why making capacity is more than breaking capacity?

Answer Posted / borys nijinski

The breaking capacity is less than make because make does
not require the arc to be extinguished. When the contacts
open, with current flowing, there is an arc created and
that arc needs to be extinguished. Extinguishing the arc
can be achieved by lengthening the arc (arc chute and air
puffer) or through an environment that does maskes the
creation of arcs difficult (eg SF6). AC arcs are much
easier to extinguish because the voltage passes through 0;
DC arcs are much harder to extinguish which is evidenced by
the lower rating of break capacity with DC as opposed to AC
for the same contactor/breaker.

Is This Answer Correct ?    3 Yes 5 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is a advantage of Self Reset Lockout ? On Fault breaker get trip & fault no longer exist then self reset lockout how inform us?

1384


how can found motors folt current ? how can disided circuit breakers caoicity and breaking capicity ?

1628


What is Surge Capacitor? Why it is use in Generator Circuit Breaker?

4617


How to calculate fault level of 11 KV system

1528


plz tel me syllabus and exam date 4 jr executive engg (electrical)

1507






explain the process of commutation in a dc machine. Explain what are inter-poles and why they are required in a dc machine.

707


What is the suitable transmission voltage?

689


what will happen if synchronous machine rotor fed from single phase ac supply 

1310


Define phase cross over?

677


What is diversity factor in electric installations?

724


Why hydropower is called renewable source of energy?

622


A 500 V shunt motor runs at its normal speed of 250rpm when the armature current is 200A. The resistance of the armature is 0.12 Ω. Calculate the speed when a resistance is inserted in the field reducing the shunt field to 80% of normal value and the armature current is 100A.

2034


Is there any Institution for giving M-tech in Electrical engineering for those who r in service? Give the details please.

1586


WHAT IS MEANING OF Gg & Gg IN hrc FUSE

2856


Why field rheostat is kept in minimum position?

725