ambient air temperature of 30 °C). The commonly-available preferred values for the rated current are 6 A, 10 A, 13 A, 16 A, 20 A, 25 A, 32 A, 40 A, 50 A, 63 A, 80 A and 100 A[3] (Renard series, slightly modified to include current limit of British BS 1363 sockets). The circuit breaker is labeled with the rated current in amperes, but without the unit symbol "A". Instead, the ampere figure is preceded by a letter "B", "C" or "D" that indicates the instantaneous tripping current, that is the minimum value of current that causes the circuit-breaker to trip without intentional time delay (i.e., in less than 100 ms), expressed in terms of In:
Type Instantaneous tripping current
B above 3 In up to and including 5 In
C above 5 In up to and including 10 In
D above 10 In up to and including 20 In
K above 8 In up to and including 12 In
For the protection of loads that cause frequent short duration (approximately 400 ms to 2 s) current peaks in normal operation.
Z above 2 In up to and including 3 In for periods in the order of tens of seconds.
For the protection of loads such as semiconductor devices or measuring circuits using current transformers.
| Is This Answer Correct ? | 8 Yes | 8 No |
Post New Answer View All Answers
Consider three heater bank connected in 3 phase star with neutral.Each heater bank connected in each phase.So each phase get 230 volts supply.my question is,during balance condition, current flow in neutral or Not
what is method for testing CT
what kind of quetions will ask in BHEL in interview? Plz help me?
How will you define capacitance?
how to calculate the torque of a motor?
Type of motor stater detail and working detail
What is the use of oil in transformers?
what is accuracy ? in any meters , coils accuracy . how can u defined that ?
what is the method of earthing of a transformer using electrodes?
Why armature rheostat is kept in maximum position?
what happens when series resonance occurs?
EXPLAIN WHY THE SURGE CURRENT RATING OF AN MCCB OR CIRCUIT BREAKER DECREASES WITH INCREASE IN THE RATING OF MCCB OR CIRCUIT BREAKER.
Will any motor burn if voltage provided is lesser than the rated voltage???? If yes, then how is speed control possible with voltage control
please send me jindal previous aptitude and technical question and answer.my email id is deep_raj@live.com
If the feeder rating is 7.5 kw or 10 HP star-delta feeder, MCCB is taken as 63 a, contactors-32 a, how much will be the OLR rating or which range OLR should be considered when we concern about type-2 coordination?
